Title of the I~iventio~t:
DISTRIBUTED ELECTRlC POWER GENERATION SYSTEM, CONTROL STATION, AND
5 METHOD OF CONTROLLlNG THE SAME
Technical Field:
The present invention relates to a distributed electric power generation system
connected with a power transmission grid network, and more patlicularly to a distributed elcctric
10 power generation syste~iai nd a cotltrol station that perform operation control ofeacli of electric
power generation means so as to optitnizc a running cost, and a method of controlling the satlie.
Background of the Invention:
Sotne distributed electric power supply systems have been proposed in which a plurality
15 of electric power generation facilities are connected to demand loads via a power transmission
grid network such that operation contml of each of the electric power generation facilities can be
performed.
Proposed examples of distributed po\ver supply systetns include Patent Literatures 1 to
3.
20 A distributed electric po\tCers upply system disclosed in Patent Literature 1 has a
plurality of electric power generating apparatuses that supply elcctric po\ver to power loads and
an electric power gc~ierationn umber controller opcrable to control the tlumber of the electric
po\ver generating apparatuses \vhich are operating. The plurality of electric power generating
apparatuses and the clcctric power generation nt~mbcrc ontroller are connected via a
25 cotnmunication nct\\,ork. Wheti a plurality of electric power gellerating ap[>aratuses give a
whole amount of po\\!er loads in the system ici a distributed tnannel; the electric power
generation nuntber controller determines the number of operating or active electric po\trer
generating apparatuses all ofwhich generate the amount of electric power equal to or greater
than thresholds by removing a small amount and i~lsuficietlet lectric pourer generation.
30 A distributed clcctric power supply systetll disclosed in Patent Literature 2 neternlines
active or operating electric power getlerators so that minimize po\\cer tratlsmission loss (suppress
po\ver flow) i l l order to consider inefficiency resultit~gf rom power transtnission loss in a power
transmission tletwork.
A distributed electric power supply system disclosed it1 Patent Literature 3 performs
control for separating certain power loads (power loads of less priority) when a commercial
power supply is interrupted and a distributed electric power supply cannot cover the total amount
of electric power required. Fu~thertnoret,h is system receives an input of a power cut period
from an administrator and predicts and calculates an electric po\\Ier demand for that period
5 (power cut period) with an electric power demand prediction tool, thereby verifying the
suflicicncy of the demand.
Additionally, while smart grids for a commercial po\ver supply are being developed,
other systelns are also being developed to construct and operate relatively s~nalpl ower
transmission grids within a predetennined area independently of the infsastructural nehvork
10 (commercial power supply network). The grids operated in the predetermined area are referred
to as inicrogrids, picogrids, or cells. Tl~epr edetermined area is set in an appropriate inanner at
each llccessary time. For example, the predetermined area is formed by a rcgional area, a city, a
building, several houses, or the like. Fu~thennorea, grid nehvork fora plurality of buildings
such as a school or a hospital is also being developed.
15
Prior Art Literature:
Patent Literature
Patent 1,iterature I 1: JP-A 2009-1 89226
Patent Literature 2: JP-A 2005-1 43238
Patent Literature 3: JP-A 2008-01 1612
Snmmary of tile Invention:
Problem(s) to be Solved by Invention
Many proposals have considered balanced control betlveen electric po\ver generated in a
25 distributed electric po\\iel. gencration syste~na nd a large nu~nbero f demantl loads.
Howevel; the inventor has found one problem in an aspect of a running cost upon
operating a distributed electric power generation system connected xvitll a power transniission
grid network so as to cover a predetermined area.
Here, specific problems will be described with use of the exe~nplatyp rior art references.
The distributed electric power generation control system of Patent Literature 1
~naintainst he po\\'er generation efficiency at a certain level or higher and operates as many
electric power generators as possible to follo\v changes of the detnands. On the other hand, this
system suffcrs from significant loss when a fuel loss generated upon turning the electric po\lrer
generating apparatuses on and off is taken into accoutit.
The distributed electric power generation system of Patent Literature 2 selects highefficiency
electric power generators as active electric power generators in co~isiderationo f power
tra~ismission losses and the like. NevetZheless, this system similarly suffers &om a wasted fuel
cost caused by a small amount of electric power generation.
5 This also holds true for the distributed electric power generation systenl of Patent
Literature 3.
Furthermore, desirable e~nbodimentso f a distributed electric potver generation spstelil
for reducing a ronning cost with maintained quality of electric power or the like have been
examined in consideration of a \vide variety of electric power conditions in the \\lorid.
10 Moreovel; systems that are generally excellent or are excelle~iut nder certain conditions
have been examined along with the aforementioned aspects in order to efficiently use existing
electric power networks (commercial power systems), electric power facilities, and consumer's
facilities.
'The present invention provides a distributed electric power generation systelil that can
15 reduce a running cost thmugh selective control of active power generators that achieve an
increased efficiency of distributed electric power generation that covers a predetermined grid, as
co~uparedto existing systems, and a neth hod of controllilig such a distributed electric power
generation system.
Means for Solving the Problems(s)
20 A distributed electric power generation system according to the present invention is
characterized by comprising: a plurality of electric po\ver distribution stations operable to
receive electric power &orn an external power source and generate electric power in a balanced
Inanner; a power tratlsmission grid network cotinccted to the plt~ralityo f electric power
distribution stations for supplying received electric power to a plurality of demand loads using
25 electric potver; and a control station operable to acquirc information on an electric power
distribution period used to calculate a period during \\illich electric power supply is needed,
acquire an amount of power supply demand to be supplied via the power transmission grid
nehvork during the period during whicli electric po\ver supply is nccdcd, the period being
determined from the acquired infomlation on the electric po\ver distribution period, and select a
30 less costly coolbination of one or a required number of electric po\ver generation facilities for
supplying electric power to the plurality of demand loads based upon a start and stop cost and a
running cost of each of the electric power distribution stations ill accordance \\tit11 the calculated
electric power distribution period and tlie amount of power supply demand.
A control station for distributed electric po\vcr generation according to the present
invention is characterized by comprising: a power cut status detection part operable to acquire
inforntation on an electric power distribution period used to calculate a period during wliicli
electric power supply is needed upon an interruption of electric power supply from an external
power source in order to sl~pplyel ectric powcr to a plurality ofdemand loads connected to a
5 power transmission grid network with a plurality of electric power distribution stations that can
generate electric po\ver up011 the interrc~ptioo~if tlte external power source; an electric power
demand monitor part operable to acquire an amount of power supply demand to be supplied via
the power transmission grid network during the pcriod during which electric power supply is
needed, tlie period being determined fiom the information on the electric power distribution
10 period; and an operating electric power generation facility determinatioti part operable to select a
less costly combination of one or a required notnber of electric power distribution stations for
supplying electric power to the plurality of demand loads as electric power generation facilities
based upon a start and stop cost and a running cost of each of the electric power distribution
stations in accordance with the calculated electric powcr distribution period and the amount of
15 power supply demand. A method of controlling distributed electric power generation according
to the present invention is characterized by comprising: an information acquisition step of
acquiritig inforniation on an electric power distribution period used to calculate a period during
wllich electric power supply is needed upon an interruption ofelectric power supply fiom an
external power source in order to supply electric power to a plurality of demand loads connected
20 to a poxver transniission grid nehvork with a plurality of electric power distribution stations that
call generate electric po\ver upoil the interruption of tlie external po\ver source and acquiring all
amount of power supply demand to be supplied via the power transmission grid network during
the period during whicli electric po\ver supply is needed, the period being determined from tlie
acquired information on the electric power distribution period; and a selection step of selecting a
25 less costly co~nbinationo f onc or a required nuntber of electric powcr distribution statiotis for
supplying electric power to tlie plurality of demand loads as electric power generation facilities
based upoil a start and stop cost and a running cost of each of tlte electric power distribution
stations in accordance with the calculatcd electric power distribution period and tlie amount of
power supplp deliland.
30 Advantageous Effects of Invention
According to the embodiments ofthe present invention, there can be provided a
distributed electric power generation systetn tltat can reducc a running cost thro11gI1 selective
control of electric power generators to be operated that achieve an increased eficicncy of
distributed electric po\\'er generation tltat covers a predetermined grid, as compared to existing
systems, and a method of controlling such a distributed electric power generation system.
Brief Deseriptio~o~f the Drawings:
Fig. 1 is a system configuration diagram showing a distributed electric power generation
5 system according to Embodiment 1.
Fig. 2 is a configuration diagram of a centralized control station 100 according to
Efnbodiment 1.
Fig. 3 is a flow chart ex plan at or)^ of an operation example of the centralized control
apparatus 100 according to E~nbodiment 1 in a case where the centralized control apparatus 100
10 detects a po\ver cot.
Fig. 4 is a flow chart for detennining electric power generation facilities to be operated
for power loads under the direction of an electric power distribution station having a power cut
period that is equal to or sliolter than a power cut period threshold according to Embodinlent 1.
Fig. 5 is a flow chart explanatory of an operation example of a control station in a case
15 where a power cut is detected in Embodi~nen2t .
Fig. 6 is a systelu configuration diagratn showing a distributed electric power generation
system simplified to explain operations according to Embodiment 3.
Fig. 7 is a flow chart sho\ving an example operation of detennining a system
configuration fora group of power loads in Embodi~nen3t .
20 Fig. 8A is a diagram illustrating the amount of demand in each of the demand loads.
Fig. 88 is an explanatory diagram illustrating a system configuration in a case wilere
pairs of the electric power generation facilities being operated and groups of the demand loads
are derived.
Fig. 9 is a flow chart showing an example operation of determining a system
25 configuration for a group of powcr loads according to Embodiment 4.
Fig. 10 is an explanatory diagram showing schedule table information illustrating a
determined system configuration for each unit of ti~neac cording to Embodiment 4.
Fig. 11 is an explanatory diagram showing demand prediction table information
illustrating a list of electric po\trer demand predictions that is used to determine a system
30 configuratio~fl or each unit of time according to Embodiment 4.
Fig. 12 is an explanatory diagram showing reasoliability determination table
information illustrating rcsults of determining the reasonability as possible system cotifigurations
based upon an operation rule in ordcr to determine a system configuration for each unit oftime
according to E~nbodimcn4t .
Fig. 13 is an explanatory diagram showing results of selecting a combination that
acliieves a lower cost according to the amount of power supply demand (predicted demand)
during the electric power distribution period (the operating unit of time) for each of the
reasonable system configurations wl~ena systetn configuration for each unit of ti~ueis to be
5 determined according to Enlboditncnt 4.
Fig. 14 is a system configuration diagram showing a distributed electric power
generation system according to Embodiment 5.
Fig. 15 is a flo\v chart showing an example operation of selecting a system
configi~rationf or a group ofpower loads according to Embodi~nent5 .
10 Fig. I6 is an explanatory diagranl showing schedule table information illustrating a
determined system configuration for each unit of time according to Embodiment 5.
Fig. 17 is an explanato~yd iagram showing reasonability determination table
infortnation illustrating results of deterlnitling the reasonability as possible system configorations
based up011 an operation rule in order to determine a system configuration for each unit of time
15 according to E~nbodimen5t .
Fig. 18 is an explanatory diagram showing results of selecting a co~nbinationth at
achieves a lower cost according to the atnount of po\ver supply demand (predicted demand)
during the electric power distribution period (the operating unit of time) for each ofthe
reasonable system configurations when a system configuration for each unit of time is to be
20 determined according to Embodiment 5.
Fig. 19 is a syste~nc onfigoration diagram sho\\ring a distributed electric power
generation systetn according to E~nboditnent 6.
Fig. 20 is an explanatory diagram sliowing schedule table information illustrating
determined system conligurations for each unit oftime according to Entbodi~ncn6t .
25 Fig. 2 1 is an espla~iatot.)dt iagram showing reasonability determination table
informatiot~ illustrating the restrlts of determining the reasonability as possible system
configitrations based upon an operation rule when a system configuration for each unit of time is
to be determined according to Embodi~uen6t .
Fig. 22 is an explanatory diagram showing selection result table information illustrating
30 results of selccting a combination that achieves a lower cost according to the amount of power
supply dcmand (predicted demand) during the clectric power distribution period (the operating
unit of titile) for each of the tleaso~~absley stem configuratiaris {vf~erar systern corffigc~mtionf or
each unit oftime is to be determined according to Embodiment 6.
Modc(s) for Carrying Out the It~vention:
Scveral embodiments of tlie present invention will be described belo\\' with reference to
the drawings. Ideas described in each of the embodiments inay properly be conlbined with
ideas of other embodiments. Thos, those ideas can be combined with each other as needed.
5 [Embodiment I]
Fig. 1 is a system configuration diagram showing a distributed electric power generation
system according to Embodilnent 1.
The distributed electric po\ver generation system I illustrated in Fig. I can supply
electric power to a plurality of demands (demand loads) present in a predetermined grid (also
10 referred to as a sector or a cell) from a plurality of electric power generation facilities along wit11
a commercial power supply.
As illustrated, the distributed electric po\\ler generation system I includes a centralized
control station 100, a plurality of electric power distribution stations 200 (200A-200C), and
power transmission grid networks 300 (300A, 3008). Tlic distributed electric power generation
15 system 1 is connected to a commercial power system as an external power source and demand
loads located at various places within a managed area. In Fig. I, the demand loads 1,2, . . .
represent consumers who consume distributed electric power, ssucli as houses, buildings, schools,
and hospitals.
The role of the centralized contml station 100 is to supply electric power to detnand
20 loads connected to the systeni (demands for power supply upon a power cut) at a low cost when
the commercial power supply is interrupted.
Therefore, the centralized control station 100 collects and acquires infornlation on
electric power at various places, which includes at least information on an electric power
distribution period and the amount of power supply detnand. Then the centralized control
25 station 100 instructs or operates vat.ioos places in the system individually or collectively on
control of the electric power generation, regulation of demands, switching oftlie systems, or the
like. For system operation at that time, one or a required number of electric power distribution
stations (electric power generation facilities or electric po\ver generation means) are selected and
operated to reduce the total running cost during an electric po\\rcr interri~ptionp eriod of the
30 co~nlnercial power system in accordance with the electric power interruption period and the
amount of po\ver supply demand that meets the demands during the interruption period. For
tlle collection of the information, the information may dircctly be collected via an information
net\vork, or an input may be received artificially. Fudhermore, tlic interruption period or tlie
amount of demand [nay be calcc~lateda nd processed in the centralized control station 100 by
prediction or estimation, and the acquired information may be used. The information network
may be formed by a wired or \\rircless communication net\vork. Furthermore, a power line map
be used for communication.
The electric po\ver distribution stations 200 can receive power supply from the
5 commercial power system as an external power source and distribute it to the demand loads.
Additionally, each of the electric power distribution stations 200 includes one or more electric
power generation facilities (electric power generation means) therein and can distribute the
generated electric power to the demand loads. The external power source may be power supply
from another adjacent grid or the like other than the commercial power system. Each of the
10 electric power distribution stations 200 may include a plurality of electric powver generation
facilities as in the electric power distribution station 200B. Each of electric power generation
facilities installed in one electric power distribution station 200 may be managed by the
centralized control station 100 or may integrally be managed at the electric powwrer distribution
station.
15 Each consu~neor r a manager of the distributed electric power generation system 1
installs the electric power generation facilities. Thos, the electric power generation means in
each of the electric power distribution stations 200 is prepared so that it can be operated opon a
power cut.
The electric power generation facility in each of the electric power distribution stations
20 200 can employ a general emergency power supply facility or a facility used for a hybrid electric
power generation facility. Examples of such facilities include a diesel generatol; a battery, a
file1 cell, a gas turbine generator, a steani tl~rbineg enerator; a biomass generatol; and the like.
The electric power generation facility may includc a facility that continc~ouslyg enerates and
distributes electric power to demand loads, s~ic11a s a solar power generation facility, a wind
25 po\vcr genet.ation facility, and a 1iydl.anlic power generatioil facility. Those electric power
generation means are provided merely by way of example and are not intended to liinit the
electric power generation means.
Each of the electric power distribution stations 200 provides a connection point where
electric power is bought from a general electric po\vcr company. Any mechanism for selling
30 electric po\t8er may be provided as needed. Furtliern~ore, any mechanism for interchanging
electric power with other distributed electric power generation systems (other sectors or cells),
wvhich may be external power sources, may bc provided as needed.
The electric powver distribution to the demands by each of the electric power distribotion
stations 200 may not be synchmnized with the comrncrcial powwrer sopply. For example, electric
po\ver may be supplied to the demands at a frequency different from that of the colnn~ercial
po\lrcr supply. Electric power may be supplied with different types of currents (AC or DC) or
with ditferent voltages. For example, \\(hen the commercial power systelil is an altematingcurrent
polver source, each of the electric power distribution stations 200 may be configured to
5 receive electric power fi.0111 the comlnercial power system via ACIAC conversion or ACIDC
con\rersion.
The power transmission grid networks 300 are connected to the electric power
distribution stations 200 and the dcmand loads. Tlle power transmission grid netlvorks 300
supply electric power received from the commercial power supply or the electric power
10 distribution stations 200 to the demands using electric powver (demand loads).
In short, the powver transmission grid networks 300 may be formed only by electric
powwrer distribution lines having no controlled parts. 'The power translnission grid networks 300
may include a transformer or a breaker. On the other hands, the power transmission grid
networks 300 may be configured to change electric power distribution paths such that the electric
15 power distribution stations 200, the demand loads, and the system can be separated. Tile
electric power distribution paths may be swvitcl~ed by operation of a relay or the like. Fig. 1
shows a polver transmission grid having two separated systems (300A and 300B).
As illustrated, the power transmission grid net\vorks 300 are connected to the electric
power distribution stations 200. The power transmission grid networks 300 supply electric
20 power received fiom the commercial power system andlor any or all of the electric power
distribution stations 200 to one or niore demand loads wing electric powel:
The power translnission grid networks 300 may he controlled by the centralized control
station 100 or by each of the electric po\ver distribution stations 200. Furthermore, a hornan
may s\vitch the paths based upon instructions issued by the centralized control station 100.
25 Now an example oftlie co~ifignratio~oif the centralized control station 100 will be
described.
Fig. 2 is a configuration diagram o f the centralized control station 100 according to the
present embodiment. As illustrated in Fig. 2, tlle centralized control station 100 includes an
electric powver demand monitor part 110, an operating or active electric power generation facility
30 determination part 120, a power cut status detection part 130, and a communication part 140.
In this configuration example, all information is received from and transmitted to the
information network via the communication part 140. The communication means is not limited
to one type. Power line communication, wireless commonication, or \\,ired communication
lnay properly be used depending upon the system contigoration to be constructed.
The electric po\tfer demand monitor part 110 continuously monitors electric power
demands at the demand loads (consu~ners)c, alculates the total demand, and notifies the
operating electric power generation facility determination part 120 of the total demand, which is
an aggregated total of the monitoring results. The total demand is the amount of electric powcr
5 that needs to be supplied at the presetit time. In other ~vordst,h e total demand is electric powcr
consumption of all ofthc de~lla~ltoda ds under the direction of the system. The amount of
power supply demand right after the present time and during the electric powcr distribution
period can be estimated based upon this total de~natld. Forthern~oret,h e amount of power
supply demand may be cstitilatcd or predicted precisely by the use of various kinds of data wllich
10 have already been collected and \\~hichs erve to esti~natee lectric power variatiotls during each of
time periods. Moreovel; the electric po~verd etnand monitor part 110 may perfortii acquisition
(notification, estimation, or prediction) of the amount of power supply demand separately for
each of the electric power distribution stations or each of the demand loads and notie the
operati~ige lectric power generation facility determination part 120 of the amount of power
15 supply demand.
The operating electric po\ver generation facility detennination part 120 acquires
information on the electric power flows of the electric power distribution stations 200 (whether
the system power supply is used, \vhether electric power generation means is used, 01. the likc)
via the comtnunication part 140 and determines electric power generation means to be operated
20 (and o~~tpuotrs p ower transmission paths as needed) with use of a selection part 121.
Furthe~morct,h e operating electric power generation facility deter~ninationp art 120 notifics the
electric power distribution stations 200, the poner tratlsmission grid networks 300, or the like of
information for allowing the111 to perform an operation being required based upon the
determination via the communication part 140 and performs a remote operation ofthc electric
25 powcr distribution stations 200, the powcr trans~iiissio~grl id networks 300, or the like. For
example, the operatit~ge lectric po\\icr generatio11f acility determination part I20 notifies the
electric powvcr distribution stations 200, the po\\(er transmission grid networks 300, or the likc of
start/stop co~n~nanfdosr the electric power generation facilities, indication for output values,
instructions for switcliitig the net\\corks, and the like. The electric power generation facility
30 infornlation storage part 122 stores information on all oftlie electric power distributio~si tations
200 (all clectric power gctleration means) under the direction of the system. The information
stored it1 the electric power gei~emtion facility irifortnation storage part 122 irrcltrdes tlre
~naxi~iluo~ultlp ut capacity of each of the electric powcr generation facilities, values of power
generation outputs that cause low efticicncy and high elliciency (lo\v efficiency threshold and
high efficiency threshold), operating conditions (ONIOFF of the electric power generation
facilities), po\ver generation outputs, voltages, power factors, and frequencies of facilities being
operated, and the like. The electric power generation facility information storage part 122 also
stores infonnation on a start cost, a stop cost, and a running cost of each ofthe electric power
5 generation facilities as cost information. This infonnation may be held as start-operation cost
curve data indicating cost variations with time. This information may be stored as a ft~nction
having a variable of a fitel cost or the like. With this configuration, an actual cost of the fuel
cost during a power cut can be calculated, and comparison for selecting electric power
distribution stations 200 (electric power generation means) to be operated is facilitatcd. This
10 infonnation is trans~nittedt o the selection part 121 and used to detennine electric power
distribution stations 200 (electric power generation means) to be operated.
When the power supply from the conlnlercial po~vesru pply is interrupted, the power cut
status detection part 130 detects such a situation via the electric power distribution stations 200
and the com~nonicationp at? 140.
15 Furtliermore, \\'hen the commercial power supply is interrupted, the power cut status
detection part 130 acquires a necessary operation period (predicted power cut pcriod) during
which necessary electric po\\fer for demands is supplied through electric power generation within
the distributed electric power generation systenl 1 and notifies the operating electric poiver
generation facility determination part 120 (selection part 121) of the value. This necessary
20 operation period is first determined by an estimated period of time in which power supply from
the commercial power supply is rccovered. On the other liand, the necessary operation pcriod
nap be made shorter or longer depending upon the pcriod of time in which po\tler sopply is
recovered.
For the estinlatio~p~ro cess of the necessary opcration period, the power cut status
25 detection part 130 acquires infonnatioo on an clectric ponrer distribution time used as a basis for
identifying the necessary operation period before or i~nniediatelya fter a powver cut. The
information on an electric po\ver distribution time inay use information (power supply
interruption period information) defining a period of time during which power supply is
interrupted, which is used to calculate a period oftime required for power supply (necessary
30 operation period), or information (electric power distribution period infor~nation)d efining a
period of time to carry out electric po\ver distribution.
The polver supply interruption period information (predicted po\\Ier cut pcriod or
expected power cut pcriod) is received from an electric power cornpan): a human (administrator),
or the like. For example, the electric power distribution period information may bc received
from a database of past similar power cuts or human (administrator) other than an electric power
company.
For example, the information on the electric po\trer distribution time may be defined so
as to specify a time period in a day or lnay be defined so as to specify that power supply is
5 interrupted until a specific point of time (electric power is distributed fto~na specific point of
time). Furthermore, the itlformation on the electric power distribittion time may be defined so
as to specify a one-hour period fro111 the present time or the like.
111 preparation for a case where power s~~ppflroy1 11 the commercial power supply is
internopted for some reason, like a osual power cut, it is preferable for the ce~ltralizedc ontrol
10 station 100 to continuoosly acquire the status and de~nando f each of the electric po\trer
distribution stations 200 throt~gho bservation. It is also preferable for the centralized control
station 100 to have a database of demands varying with time (for exa~nplem, aximum
valucs/ave~.agev alues ill a day, a week, a yeat; or a season), calculate an estinlated value of
electric power being used (demand), and determine a rate of spare. Forthermorc, when a
15 different rate of spare is set for each of the systems (each group of consuniers), a desired degree
of stability can be achieved at a lo\\cer cost. Furthermore, pre-collection and use of a database
of demands required upon a polver cut (for example, maximum values/averagc values in a day, a
week, a year, or a season) is cticctive in calcolating an estimation value (prediction value) oftlie
required amount of electric power generation. On tlle other hand, electric po\\Ier demands
20 immediately after a power cut can be estirllated based upon electric power demands ilnnlediately
before the power cut. l'hercfore, the estimation value (nay be calculated by simply adding a
rate of changing demands.
The operating electric power generation facility determination part 120 (selection part
121) imtl~cdiatclyi dentifies a po\\Ier cut state and calculates a required amount of electric power
25 gcncratio~fi or each de~na~lloda d. Wit11 respect to the electric power distribu[ion statio~ls2 00
(electric po\ver generation means) that can generate a calc~~latcadm ount of po\trcr eficicntly, the
operating electric power generation facility determination part I20 (selection part 12 1) performs
a derivation proccss of a combit~ationo f the electric power distribution statio~ls2 00 that allows
the calcolated necessary operation period to fall within a desired range of a fuel cost or a cost
30 rate and selects electric po\Irer distribution stations 200. At that titne, according to start costs,
stop costs, and ronning costs of individual electric power distribution stations 200 (individual
electric power generation means), one or a required number of electric power distribution
stations 200 (clcctric power generation means) that can reduce tlle total runnit~gc ost during the
po\\er supply interrliption period is derived for the selection process. In the selection process
of the present e~nbodi~nenat ,m inimom nomber of electric po\Tfer generation facilities that can
cover the amount of po\ver supply demand within a ccl-tain range of efficiency can be selected.
Next, an operation of the centralized control statio~i 100 whell po\ver supply from the
commercial power supply is interropted for a sudden reason caused by troubles of high-voltage
5 transmission lines or the like will be described as a more specific example.
With the current electric power systems, when power supply ftom an electric power
company is interropted for some reason, a company or a facility manually or automatically
activates its electric power generation facility as an emergency electric l~o\\~seoru rce. Thos,
each of consomers generates electric power and covers its requiring electric po\tiel:
10 Fullhermore, a plurality of buildings of a colnpan): a university, or the like shares an e~nergency
electric power generation facility in some cases.
On the other hand, in the distributed electric power generation system 1, the centralized
control station 100 manages operations of the electric power generation means arranged in a
distributed manner as described above.
15 Fig. 3 is a flow chart explanato~yo f an operation example of the centralized control
apparatus 100 in a case where the centralized control apparatus 100 detects a po\trer cot.
First, the centralized control apparatus 100 (po\ver cut status detection part 130) detects
a place \\$here a power cut has been detected, i.e., electric power distribution station 200 to \\lhich
po\lrer s~tpplpis interrupted (F 101). In most of ust~alc ases of a wide-area power cut, power
20 supply to a plurality of electric power distribution stations 200 is simoltaneoosly interrupted.
On the other hand, in a case of troubles of transmission syste~nse, lectric po\ver distribotion
stations 200 to which po\ver supply has been interropted are limited. Therefore, when a power
cut occurs in only one electric power distribution station 200, it can be doubted that a local
accident causes the ponrer cut. The centralized control apparatus 100 may dircctly dctcct the
25 status of the commercial power supply to ino~litora power cut. Furthermore, in a case of a
rotational it~terruptioti system, clcctric power distribution to any area specified by a power
coinpany is intcrruptcd. Thus, electric power to some electric power distribution stations 200 is
intcr1.11ptedw hile electric power to other electric power distribution stations 200 is not
interrupted.
30 Next, the power cut status detection part 130 acquires electric power dcmands required
for each or all of the electric power distribution stations 200 via the electric pourer demand
monitor part 1 I0 of the centralized control station 100 (F102). At that time, a predicted power
cut pcriod (necessary operatiol~p eriod) is determined from the type ofthe power cot (F103).
For example, \\'hen an electric power conipany or the like has announced a power supply
interruption plan, a predicted (expected) power cut period (necessary operation period) is
acquired from tlie plan. Tlie power cut period may be determined by prediction from a past
history, prediction based opon information from other areas within the sanie jurisdiction, or the
like. Tlie infomiation on electric power distribution is used for a startlstop plan (selection
5 process) of the electric power generation facilities.
Then the operating electric power generation facility determination part 120 determines
operating electric power generation facilities for demand loads under the direction of the system
with respect to electric power distribution stations (electric power generation facilities) for which
power cut periods (necessary operation period) deterniined in F103, are not greater than a
10 predetermined tl~resliold(F 104). If a plurality of electric power generation facilities are
provided for one electric power distribution station (e.g., the electric power distribution station
200B), the aforementioned process [nay be performed wliile individual electric power generation
facilities are regarded as electric power distribution stations. This also holds true for the
following embodiments.
15 Here, an arithmetic processing example of determining electric power generation
facilities to be operated will be described with diesel generators, which are typical electric power
generation facilities of many electric power generation means. The following description
illustrates a scheme in which the centralized control station 100 detercnines wl~etheor r not an
existing emergency power source facility (diesel generator) installed in an electric power
20 distribtltion station 200 is energized upon a power cut.
Wlicn the diesel generator starts and stops, it requires file1 three times to five times fuel
required for a rated operation or even more. Therefore, fro111 the viewpoint of the cost, it
sliould be avoided to frequently turn on and off a generator because of a short-term ponfer cut.
In the follo\\~ingd escription, the unit of the operating cost is represented by the Japanese
25 cltr~ct~cuyni t [Yen]. The t~niot f t l ~ eop erating cost [nay etnploy aiiy reference unit, s~iclai s a
local currency unit, in a desired inalinel:
The threshold (T [minutes]) of the power cut pcriod is calculated from comparison of
tl~efi le1 cost [Yen] at tlie time of the start. For example, it is assumed tliat the fuel cost at the
time of a nonnal operation to output a desired electric po\\?er is 10 Yenlminute. If a required
30 outpot per minute at tliat time of the start beco~nesf ivc times, the file1 cost at the time of the start
can be calculated as 50 Yedminote. Therefore, assuming tliat a period of time fro111 tlie start
until a nortnal operating state (start time) is five minutes, the file1 cost required for the start is
250 Yen.
At tliat ti~nea, ssuming that the power cut period is 1 [tiiiootes], tlie operating fuel cost
during the power cut period is 10t [Yen]. The operating period for which the start cost and the
operation cost are equal to each other is t = 25 minutes.
Then the operating electric powver generation facility detern~inationp art 120 determines
to supply electric power through other electric po\trer generators and not to start this diesel
5 generator if the po\wrer cut period threshold Tis equal to or less than 25 minutes. The threshold
Tis variable according to the user's demand. For example, if the start cost needs to be 50% of
the operation cost or less, the start cost should be reduced to 10f x 0.5 or less. In this example,
the power cut threshold is 50 minutes. Thus, the threshold Tcan be varied in any way.
When the power cut period is long or \\,hen the amount of denland is larger than a
10 predetermined threshold, the operating electric power generation facility determination part 120
deter~ninesto operate power generators installed in an electric power distribution station
connected directly to each of power loads as witll the nornial operation of the existing emergency
po\\rer source facility.
Forthemore, even if the power cut period is equal to or shorter than the power cut
15 period threshold, the operating electric power generation facility determination part 120
determines to supply electric po\trer through one (or a few) electric power generation facilities
for a plurality of power loads when the total detnand is equal to or smaller than a threshold of
demands that can be covered by one (or a few) power generators.
Fig. 4 is a flow chart for determining electric power generation facilities to be operated
20 for po\tfer loads under the direction of an electric power distribution station having a powwrcr cut
period that is equal to or shol.ter than the power cut period threshold. In this example, the
operation is described as an internal processing of the centralized control station 100. Howevct;
this operation nlay be perfor~ned in a distributed manner in each of the electric po\vcr
distribution stations 200 or the consumers.
25 The start timing of a power cut may differ h t n one electric power distribution station
to another by several seconds to several minutes. In soch a case, the titning may be adjusted so
as to await the start of a power cut of another electric power distribution stations to conform to
the system. Furthern~orei,n response to the start of a power cut ofeach of the electric power
distribution stations, a demand load that needs power distribution may be detected each time.
30 Some electric power distribution stations may suffer fium a power cut while other tnay not.
According to the present invention, even in such a case, electric power generation facilities in
electric power distribution stations that do not suffer from a power cut are operated so as to
achieve a lower cost.
First, the power cut status detection part 130 detects demand loads to wl~ichp ower
supply is interrupted due to a power cut and an electric power distribution period (power cut
period) in an infortnation acquisition step (F201). Nest, the electric power demand ~uonitor
part 110 calculates tlie total electric polver demand (S) to be used by the detected demand loads
in the information acquisition step (F202). The total electric pourer de~na~(tSd) is the amount
5 of demand of all demand loads within a predetermined grid at tliat time \vhen external power
supply is interrupted to all ofthe electric power distribution stations 200. On the otlier hand,
when only part ofthe electric power distribution stations 200 suffers from a power cut, the total
electric po\\Ier demand (S) is tlie amount of demand of demand loads to which electric po\ver is
transmitted fi.0111 tliose electric power distribution statiotis 200 at tliat time. Furthermore, if
10 delilands or equipment limitations can be recovered by switching the power transmission grid
networks 300 from other electric power distribution stations 200, then such a method may be
used preferentially. The total electric power detiiand (S) [nay be managed with separated units
oftime. Furthermore, it is preferable to consider an expected amount of change during an
estinlated power cut period, in addition to the total electric power demand at tlie present time.
15 Particularly, a ~iiaxitnumd emand during an estimated power cut period should be considered.
Next, the operating electric power generation facility determination part 120 seeks for
one electric power generation facility tliat can meet tlie total electric power demand (S)
calculated within a predetermined output range from the electric power generatioti facility
infon~latios~tio rage part 122 (F203).
20 Here, the predetermined output ratlge refers to an output range in which an operating
cost such as a fuel cost of an electric power generation facility is lower than a threshold (cost
threshold) and has a minimum value of Pmi11 and a maximum value of Pmas. This range varies
depending upon tlie electric power generation facilities. Generally, when an output of a diesel
generator is lo\vered, a fuel efficiency is also lo\vered. For example, when the a~liounot f fuel
25 cot~s~itnptioant a rated output is L [littei~s/liour]p cr I kwh, t11c a~iiounto f fuel consumption at an
output of 50 % to I00 % is 1.0 - 1 .05 x L [litters/liour] per unit kwh. Ho\\revel; when tlie
output falls below 50 %, the amount of file1 required per unit kwh increases to 1.2 L
[litters/hour]. When the output falls below as low as 30 %, the amount of fuel required per unit
kW11 increases to 2.0 L [litters/hour]. An increased amount of fuel consumption leads to an
30 increased fuel cost. A cost curve based upon a starting cost and a running cost of an individual
electric power generation facility also varies depending upon the type of the electric power
generation facility and the temperature. Therefore, a cost curve may be obtained beforehand or
acct~mulated by data collection during the operation.
The minimum value is set in consideration of tliose facts. In an exatllple of a diesel
electric po\ver gencratiotl facility having the aforementioned characteristics, Pmin may be set to
be 50 %. With regard to the maximum value Pmax, it is important to consider all excess
amount of electric power generation (rate of spare) in the case where the amount of electric
power being demanded soddenly increases, apart from the fuel cost, in order to set Pmas.
5 Forthernlore, \\it11 regard to the power cut period threshold, more accurate cost
calculation can be made by considering a fitel cost curve obtained by an output ofan electric
power generation facility in order to set the threshold.
In the foregoing description, a powver cut period threshold is deternlined on the
assumption that an output of a power generator is 100 %. Howcvet; \\'lien an output of a power
10 generator is taken into account, a threshold during a power cut period may change. In thc
above example, the po\~ecru t period threshold Tis 25 minutes. In a case where a demand load
is 30 %, the amount of f~terle quired doubles. Accordingl>: the operating electric power
generation facility determination part 120 determines that the power cut threshold is 12.5
minutes. In other words, the operating electric power generation facility determination pal? 120
15 sets the threshold as a solution derived from considerations ofthe total electric power and the
demand rate.
When an electric power generation facility that can meet such conditions can be set, the
operating electric po\ver generation facility determination part 120 determines that electric power
generation facility as an electric power generation facility to be operated (F206). If a plurality
20 of elcctric potver generation facilities meet such conditions, the operating electric power
generation facility detennination part 120 may make a determination so as to disperse the
tlo~nbcor f operations or the operation periods by changing electric power generation facilities
wit11 reference to the operation history in order to avoid a concentrated operation. Alternatively,
the opetxting electric power generation facility deternlination part 120 ntay select a combination
25 that mininiizcs a fiicl cfficicncy, i.c., a file1 cost. There are two load conditions tliat take No at
F203. One is a load condition in which one electric po\ver generation facility cannot cover
because the total electric power demand (S) is too large. The other is a load condition Ell \vhich
the total electric power demand (S) is too small to meet an appropriate output range of any
electric power generating apparatus. In this case, the operating electric power generation
30 facility dcterlnination part 120 compares the total electric power demand (S) \vith P~nitlo f an
electric power generating apparatus having the lowcst ootput to determine whether the total
electric power demand (S) is smaller than Pmin (F205). As a result, if the total electric power
demand (S) is smaller than Pmin, the operating electric power generation facility determination
part 120 determines that an electric power generation facility having the lowest output tliat can
18
achieve the highest cost efficiency is to be operated (F207). If information indicative of the
outpot-file1 cost can be obtained, the operating electric power generation facility determination
part 120 can select an electric power generation facility I~avingth e highest cost efficiency rather
than selecting an electric pourer generation facility having the lowest outpot. On the other hand,
5 ifthe determination at F205 sho\\~sN o, the total electric powcr demand (S) is too large.
Therefore, tlle operating electric powcr generation facility determination part 120 increases the
number of electric power generation facilities to be operated (F204), and the deternlination
process of F203 is performed again witll a combination of those electric power generation
facilities. This process is properly repeated to set the number of electric power generation
10 facilities so as to cover the demands. The aforementioned flow may be changed appropriately
accordit~gto the characteristics of the electric power generation facilities.
After one or more electric power generation facilities to be operated have been
determined, the selection part 121 ofthe operating electric poiver generation facility
determination part 120 sends an operation conlnland to an ad~tlinistratoro fthe electric power
15 generation facilities (equipment of the electric power distribution stations 200) to be operated or
the electric power distribution stations 200 via the communication palt 140. Furthermore, a
remote operation co~ntnando r a switching comrnand is sent to switch the power transmission
grid networks 300 to connect the selected electric power distribution stations to thc respective
demand loads.
20 The foregoing description does not consider any electric power generation facility
(batte~yfa cilit): solar po\ver generation facility, or the like) that consumes no f~~clT. he
determination process may be configorcd to manage electric power generation facilities that
consume no fuel in parallel to the aforementioned electric power generation facilities that
consume fuel.
25 Furthermore, tlic dcternlination process may be configt~reds ~icltll iat, after electric
power generation facilities start to be operated, electric po\ver generation facilities of other
electric power distribution slations are switched into a load inode (for example, battery facilities
are switclled into a charge mode) so as to conforn~w ith a cost curve of the electric po\\'er
generation facilities being operated and are managed as demand loads. Additionall>: in order to
30 suppress the current, the electric power generation facilities may be set into a load mode, or
battery facilities may be set into a charge mode.
Thus, clcctric po\ver generation facilities to be operated are selected by the centralized
control station 100. Accordingly, the file1 cost can be suppressed against load variations after
the determination of the electric power generation facilities to be operated. Fu~thermore,
improvement of po\ver factors and regulation of demands can be achieved so that the file1 cost is
further reduced.
Forthermore, the centralized control station 100 may calculate, as a consu~nptionc ost, a
power transmission loss caused by power distribution interchange between electric power
5 distribution stations and add it to the aforementioned fuel cost.
Furthermore, the centralized control station 100 may hold start-operation cost curve
data indicating cost variations of individual electric power distribution stations 200 (electric
power generation facilities) with time beforehand, colnpare the star-operatio11 cost curves of the
individual electric power distribution stations 200 witli each other, and select electric power
10 distribution stations to be operated depending upon the elapse of time.
Moreover, when the demands greatly vary during the power cut period arid deviate from
a range in \vhich the outputs of the electric power generation facilities being operated are at a
high efficiency level, the centralized control station 100 may change the electric po\trer
generation facilities being operated. At that time, the electric power generation facilities being
15 operated may be changed so that tlie total cost is improved in consideration of the start cost and
the stop cost.
For example, it is assumed that tlie demand decreases fio111 500 kW to I00 kW with
time. In this case, if the operating electric power generation facility determination part 120
determines that po\trer generators having a given output range from 300 kW to 700 kW are
20 electric po\ver generation facilities to be operated, then the present demand (500 kW) is between
high-efficiency thresholds (Pmax and Pmin). Howeve!; if a ponler generator having a rated
output of 500 kW is continuol~slyu sed \vllile the de~nandd ecreases to 100 kW witli time, then
the outpt~bt ecomes 20 %. As a result, tlic demand falls out of the l~igli-efficiencyr ange (equal
to or less than I'inin). Therefore, \\'hen the operating electric power generation facility
25 determination part 120 detects that the demand has inoved out of tlie high-efficiency threshold
range of the electric potver generation facilities being operated (equal to or less than P~nin)i,t
performs a resetting process ofthe electric power generation facilities to be operated. This
resetting process ofthe electric power generation facilities to be operated can improvc the total
cost in consideration ofthe start cost and the stop cost. As a result, when the po\trer cut period
30 is so long that a wasting cost is greater that1 a cost ~zlatingto the start and stop of the electric
power generation facilities, the po\aler generators being operated are changed, for exatnple, from
a power generator l~avinga rated output of 500 kW to a power generator l~avinga rated output of
200 kW or less. This also holds true for not only a case of one po\ver generator being operated,
but also a case of a plurality of power generators being operated. Similarly, hen the operating
elcctric potver generation facility determination part 120 detects that the demand has moved out
of the high-efficiency tl~resl~olrdan ge of the electric power generation facilities being operated
(equal to or more than Pmax), it performs a resetting process of the elcctric power generation
facilities being operated. As a result, even \\then the demand increases from 500 kW to I000
5 kW with time, electric power generation facilities being operated are determined so that the total
cost is rcdt~eed in consideration of the start and stop cost. Similarly, when the demand
decreases with time and becomes equal to or less than the high-efticiency threshold range (Plnin),
a resetting process of the electric power generation facilities being operated is performed so that
the total cost is reduced in consideration ofthe start and stop cost.
10 In Enlbodinlent 1, if the total power load cannot be covered by one power generatol; a
parallel operation is performed with a plurality of po\vergenerators. In the parallel operation,
the operating electric power generation facility determination part 120 derives a system
configuration in \\~hieha plurality of power generators are connected to the power transmission
grid network 300 (300A or 300B) and operates the power generators and various types of
15 switches at inanaged timing. Therefore, the start of operation of the power generators is
synchronized sc1c11 that the start of operation of the power generators and the connection of the
power generators to the power transmission grid network 300 are carried out one by one.
Fui-thermore, the connection of the power loads to the power transmission grid nehvork 300 is
carried out one by one so that tl~ee lectric power quality is not degraded. In this mannel; the
20 operating electric power generation facility determination part 120 determines balanced control
behveen the generated electric power and the demand connected to the power transmission grid
network 300 \\lit11 reference to a cost of fuel that is actually consumed by the diesel generators.
According to the present embodiment, demands connected to a distributed electric
po\ver generation systenl 1 can be covered at a lower cost \\lit11 respect to a currency tinit by a
25 minimum number of electric po\\?er distribution stations 200 (electric po\ver generatio11 facilities)
being operated. Tllis efficient operation of electric po\ver generation facilities allows overhead
costs, for example, costs relating to turning on and oft'the poivcr generators, to be reduced.
Therefore, tlle running cost can be reduced.
[E~nbodiment2 1
30 In the present embodiment, when a power cut is dctccted by the distributed electric
power generation system, a plan to determine ho\v to sk~pplye lectric power to power loads
connected in a ust~als tate is determined in eacll ofthe electric power distribution stations.
Tllerefore, a distributed control station including the aforementioned centralized control station
100 is provided in all or some of the clectric power distributio~s~ta tions 200.
The following deterinination process is performed by the selectio~ip art 121 ofthe
operating electric power generation facility determinatio~ip al t 120.
Fig. 5 is a flow chart explatlatory of an operation example of the operating electric
power generation facility detennination part 120 in a case \vIiere a power cut is detected it1
5 Enibodiment 2.
The operating electric power generation facility detennination part 120 detects a power
cut (F301), then identifies an electric power demand (F302), identifies a p~cdicted power cot
period (F303), and deteniiines \vhetlier or not tlie power cut period is equal to or shorter tliatl a
tllreshold (F304). If the power cut period is equal to or shorter tlian the threshold, a selection
10 process of electric power generation facilities to be operated according to Embodiment 1 is
performed in its own electric power distribution station 200, unlike existing power supply from
an electric power generation facility installed ill its own electric power distribution station 200 or
another electric power distribution station 200 (i.e., supply under the direction of its own station).
This selection process determines that the electric po\ver genelation facilities of its o\vn
15 electric power distribution station 200 are selected as electric power generation facilities for
supplying electric po\ver to the deliland loads so that its own station covers tlie demands, or that
the station receives electric power supply from another electric power distribution station 200 to
cover the demands.
Even if the power cut threshold is eqiral to or greater than the threshold, in a case where
20 it is determined that tlie electric power de~nando fthe demand loads to which electric power is
being supplied is eqoal to or lower than tlie predetermined tlireshold (Pmin) of the electric power
generation facilities of its own electric power distribution station 200 (F305), receiving electric
powcr h m an electric power generation facility of another electric power distribution station
200 is selected. In otlier\\~ordsi,f tile deinand is less tlian Pmin, the operating electric power
25 generatio11f acility deterinination part 120 s~~pplielse ctric po\vcr to the demand loads not fiom
an electric power generation facility of its o~\~stnat ion, but fio111 an electric power generation
facility of another station. If the demand is greater than Pmin, the operating eiectric power
generation facility determination part 120 supplies electric power to the demand loads from an
electric power generation facility of its o\vn station (F306).
30 Operations after the determination of electric power generation facilities to be operated
(F307) are the same as those of Embodiment 1. At tllat time, various kinds of notifications are
sent to other cooperating distributed control stations.
According to Embodiment 2, electric power supply fro111 an electric power generation
facility of another electric power distribution statio~ii s selected based upon the power cut period
and the electric power de~nandf,o r exatnplc, when the electric po\trer denland is small even in a
case of a long-term power cut. With this configuration, a running cost such as a fuel cost at the
beginning of the operation and during the operation can be reduced.
[Embodiment 31
5 In the present embodiment, there will be described a nletllod of detecting a power cut in
a distributed electric power generation system and, when two or more electric power generation
facilities are to be operated among three or more electric power generation facilities, switching
power transmission grid networks into an operation mode that assumes individual single
operations in each of the stations. When a plurality of electric power generation facilities are to
10 be connected, a grid arrange~nent( nay be designed in which all of the loads are connected to a
single large grid while the electric power generation facilities are operated in parallel. If the
system includes, as an electric po~\~gcern eration facility, a rotation type power generator such as
a diesel generatot; it is difficult to perfom] a parallel operation while maintaining the phase or
power factor in a satisfactory manner. Furthermore, if the types, the manufacturers, the
15 capacities, and the like of the electric power generation facilities are different, the degree of
difliculty increases. Therefore, when the demand is covered by a plurality of electric powve~
generation facilities being operated, a determination is made such that the total demand load is
divided into the same number of groups as the electric power generation facilities being operated.
Thus, the systenl is configured such that each of the electric power generation facilities supplies
20 electric power to one group. Division and coupling of the groups tnay be achieved by using a
group of switches in the power transmission grid nehvork 300 between the electric power
distribution stations and controlling the group of s\vitcl~es.
Fig. 6 is a system configt~ration diagram showing a distributed clcctric power gencration
systenl si~nplifiedto explain operations according to the present embodiment. 'The electric
25 power distributioll stations 200 and the demand loads (1-4) ale paired as a small grid
configoration for a usual operation (when electric power is received from the commercial power
syste~n). The follo\\ling description assumes three sinail grids (in wllich the demand loads 3
and 4 foml one small group beforehand), Switches (such as a relay and a breaker; denoted by
SW12 and SW23 in Fig. 6) are provided between the sillall grids. The rated outputs of the
30 electric power generation facilities are 100 kW, 200 kW, and 300 kW, respectively. If the
electric power distribution stations 200 are connected to each other at a plurality of points, the
power transmission grid network 300 may be tnanipulated such that all of the related switclies
are operated when the electric po\ver distribution stations 200 are disconnected from each other.
In this example, an operating electric power generation facility determination part 120 is
provided ill the centralized control station 100 as with Embodiment 1. The distributed electric
power generation system may be controlled by the electric po\ver distribution stations 200 as
with Embodiment 2. This also holds true for the subseqoetlt embodiments.
Fig. 7 is a flow c11a1-t sho\\ting an example operation of determining a systenl
5 configuration for a group of po\ver loads in Embodiment 3, i.e., an exa~upleo peration oftlie
afore~nentioncdd eterniination process of tortling on and off the electric power generation
facilities 1-3 and a group of switches.
Futlhern~ore,F ig. SA is a diagrani illustrating the amount of detnand in each of the
demand loads. Fig. 8B is an explanatory diagram illustrating a systenl configaration in a case
10 where pairs of the electric po\ver generation facilities being operated and groups of the demand
loads are derived.
When the operating electric power generation facility deternlination part 120 receives a
power cut start notification from the power cut status detection part 130, it identifies tlie atnount
of demand in each of the loads from the electric power demand monitor part 110 (F401 and
15 F402). As shown in Fig. 8A, the amounts of detnand in tlie loads are 90 kW, 70 kW, and 150
kW, respectively. Therefore, tlie total electric po\ver demand (S) is detected to be 3 10 kW.
Next, the operating electric power generation facility determination part 120 seeks for
one electric power generation facility that can meet the total electric po\tler denland (F403). In
this example, ho\vever, the maximum rated output is 300 kW. Tllos, no electric power
20 generation facility n~eetsth e conditions (proceeding to No at F403).
Therefore, the operating electric power generation facility determination part 120
increase the number of electric po\ver genelation facilities that meet the total dcmand load by
one (F404). Then the operating electric po\ver generation facility determination part 120 seeks
again for a combination of two electric po\frer generation facilities that can meet the total dcmand
25 load (F403).
The fact that hvo electric power generation facilities meet tlie demands at three points
means that the power transn~issiong rid net\vorks 300 (tliree slnall grids) are grouped into t\\:o
small grids. As shown in Fig. SB, two grid groups can be produced by turning one of the
switches SW12 and SW23 on and turning tlie other off.
30 To generalize this, ~vhen17 electric po\xrer generation facilities are grouped into rrr small
grids, , , [C,,,_ I combinations of openedlclosed switches are possible.
In the prescnt embodiment, when three electric 11o\\~egr eneration facilities are grouped
into two small grids, ~ C=I 2 . A first conibination is a case where the switch SW21 is opened
while tlie switch SW23 is closed. In tliis case, the electric po\xrer generation facility I covers
one group, and the electric power generation facilities 2 and 3 cover one group. A second
contbination is a case where the switch SW21 is closed \vllile the switch SW23 is opened. In
this case, the electric power generation facilities 1 and 2 cover one group, and the electric power
generation facility 3 covers one group. As shown in Fig. SB, the onloff conditions of tlte
5 switches determine the on/oKconditions of the electric power generation facilities.
The operating electric power generation facility determination part 120 assigns a load to
an electric power generation facility to be tamed on and excludes any combination (system
configuration) that exceeds a rated capacity of an electric po~verg eneration facility fiom the
options. For example, in the combination I, the electric pouler generator facility 2 has a rated
10 capacity of 200 kW and cannot cover a demand of 220 kW in total. Therefore, this setting (tlte
setting of operating the electric po\Xier generator facility 2) is excluded from tile options. The
cotnbination 2 is also subjected to the seeking process. Thus, possible contbinations are limited.
Next, the operating electric po\\'er generation facility determination part 120 calculates
a file1 cost of each of all combi~latiot~osf electric power generation facilities that meet the
15 electric power demand and selects a combination that achieves the mini~uumc ost as a
combination of electric power generation facilities to be operated (F405). In the example
illustrated in Fig. SB, the co~nbinations 1 and 2 are compared to each other, and the combinatiotl
1, which costs less, is selected. The process of calculating the ininimum cost may include
calculating a start cost, a stop cost, and a running cost of an electric power generation facility to
20 be operated and a cost following tile amount of demand of a group of demand loads with respect
to an electric power distribution period for each of combinations, and selecting a case having the
smallest value.
Next, the operating electric pouter generation facility determination part 120 determines
a connection configuratio~l of tlle po\trer transmission grid netwol.ks 300 that can implement a
25 pair of tltc dcrivcd clcctric power gcneratio~l facilities to be operated and a group of deinand
loads (F406). The connectiot~c onfiguration ofthe power trans~nissiong rid networks 300 tilay
be obtained as a combination that inects a power transmission sorplus in considcl-ation of the
physical connection system of the electric power generation facilities to be operated and the
delnartd loads. At that time, tlle electric power generation facilities to be operated are separated
30 into different systems. Specifically, the connection configoration ofthe power transmission
grid networks 300 is determined such that each of the electric po\lrer generation facilities covers
tlte paired demands with a single operation.
In this Inannet; with tlle operation rule to litnit an operation of each of tlte clectric power
generation facilities to a single operation, a configuration of the power transmission grid
networks is derived like opening and closing switches between grids in the illustrated example.
Thus, there can properly be provided a system configuration that can further reduce a cost such
as a fuel cost.
[Embodiment 41
5 In Embodiment 3, tlie number ofelectric power generation facilities is increased by one
at a time to obtain the niinimutii number of electric power generation facilities tliat can cover the
power load. Fortlierniore, a coiiibinatio~it hat minimizes a f k l cost is selected fro111 among
configurations of tlie power transmission grid nehvorks in which each ofthe electric power
generation facilities perfonns a single operation.
10 Meanwhile, the cost may be low even with many electric po\trer generators. For
example, in sollie cases, three electric po~verg enerators can cover tlie demand at a loxver fuel
cost than ttvo electric power generators can. For example, it is assumed that the control station
determines that hvo electric power generators cover a power load of 1100 kW in total. When
tlie least costly combination is a combination of a 650-kW electric power generator that covers
15 650 kW and a 1000-kW electric po\frer generator that covers 450 kW, the output of the 1000-kW
electric power generator falls below 50 %of its rated capacity, thereby lowering tlie power
generation efficiency. Howevel; if three electric power generators are allo\ved to cover the load,
each of two 300-kW electric po\ver generators can cover a load of 225 kW, so that the load of
450 kW, \vliich is covered by tlie 1000-kW electric po~verg enerator; can be covered by tlie two
20 300-kW electric power generators. Tlie electric power generation output exceeds 75 %. Tlius,
the total fuel cost can also be reduced.
Tliercforc, in the present embodiment, fbel costs are calculated for all combinations of
configuration of one or more electric powcr gcneration facilities and power transniission grid
net\\~orkstl iat can cover all demands irrespective of the number orelcclric power generation
25 facilities (conibinations of s\vitclies turned on and ofi-or tlie like). Tlie lcast costly cornbinatio~i
is selected fro111 among those calculated results. Tlie explanation of portions similar to those in
tlie aforementioned embodiments \vili be oniitted.
In tlic present embodiment, there will be described an esatnple of an operation of
selecting electric power generators (group) for 24 hours as enielgency electric po\ver distribution
30 stations (electric power generation facilities) based upon prediction (estimated value) of electric
po\\(er demands of tlie nest day on the previous day. I-Io\\~evela; s witli Embodiments 1-3, the
control station ma)' perfomi a similar selection operation at the timing of a start of a power cut.
Furthermore, a schedule of a systeni configuration of a provisional operation for a power cut for
all 24 hours may be detemiined based upon tlie amount of power supply demand that has been
predicted on the previous day. A schedule of a system config~trationo f an operation for a
power cut ]nay be recalculated from a difference between a mcasured value of the demands on
that day and the prediction. Then setting of a system configoration that will actt~allyb e
constrt~cteda t the time of a power cut may be updated.
5 Fig. 9 is a flow chart showing an example operation of determining a system
configuration for a group of power loads according to the present embodiment. Fig. 10 is an
explanatory diagram showing schedule table information illustrating a determined systetn
configuration for each unit of tinie. Fig. 11 is an explanatory diagram showing demand
prediction table infortnation illustrating a list of electric power demand predictions that is used to
10 determine a systetn configuration for each litlit of time.
A procedure will be described \\fit11 reference to the flo\\c chart of Fig. 9. It is assi~rned
that the electric power generation facilities 1-3 to be operated include three electric power
generation facilities GI, G2, and G3, which have a rated oc~tpuot f I00 kW, 200 kW, and 300 kW,
respectively (as with Fig. 6). The denland loads are divided into small groups LI-L3.
15 This procedure illustrated in the flow cl~arpt rodoces a schedule table as sllown in Fig.
10 (referred to as a UC table). The electric powver generation facilities and on-off states of
switches in the electric power networks are represented by "0" and "I" for each of time fratnes.
For the electric power generation facilities, " I " means an on-state (operated), and "0" tneans an
off-state (stopped). For the switches, " I " means an on-state (closed), and "0" means an off-
20 state (opened).
As sho\vn in Fig. 11, the operating electric power generation facility deter~ninationp art
120 of the centralized control station 100 acquires a demand prediction of the total load for eacll
hour \vith respect to the groups LI-L3 from the electric power demand monitor part 120 (F401).
As a matter of course, a demand prediction niay be collected wit11 a shorter unit of time, and the
25 follo\ving operation may be performed with a sl~orteur nit of tin~e.
The operating electric po\t1er generation facility determination part 120 perfortns the
processes from F402 to F404 for every unit of tinie from one o'clock to 24 o'clock (F402 to
F405). Here, an example ofthe period between 7 o'clock and 8 o'clock \\till be described.
T11e number of cotnbinations in this system configuration is based ~ ~ p othne start and
30 stop of the three electric power generation facilities GI, G2, and G3 and the onloff states of the
t\vo switches SW12 and SW23. Tlle total lulmber of combinations is two to the fifth powet; i.e.,
32.
The operating electric power generation facility determination part 120 extracts
reasonable combinations (system configurations) that can be formed as a systenl from all of the
combinations in F402. The following two points can be considercd for this reasonabilitp
deter~nination. Fnrthem,ore, configurations that would be problematic to configure the systenl
are excluded. (For example, it is preferable to esclude a configuration that only includes
electric power generation facilities having poor follo\\~-upc apability or a configltration that only
5 includes electric power generation facilities having a large disturbance.)
A first consideration is a combination that docs not allow two or more electric power
generation facilities to be operated for one load group (small group). The present etnbodiment
adopts a system configuration that manages electric power generation facilities without a parallel
operation but with a single operation. Therefore, one electric power generation facility is
10 always operated in a group.
A second consideration is a condition that one or more electric power generation
facilities are operated to supply electric po\ver to each load when there is a denland (when a
demand load is more than 0 W).
Fig. 12 represents extracted results of possible system configurations based upon the
15 aforementioned operation rule it1 order to determine a system configuration for each lnlit of titne.
As shown in Fig. 12, a group of reasonable systenl configorations can be sliown by the
table information.
In the combination 1 showing a system confignration, the s\vitches SW12 and SW23 are
closed, and all demand loads and electric po\\cer generation facilities fort11 one group.
20 Forthermore, this combination is a configuration showing a system configuration in which the
electric po\\rer generation facility GI bears capacity of electric power generation collectively for
all of the loads.
In this combination I, at least one elcctric power generation facility for supplying
electric po\ver to each of the loads is operated, and the number of electric po\t8er generation
25 facilities being operatcd in each of the groups is one. Therefore, the co~nbination I is
detennined to be a reasonable combination based upon the operation rule.
On the other hand, the combination 2 is a confignt.ation in \\~l~itchle~ s witches SW 12
and SW23 are closed while three electric power generation facilities are operated. Furthermore,
this combination is a configuration in which all loads and the electric power generation facilities
30 form one electric power network. With this configttration, the electric power network includes
one group. As a result, three electric power generation facilities are operated in one group.
Accordingly, this combination can be determined to be a system configuration not having
reasonability.
Furthermore, the combination 4 is a system configoration in \vhich the demand load L1
to the electric po\I1er generation facility GI fornls one group, and in which the demand load L2
to the electric po\Irer generation facility G2 and the demand load L3 to the electric power
genelation facility G3 form one group. Thus, h o groups (small electric po~vern etworks) are
formed in total. 1-Iowevel; no electric po\trer generation facility is operated in each of the
5 nehvorks. Accordingly, this configuratiotl can be determined not to be reasonable.
In this mannel; the operating electric power generation facility determination part 120
deternlincs the reasonability for each of other combinations and picks up only reasonable
combinations from 32 combinations.
Next, the operating electric power generation facility determination part 120 assigns
10 values to the electric power generation facilities and the loads (groups) and calculates a cost of
each of the system configorations at F403. During this process, the operating electric power
generation facility detertnination part 120 excludes any combinations in which the value of the
load (demand of each of the groups) assigned to each ofthe electric po\ver generation facilities
subject to a single operation exceeds the value of the rated output of the electric power
15 generation facility. The operating electric power generation facility determination part 120 may
first narrow possible conlbinations by using the rated output and then calculate a cost of each of
the systeln configurations.
Further explanation is provided with reference to Fig. 13. Fig. 13 shows results of
selecting a combination that achieves a lower cost according to the amount of power supply
20 denland (predicted demaod) during the electric po\ver distribution period (the operating unit of
time) for each of the reasonable systeln configurations when a systcln configuration for each unit
of time is determined. The combination numbers of the systeln configurations in Fig. 12 accord
with thc combination numbers in Fig. 13. The system configurations in Fig. 13 only show
combinations that have been determined to be reasonable.
25 'flle combination 1 is a configuration in \vhich 3 10 kW is assigned to the electric po\trer
generation facility GI. Howvevel; 310 kW is mole than 100 kW, which is a rated output of the
electric ponrer generation facility GI. Accordingly, the cornbination 1 is excluded from the
possible combinations. The combinations 5 and 7 are similarly excluded from the possible
combinations.
30 In the combination 3, the demand load LI to the electric power generation facility G1,
the denland load L2 to the electric power generation facility G2, and the demand load L3 to the
electric power generation facility G3 fonu a small group of an electric power net\vork. A fuel
cost per unit of time is calculated to be 1500 Yen. Similarly, in the contbination 6, a fuel cost
per unit of time is calculated to be 1300 Yen. In the combination 8, a fuel cost per unit of time
is calculated to be 1200 Yen.
Then tile operating electric power generatio11 f acility deter~ninationp art 120 selects the
least costly combination (system configoration) fro111 among the possible combinations that have
not been excluded (F404).
5 In this example, as seen from Fig. 13, the combination 8 is selected as the least costly
combination. Specificaliy, the operating electric power generation facility deter~ninationp art
120 sets, as a less costly systeni co~tfigutntiont,h e value (1, 0,0, 1, I) of a co~nbil~atiofrol r the
period between 7 o'clock and 8 o'clock in tlie aforementioned example into the row of the
schedule table sl~own in Fig. 10 that corresponds to the period behveen 7 o'clock and 8 o'clock.
10 The operating electric power generation facility determination part 120 follows the
same flow fi.0111 F402 to F404 for other time periods and sets the schedule table. Thus, the UC
table shown in Fig. 10 is produced on tl~ep revious day and used for an emergency. When a
power cot occurs, the centralized contml station 100 reads a configoration of the current time
period that has been calculated as a low-cost system configuration from the UC table and sets the
15 electric power generation stations (electric po\ver generation facilities), the electric power
nehvork switches, and the like for operation. As a result, electric power can quickly be
distributed to consomers at a low cost upon a power cut.
In the present embodiment, only a fuel cost of electric power generation facilities being
operated for each unit oftinie is considered to select an optimum combination of the electric
20 power generation facilities and the electric power network configurations (onloff states of the
switches SW). Costs relating to the start and stop of the electric power generators and the Iikc
are not considered. However, the nurnber of onloff changes of each of the electric power
generation facilities or the s\vitches or fuel costs relating to the onloff changes may bc
considered as relevant para~l~elewrsh en time elapses over a plurality units of time. In other
25 words, doring a po\ver cut, a selection proccss of an optim~tm combination of a system
configuration for each unit oftime (nay include adding a cost caused by changes of the system
configuration. Further~nore,a shorter unit oi'timc than others may be set for a time period
during which electric power greatly varies.
[Embodiment 51
30 Fig. 14 is a system configoration diagram showing a distributed electric ponrer
generatiori systerrl acconlirlg to Embodiment 5. 111 the present embodiment, an operation of
l~re-seiecti~an~ gin expensive system configuration for each unit of time as illustrated in
Embodi~ncn4t will be described along with a configuration of a distributed electric power
generation system having a cornmoll bus illustrated in Fig. 14. In this system configuration, a
common bus is newly added. The common bus allows three electric power generation facilities
provided in the electric power distribution stations 200 to be connected to a demand load
connected to another electric po\tler distribution station.
When the centralized control station 100 detects a power cot, it turns the switch SWl-
5 SW3 on so as to connect the corresponding electric power distribution station to the common bus
and tor~t~hse switches SWI-SW3 off so as to inallage the corresponding electric power
distribution stations without connection to the common bus such that electric po\ver is supplied
from the electric power generation facility in the electric power distribution station connected to
its own load.
10 The follo\ving process is the satne as that described in Enibodiment 4. A system
configuration for emergency for each unit of titne may be pre-selected based upon the demand
prediction. Alternatively, a systcln configuration nlay be selected at the beginning of a power
cut.
Fig. 15 is a flow chart showing an exatnple operation of selecting a system
15 config~~ratiofrolr a groop of power loads. Fig. I6 shows schedule table information illustrating
a determined system configuration for each onit of time.
In the following description, there will be described at1 exatnple process of obtaining a
setting of the UC table on the previous day. It is assumed that the rated capacity of the three
electric power generation facilities GI-G3 connected to the demand loads 1-4 is 100 kW, 200 kW,
20 and 300 kW, respectively. Predicted values are used for denlands as with Fig. 11.
In the flo\v chart of Fig. 15, the procedure of F401 is the same as that described in
Embodiment 4. Specificallj: the operating electric po\ver generation facility determination part
120 acqc~iresa demand prediction for each unit oftime (F401) and then sequentially determines
an inexpensive system configuration for each unit of titne (F402-405).
25 111t l~cfo llo\\~it~dges criptioii, (lie steps F402-F405 will be described \\lit11 all cxaniple of
a setting for the period between 7 o'clock and 8 o'clock. In the present embodilnent, there are
three electric power generation facilities and three switcl~es. Therefole, the total number of
combinations is t\vo to the sixth po\\'er, i.e., 64.
When a system configuration is determined for each unit of time, the operating electric
30 power generation facility determination part 120 deterlnines the reasonability of each of the 64
system configurations for possible combinations based upon the operation rule and obtains the
results as shown in Fig. 17 (F402). A first criterion of the reasonability is that two or more
electric power generation facilities are not operated for one load. This is equivalent to the
condition of Elnbodiment 4 that two or more electric power generation facilities are not operated
within one electric power network. In this system, this criterion is set so as to perform a single
operation. For example, if a system for synchronizing tlte power generators with each other is
introduced in order to perform a parallel operation, this criterion may not necessarily be
considered. A secontl criterion is that one electric power generation facility is operated for one
5 load group. The onloff states oftlte s\\ritches and the electric power generation facilities are
determined such that any oftlte electric power generation facilities always supplies electric
power to a load group other than 0 W. This allows one electric power generation facility to
supply electric power to a plurality of loads (see demand loads 3 and 4).
An example of tlte reasonability determination table infomation indicative of
10 determination results of the reasonability as shown in Fig. 17 includes 10 colnbinatio~lsa mong
all combinations.
In the combination 1, only tlte electric power generation facility G 1 is operated, and the
common bus is used to supply electric po\tter to the power loads 1,2,3, and 4.
In tlte combination 2, all oftlte switches are turned on, and all of the electric power
15 generation facilities are turned on. Three power generators are operated. As a result, this
combination is determined to be excluded fiom tlte criterions of tlle present entboditnent.
The combination 3 is a combination for a usual operation. None of the electric po\ver
generation facilities is connected to tlte common bus. All of the electric power generation
facilities are operated to supply electric power to the demands being connected.
20 Furthermore, in the combination 4, the electric power generation facilities GI and G3
are connected to the common bus but are not operated. The loads connected to tlte electric
power generation facilities GI and G3 are not supplietl with electric power. This does not meet
tlte aforelnentioned criterions. Accordinglp, this combination is excluded.
Thus, the operating electric power generation facility determittation part 120 selects the
25 cotnbillations 1, 3, 5, 6, 7, 8, and 10 as systetn configurations determined to be reasonable
combinations fro111 among the possible systetn configurations (F402).
Next, tlle operating electric power generation facility determination part 120 assigns the
amount of power supply demand (predicted value) for the electric po\\(er distribution period (the
unit of time between 7 o'clock and 8 o'clock) to tlte selected combinations. respectively, and
30 calculates a file1 cost of each of the combinations (F403). As shown in Fig. I I, tlte electric
power demand behvcen 7 o'clock and 8 o'clock is 90 kW for tlte load I, 70 kW for the load 2,
and 150 kW for the loads 3 and 4 in total. When a fuel cost is calculated by assigning those
values to tlte remaining combinations in the table of Fig. 17, the data for selection tltat are
illustrated in the selection result table information ofFig. 18 can be obtained.
Then the operating elcctric power generation facility determination part 120 excludes
configorations that exceed a rated capacity of the electric power gelreration facilities, such as tlie
combinations 1, 5, and 6, fiom tlie reasonable system configurations and selects the least costly
combination fiom the remaining possible combinations. In this example, the combination in
5 which the electric power generation facility 2 (having a rated output of 200 kW) covers tlie
dcrnand load of 70 kW of the load 2 and tlie electric power getieration facility 3 (having a rated
output of 300 kW) covers the total demand load of 260 kW of tllc loads I, 3, and 4 has tlie lo~\~cst
cost of 1200 Yen. Specifically, this combination 10 is selected as a system configuration for a
time period behveen 7 o'clock and 8 o'clock.
10 In the politer transniission grid nchvork according to the present emboditnent,
li~nitationso n a co~ilbi~iatiomne thod of the demand loads and the clectric power generation
facilities are reduced. In Embodiment 4, the electric power generation facilities are connected
directly to each otllel: Therefore, only the clectric power generation facility of 200 kW and tlie
denland load 2 cannot be made independent, and an optimized configoration it1 \vhich the electric
15 ponrer generation facility of 300 kW is shared wit11 the detnand loads I, 3, and 4 cannot be
established. In contrast, with the configuration of the power transmission grid nehvork
according to the present embodiment, the aforementioned system configuration can be
established. Tlius, tlie namber of possible combinations to be liandlcd can be increased.
Accordingly, a system configaration that can fi~rthere ducc costs sucli as a file1 cost is expected
20 to be derived.
[Embodiment 61
Fig. 19 is a system configoration diagram showing a distributed electric power
generation system according to Embodiment 6. The present emboditnetit has a distributed
electric power generation system including two or inore electric power generation facilities in the
25 electric power distribtttion statio~isa tid also itlclutling a common bus.
In the present etnbodiment, t\vo electric po\\'er generation facilities are provided in the
electric po\\Ier distribution station 2. As with tlle configoratioti of E~iibodimen4t , thc elcctric
po\\Ier generation facilities are connected directly to each other. Furthermore, two electric
power generation facilities are colitiected to each other via another common bus in tlie electric
30 power distribution station 3.
In tlie present embodiment, electric power distribution between the electric power
distribution stations is achieved via the general common bus. As \\lit11 E~nbodimen4t , tlie
power transmission grid network tnay be configured such that tlie electric power distribution
stations are connected directly to each otlicl:
When eacli ofthe electric power distribution stations 200 being operated is connected to
the general cornmoll bus, it can be connected by closi~lgth e s\\~itcliS W1-SW3 so as to cany out
clcctric power distribution to the detnatid load assigncd via the common bus.
For example, even if all of the switches SWI-SW3 are opened, electric power
5 distribution can be carried out between the electric po\trer generation facilities in its o\vn electric
power distribution station with respect to the electric po\L1er distribution station 2 and the electric
power distribution station 3. For example, the electric power distribution stafion 2 includes a
I 00-kW electric power generation facility and a 200-kW electric power generation facility,
\\~hical~rc co~inectedt o the demand load 21 and the demand load 22, respectively. If the switcli
10 SW21 is opened, the demand load 21 is supplied with electric power fi'otn only the 100-kW
clcctric poitier generation facility. If the s\vitcli SW21 is closed, the deliland load 21 is supplied
\vitIi electric power not only from the 100-kW electric power generation facility but also ftoni
the 200-kW electric power generation facility. As a matter of course, both of the demand loads
21 and 22 map be supplied with electric power from the 200-kW electric power distribution
15 facility.
In the present embodiment, a system configuration for cach unit of tinie is determined
by centralized control. The flow chart of a process of determining a syste~ici onfigoration is the
same as that in Fig. 15. Fig. 20 illustrates a schedule table generated by this process.
Fig. 21 is an explanatory diagram showing reasonability determination table
20 information illustrating the results of deternli~iingth e reasonability as possible system
configurations based upon the operation rule when a systern configuration for eacli unit of time is
to be dcter~ni~ied.
The centralized control station 100 examines the reasonability of each of possible
combinations in the flo\v chart F402 with use of the reasonability determination table
25 i~ifor~iiatiosnh o\vn in Fig. 21 and extracts co~nbinationsth at tncet the reaso~labilitp.
Fig. 21 shows only a portion of the possible combinations. 111 the co~nbination 1, all of
the s\\4tclies SWI-SW3 are set to be 1. Thus, all of the electric power distribution stations are
connected to the common bus, and only the electric ponrer generatioti facility GI installed in the
electric power distribution station 1 is operated. In the combination 2, all oftlie electric power
30 distribution statio~isa re connected to the common bus. Two or more clcctric power generation
facilities GI, (321, and G3 1 are operated in one group. Therefore, this combination does not
meet the criterions for the reasonability. Thus, tliis combination is excluded. In tliis inannel;
the combinations 1, 2, 5, 7, 8, and 10 meet the criterion for the reasonability.
Next, in ordcr to obtain the selection result table information illustrated in Fig. 22, the
centralized control station 100 assigns the predicted amount of demand for each unit of time to
the electric power generation facilities being operated and calculates a cost of each of the
possible combinations (F403). Here, them \\rill be described an example in which the demand
loads 1,21,22,3, and 4 l~avea demand of 80 kW, 50 kW, 50 kW, 150 kW, and 100 kW,
5 respectively. The combination I is a setting in which the electric power generation facility GI
is required to have an output of 380 kW, which is tlie sum of all of the loads. Howevel; the
electric power gencration facility GI has a rated output of 100 kW. Thus, tlic required output
esceeds the capacity. In this maonel; the combinations 1 and 5 are excluded from the possible
options because the amount of demand does not tnatch the capacity of the electric power
10 generatio11 facilities in the combinations 1 and 5. The least costly combination oftbe remaining
combinations is the co~nbination8 . Only the electric power generation facility G3 I of the
electric power distribotion station 3 and the power load 31 are independently managed withoc~t
connection to tlic common bus. Other loads arc supplied with electric power from the 300-kW
electric power gencration facility.
15 According to the present ctnbodiment, a less costly combination can be selected if a
plurality of electric po\vcr generation facilitics are installed in an electric power distribution
facility.
As described above, according to tlle present invention, there can be provided a
distributed electric power gencration systelli that can rcduce a running cost of a low-ootpot
20 operation of electric power generation facilitics and a file1 cost relating to toroing on and offtlie
electric power generation facilitics by reducing the nomber of electric power generation facilitics
having lo\v cost efl'ectivencss, and a method of controlling such a distributed electric power
gcneration system.
In tlle existing distributed ponrer supply systcms, various kinds of operation control
25 tecl~~liqih~aevse been proposed to optimize tbc cncrgy efficiency lien electric power generating
apparatuses to bc operated are to be determined. Ho\vevel; wliethcr a powcr cut period of a
com~nerciapl o\ver s~~ppilsy l ong or short, electric power gcneration facilities are operated with a
low output so as to match t11c alnount of demand of each of po\ver loads. Therefore, a large
loss is caused to a fuel cost, for example, due to the start of the electric powcr gencration
30 facilities. Accordingly, in the distributed electric power gcneration system, when electric ponrer
generation facilities to bc operated for covering demands are selected upon a power cot of an
external powcr source, a period of the power cut and the amount of electric power generation
required during the po\vcr cot period are calculated. One or a required number of electric
po\ver ge~ierationf acilities that sc~pplye lectric power at a low cost are selected in a centralized or
distributed control station based upon a start and stop cost and a running cost of the individual
electric powcr generation facilities. Electric power is supplied fiom those electric powcr
generation facilities to the denlands. As a result, according to the present invention, a fuel cost
and the like can be reduced by regulating the number of electric po\lrer generation facilities being
5 operated during a power cut period, during which an operation period of the electric power
generation facilities greatly affects the electric power generation cost. Furthernlorc, there can
be provided an operation of obtaining a less costly combination based upon a currency unit.
Various existing power generators or electric power generation facilities such as a diesel
generator, a file1 cell, and a cogeneration power generator may be used as the electric power
10 generation nleans provided in the electric power distribution stations. Furthennore, the system
may be configured to distribute excess electric po\vcr to the trunk line network. Alternatively,
the system may be configured to supply electric power to the demands fiom the external power
source and a plurality of electric power distribution stations in a mixed manner.
The respective portions of the aforementioned control station may be implemented by
15 using a co~nbinatiorot fhardware and software. In a forrn o ft he cornbination ofhardware and
software, a progranl according to the present invention is expanded into a RAM. The hardware
such as a CPU is operated in accordance with the program so as to allow respective poltions to
serve as a variety of means. This program may be recorded on a storage medium and
distributed. The program recorded on the storage medium is read into a rnelnorp via a wired
20 network, a wireless nehvork, or the storage medium itself so as to operate the CPU and the like.
Examples of tlie storage medium include an optical disk, a magnetic disk, a seiniconductor
memory device, a hard disk, and the like.
When the aforetnentioned embodiments arc translated into another expression, one or
more infol.mation processing apparatuses to be operated as a centralized control station can be
25 implemented by operating a CPU as a variety of means based upon a service pl.ogl.anr folmanaging
a distributed electric power generation system, which has been expanded into a RAM.
Fulthermore, the centralized control station may be i~npletnentedb y using a cloud system via the
Internet.
Although the present invention has been described with several embodiments, variations
30 such as separation or integration of the block configurations, rearrangement of the steps, and
col~lbinationo f part or all oft he contents of each ofthe embodiments into another cmbodime~lt
are possible as long as they meet the spirit of the prcsent invention and the aforemetltioned
ft~nctions. The following description docs not limit the prcscnt invention.
Some or all of the aforementioned embodiments may be described in the following
supplementary notes. Nevertheless, the present invention is not limited to following
supplementa~yn otes.
[Suppleme~~taNryo te]
A control station for distributed electric power generation characterized by comprising:
5 a power cut statns detection part operable to acqnire information on an electric power
distribution period used to calculate a period during which electric power supply is needed opon
an interruption of electric power supply from an external power sonrce in order to supply electric
power to a plurality of denland loads connected to a power transmission grid network with a
plurality of electric power distribution stations that can generate electric power npon the
10 interruption of the external power source;
an electric power demand monitor part operable to acquire an amount of power supply
demand to be supplied via the po\iter transmission grid net\vork during the period during \\~liicli
electric po\ver supply is needed, the period being determined from the information on the electric
power distribution period; and
15 an operating electric power generation facility determination part operable to select a
less costly combination of one or a required number of electric power distribution stations for
supplying electric power to the plurality of demand loads as electric power generation facilities
based upon a start and stop cost and a running cost of each of the electric power distribntion
stations in accordance \\it11 the calel~latede lectric po\trer distribution period and the a~nounot f
20 power supply demand.
[Supplementa~yN ote]
The control station as recited in the above supplementary note, cIial.aeterized by
selecting a tninimum number of electric po\ver distribution stations to be used for supplying
electric power that can cover tlie amoont of power supply de~nandf rom among a plurality of
25 possible selectable electric power distribution stations.
[Sopple~nentaryN ote]
The control station as recited in tlie above supplementary note, characterized by
selecting an increased number ofelectric power distribution stations that meet tlie a~nol~onft
power supply demand when no single electric power distribution station can generate an amount
30 of electric power that meets the aniount of power supply demand.
[Supplementary Note]
Tlie control statior~a s recited in the above supplenrentary note, characterized bj: tvhen
an amount of electric ponrer generation that meets the amount of power supply demand is to be
distributed, operating a plurality of electric power distribution stations in accordance \vith tl~c
amount of po\ver st~pplyd e~nands, witching a configuration of the power transmission grid
network, and determining a system configoration in which each of the electric power distribution
stations being operated supplies electric power to the detiiand loads assigned to the electric
power distribution station.
5 [Sopple~nentaryN ote]
The control station as recited in the above suppletnentaly note, characterized by, when
no electric power is received fiom the external power sonrce, connecting any of the electric
power distribution stations to be operated to a common po\ver line provided in the power
transmission grid network so as to determine a system configuration in which the demand loads
10 assigned to the clectric po\\'er distribution stations reccive electric power supply fiom another
electric power distribution station.
[Supplementary Note]
The control station as recited in the above supplementary note, characterized by, \\then
no electric power is receivcd fiom the external po\trer source, connecting any of the electric
15 power distribution stations to be operated to the demand loads assigned to an electric power
distribution station not to be operated that is located adjacent to the electric power distribution
station to be operated on a power line so as to determine a systelli configuration in which all of
tlie delnand loads receive electric power supply.
[Supplementary Notc]
20 The control statioll as rccited in the above supplementary note, characterized by, when
no electric po\zier is received from the external power source, connecting any of the electric
power distribution stations to be opcrated to the demand loads assigned to an electric po\irer
distribution station not to be opcrated that is located adjacent to the electric power distribution
station to he operated on a power line or connecting any of the electric power distribution
25 stations to be opcrated to tlie dcmand loads assigncd to an electric power distribution station not
to be operated with use ofa cor~~rnoplol rver line so as to detertnine a system configc~ratiotli n
\\~hicla~ll of tlie demand loads receive electric power supply.
[Supplementary Notc]
The control station as rccited in the above supplementary note, characterized by
30 calculating a predicted power cut period for power sltpplp interruption period infonilation
defining a period during which an inpot electric power is interrupted based upon infomatiotl on
power cuts that have been collected in the past and selecting a sy'sterrr corrfigtrration based trporr
the calculated predictcd po\ver cut period.
[Supplernentaty Note]
The control station as recited in the abovc supplenlentary note, characterized by, when a
power cut occurs in the external power source, using a threshold defining a predetemincd power
cl~pte riod during which the electric power distribotion stations that have supplied electric power
to tlie demand loads before the power cut are not operated to determine whether or not electric
5 power is supplied from an electric poiver distribution station other than the electric power
distribution stations that have supplied electric power to the demand loads.
[Supplementary Note]
The control station as recited in the above supplemetltary note, characterized by
selecting a systetn configuration with adding a po\ver transmission loss caused by electric power
10 distribution between tlie electric power distribution stations during a power cut of the external
power source to the costs.
[Supplementary Note]
The control station as recited in the above supplementary note, characterized by
distributing electric power distribotion stations to be operated based upon an operation history of
15 each of the electric power distribotion stations.
[Supplementary Note]
The control station as recited in the above supplctnentaly note, characterized in that:
some or all of the electric power distribution stations under the direction ofthe control
station have a battery facility as an electric power generation facilit): and
20 the battery facility is operated to reduce a running cost of another electric power
generation facility to select a less costly system configuration.
[Supplementary Note]
The control station as recited in the above sc~pplementa~nyo te, characterized in that:
sowe or all of the electric power distribution stations under tllc direction of the control
25 station have a batte~yf acility as an electric power generation facility, and
the battcty facility is operated to redace a rt~nningc ost of an electric power generation
facility having a lo\\' outpot but consuming a large amount of f11el to select a lcss costly system
configuration.
[Supplementary Note]
30 The control station as recited in the above supplementary note, characterized by
s\\titching power transmission distribution paths of the power transmission grid network by a
remote operation to connect the selected electric power distribution stations to the demand loads.
[Suppletncnta~yN ote]
The control station as recited in the above supplementa~yn ote, characterized by turning
on or off the electric power generation facilities oftlnc electric po\wler distribution stations to be
operated to connect the selected electric power distribution stations to the demand loads.
[Suppleinentat-)r Note]
The control station as recited in tlie above supplementary note, characterized by holding
5 startlstop-operation cost curve data indicative of changes in cost of each of tlne electric power
distribution stations with time and comparing the startlstop-operation cost curves of the electric
power distribution stations to select one or a required nutnber of electric po\wrer distribution
stations to be operated.
[Supplementary Note]
10 The control station as recited in the above suppleonentary note, characterized by
rcselecting the electric power distribution statiotis \\then the electric power distribution station
used to supply electric power is out of a predetermined eficie~ncyr ange due to a detnand
variatioti during the electric po\\?er distribution period of the electric power distribution stations.
[Suppletnenta~yN ote]
15 A control station operable to control individual amounts of power generation of a
plurality of power generators provided in a predetermined grid without any external power
source and to manage supply of electric power corresponding to a demand consutined in the
predetermined grid, characterized by:
acquiring information on an electric poww7er distribution period used to calculate a period
20 during \\~liicln electric power supply is needed upon an interruption of electric power supply from
the external po\wrer source and acquiring an amount of po~\lers upply demand that corresponds to
a demand co~nsumed in the predetermined grid during the period during which elcctric power
supply is needed, the period being determined from tlne acquired information on tlie electric
power distribution period, and
25 detertni~iing\v lietlter a single power generator capable of maintaining a predetermined
eficiencp for tlne demand can supply electric po\zrer based npon the calculated electric powwler
distribution period and the amount of power supply demand.
[Supple~nentaryN ote]
A distributed electric power generation system characterized by comprising:
30 a plurality of electric po\wrer distribution stations operable to receive electric power from
an external power source atnd generate electric power in a balanced inannet.;
a po\wrer transtnission grid network cotunected to the plurality of electric power
distribution stations for supplying received elcctric power to a plurality of detuand loads using
electric power; and
the control station as recited in the above supplementary note.
[Supplementary Note]
The distributed electric power generation system as recited in the above supplementary
note, characterized in that:
5 solne or all of the electric power distribution stations have a plurality of electric power
generation facilities, and
the control station selects a less costly co~nbinationo f electric power generation
facilities to be operated based upon a start and stop cost and a running cost of each of the electric
power generation facilities.
10 [Supplementary Note]
The distributed electric power generation system as recited in the above supple~nenta~y
note, characterized in that:
some or all ofthe electric power distribution stations have a plurality of electric power
generation facilities, and
15 the control station selects a less costly combination of electric po\ver generation
facilities to be operated based upon a start and stop cost and a runtling cost of each of the electric
powver generation facilities.
[Supplementa~yN ote]
'The distributed electric power generation system as recited in the above supplementary
20 note, characterized in that sonle or all ofthe electric po\trer distribution stations have a plurality
of types of electric power generation facilities.
[Supj)lementary Note]
The distributed electric power generation system as recited in the above supplen~entary
note, characterized in that sotne or all ofthe electric po\\rer distribution stations have a battery
25 facility as an electric power generation facility.
[Supplenienta~yN ote]
The distributed electric power generation system as recited in the above supplementary
note, characterized in that each of the electric power distribution stations receives electric power
via aclac conversion or acldc conversion fro111 the external po\ver source.
30 [Supplemental-)I Note]
A inethod of controlling distributed electric power generation with information
processing, characterized by comprising:
an inforn~ationa cquisition step of acquiring information on an electric power
distribution period used to calculate a period during which electric potver supply is needed upon
an interruption ofelectric power sopply fi.om an external ponrer source in order to supply electric
power to a plurality of demand loads connectcd to a power transmission grid nchvork with a
plurality of electric power distribution stations that can generate elcctric ponter upon the
interruption of the external power source and acquirirlg an amount of po\ver supply demand to be
5 supplied via the power transmission grid nehvork during the period during which electric pourer
supply is needed, the period being determined fiotn the acquired information on tlle electric
power distribution period; and
a selection step of selecting a less costly combination of one or a required number of
electric power distribution stations for supplying electric power to the plurality of dellland loads
10 as electric power generation facilities in advance or upon a power cut based upon a start and stop
cost and a running cost of each of the electric power distribution stations in accordance with the
calculated electric power distribution period and the amount of power supply demand.
[Sopplementa~yN ote]
The control tnethod as recited in the above supplementa~yn ote, characterized in that the
I5 selection step comprises selecting a minilnu~n number of electric power distribution stations to
be used for supplying electric power that can cover the amount of power supply demand fkom
atnong a plurality of possible selectable electric power distribntion stations.
[Supplementary Note]
The control tnethod as recited in the above supplementa~yn ote, characterized in that the
20 selection step cotnprises selecting an increased numbcr of electric po\tler distribution stations
that meet the amount of power supply demand whe11 no single electric power distribution station
can generate an amount of electric power tl~amt eets the arnonclt of po\ver supply demand.
[Supplementa~yN ote]
The neth hod of controlling distributed electric power generation as recited in the above
25 strpplen~eiltaryn ote, cllaracterized in that the selection step comprises, whe~al n a~nounot f
electric po\ver generation that meets the atnount of po\ver supply demand is to be distributed,
operating a plurality of electric power distribution stations in accordance with the amount of
power supply demand, switching a configuration ofthe power transmission grid network, and
determining a systenl configuration in \\rl~icle~a ch ofthe electric power distribution stations
30 being operated supplies electric po\xter to the demand loads assigned to the electric power
distribution station.
[Supplementa~yN ote]
The method of controlling distributed electric power generation as recited in the above
supplementa~yn ote, characterized in that:
the power transmission grid network includes a cotnmon power line to which each of
tlie electric power distribution stations and the demand loads assigncd to the electric po\wrer
distribution stations can be connected, and
the selection step comprises, when no electric power is received from the external
5 power source, connecting any of tlie elcctric power distribution stations to be operated to tlle
common power line so as to determine a system configuration in which the demand loads
assigned to the electric po\>ter distribution stations receive electric power supply from another
electric power distribution station.
[Supplementaty Note]
10 The method of controlling distributed electric power generation as recited in the above
suppletnentaty note, characterized in that tlie selection step comprises, when no electric po\vcr is
received f'rotn the external power source, connecting any of the electric power distribution
stations to be operated to the demand loads assigned to an electric power distribution station not
to be operated that is located adjacent to the electric power distribution station to be operated on
15 a power line so as to deterinine a system configuration in which all ofthe demand loads receive
electric power supply.
[Suppletnenta~yN ote]
Tlle method of controlling distributed electric power generation as recited in the above
supplementary note, characterized in that the selection step comprises, when no electric po\ver is
20 received from tlie external power source, connecting any of the electric power distribution
stations to be operated to the dcmand loads assigned to an electric power distribution station not
to be operated that is iocatcd adjacent to the electric power distribution station to be operated on
a po\ver line or connects any of the electric power distribution stations to be operated to tlie
demand loads assigned to all electric po\verdistrib~rtions tation not to be operaled \vith use of a
25 cotnnlon power line so as to determine a system configuration in which all of thc demand loads
receive electric po\ver supply.
[Supplementary Note]
The ~netl~oodf controlling distributed electric power generation as recited in the above
supplementa~yn ote, characterized in that
30 sonie or all ofthe electric po\lrcr distribution stations have a plurality of electric power
generation facilities, and
the selection step comprises selecting a less costly combination of electric power
generation facilities to be operated based upon a start and stop cost and a running cost of each of
the electric po\wler generation facilities.
[Supplementa~yN ote]
The method of contmlling distributed electric po\ver generation as recited in the above
sopplementaly note, characterized in that
some or all of the electric power distribution stations have a batte~yf acility as an
5 electric power generation facilit): and
the selection step comprises operating the battcry facility to reduce a running cost of
other electric po\ver generation facilities to select a less costly systenl configuration.
[Supplementary Note]
The method of controlling distributed electric po\vcr generation as recited in the above
10 supplenlenta~yn ote, characterized in that:
solne or all of the electric power distribution stations liave a batte~yfa cility as an
electric power generation facility, and
the selection step comprises operating the battery facility to reduce a running cost of an
electric po\ver generation facility having a low output but consuming a large amount of fuel to
15 select a less costly system configuration.
[Supplementa~yN ote]
The control mcthod as recited in the above supplenlentary note, characterized in that the
selection step comprises calculating a predicted power cut period for power supply interruption
period information defining a period during wl~icha n inpot electric power is interrupted based
20 upon information on power cuts that have been collected in the past and selecting a system
configuration based upon the calculated predicted power cut pcriod.
[Supplementa~yN ote]
The control method as recited in the above supplementary note, charactcrired in that the
selection step comprises, when a po\ver cut occurs in the external power source, using a
25 tl~resholdd efining a pretlctcr~ninedp ow\j,er cut period during wllich tlie electric ~)o\\~dcirs tribution
stations that liave supl~liede lectric power to the demand loads before tlle po\tler cut are not
operated to determine whether or not electric power is supplied from an electric power
distribution station other than the electric power distribution stations that have supplied electric
power to tlie demand loads.
30 [Supplementa~yN ote]
The control method as recited in the above supplementary note, characterized in that the
selection step comprises selecting electric power distribution stations to be operatcd with adding
a polver transmission loss causcd by electric power distribution between the electric power
distribution stations during a power cut of the external power source to the costs.
[Supplementary Note]
The contml method as recited in the above supplenlenta~y note, characterized in that the
selection step comprises distributing electric po\Irer distribution stations to be operated based
upon an operation history o f each of the electric power distribution stations.
5 [Supplementary Note]
The contml method as recited in the above supple~nentary note, characterized by
comprising a rernote operation step of switching power transmission distribution paths of the
power trans~nissio~grli d network by a remote operation to connect the selected electric power
distribution stations to the demand loads.
10 [Supplementa~Ny ote]
The method of controlling distributed electric po\rrer generation as recited in the above
supplementary note, characterized by comprising a remote operation step of turning on or o f f the
electric power generation facilities of the electric power distribution stations to bc operated to
connect the selected electric power distribution stations to the demand loads.
15 [Soppleinentary Note]
The control method as recited in the above supplementary note, characterizcd by
holding stal-tlstop-operation cost curve data indicative of changes in cost of each of the electric
power distribution stations with time and comparing the sta~z/stop-operation cost curves of the
electric power distribution stations to select one or a required number of electric power
20 distribution stations to be operated.
[Supplementary Note]
The contml tnethod as recited in the above supplementary note, characterized in that the
selection step comprises resclecting the electric po\trer distribution stations when the elcctric
power distribution station used to supply elcctric po\\'cr is out of a predetermined elliciency
25 range duc to a denland variation during the electric power distribution period o f the electric
power distribution stations.
[Sopplementary Note]
A contml method o f a control station operable to control individual amounts of power
generation of a plurality of power generators provided in a predetermined grid without any
30 external po\fler source and to supply electric power corresponding to a demand consumed in the
predetermined grid, characterized by:
acquiring information on all electric power distribution period used to calculate a period
doring \vl~icle~le ctric power supply is needed upon an interroption o fe lectric power slipply fro111
the external power source and acquiring an amount of po\ver supply demand that corresponds to
a demand consumed in the predetermined grid during the period during which electric power
supply is needed, the period being determined from the acquired information on the electric
power distribution period, and
determining whether a single power generator capable of maintaining a predeternlined
5 efficiency for the demand can supply electric power based upon the calculated electric power
distribution period and the amount of power supply demand.
This application claims the benefit of priority fiom Japanese patent application No.
2012-260151, filed on December 10, 2012, the disclosure ofwhich is incorporated herein in its
entirety by reference.
10
Descriptio~io f Reference Nmnerals and Signs:
1 distributed electric power generation systenl
100 ce~~tralizecdo ntrol station (control station, controlling apparatus)
110 electric power demand monitor part (electric power denland monitoring means)
15 120 operating electric power generation facility deternlination part (operating
electric power generation facility determination nieans)
121 selection part (selection means, determination means)
122 electric power generation facility information storage part (electric power
generation facility information storage means)
20 130 power cut status detection part (po\\ler cut status detection means)
140 co~i~municatiopna rt (comt~lonicatiomt~e ans)
200 electric power distribution station (electric power generation facility, battery
facility)
300 power transmission grid network

CLAIMS
1. A distributed electric power generation system characterized by comprising:
a plurality of electric power distribution stations operable to receive electric po~ver from
5 an external power source and generate electric power in a balanced manner;
a power transmission grid net~vorkc onnected to the plurality of electric po\\'er
distribution stations for supplying received electric power to a plurality of demand loads using
electric po\tlet.; and
a control station operable to:
10 acquire information on an electric power distribution period used to calculate a
period during which electric powcr supply is needed,
acquire an aii~ounto fp ower supply demand to be supplied via the power
transmission grid nehvork during the period during which electric power supply is needed, the
period being determined fro111 the acquired infor~nationo n the electric power distribution period,
15 and
select a less costly combination of one or a required number of electric power
generation facilities for supplying electric power to the plurality of demand loads based upon a
start and stop cost and a running cost of each of the electric powcr distribution stations in
accordance with the calculated electric power distribution pcriod and the amount of power
20 supply demand.
2. The distributed electric power generation system as recited in claim 1 , characterized in
that tlie control station selects a minimum number of electric po\\'er distribution stations to be
used for supplying electric power that can cover tlie anioont of power supply demand froin
25 among a plurality of possible selectable electric power distribution stations.
3. Tllc distributed electric power generation system as recited in clai~n 1 or 2,
characterized in that the control station selects an increased nomber of electric power distribution
stations that meet the amount of power supply demand when no single electric power
30 distribution station can generate an amount of electric power that meets the amount of po\ver
supply demand.
4. 'llie distributed electric power generation system as recited in any one of claims 1 to 3,
cllaracterized in that, when an amount of electric powc~~gcneratiothna t meets the amount o f
power supply demand is to be distributed, the control station operates a plurality of electric
power distribution stations in accordance with the amount of powver supply demand, switches a
configuration of the powver transmission grid network, and determines a system configuration in
whicll eacli of the electric power distribution stations being operated supplies electric power to
5 the denland loads assigned to the electric power distribution station.
5. The distributed electric power gcneration system as recited in any one of clai~iisI to 4,
characterized in that:
the power transmission grid network includes a common powver line to which each of
10 the electric po\ver distribution stations and the demand loads assigned to the electric power
distribution stations can be connected, and
\vIieti no electric power is received from the external power source, the control station
connects any oftlie electric power distribution stations to be operated to the comnion power line
so as to determine a system configuration in \vhich the denland loads assigned to the electric
15 po\ver distribution stations receive clectric power supply from another electric power distribution
station.
6. The distributed electric power generation system as recited in any one of claims I to 5,
characterized in that, when no electric power is received from the external power source, the
20 control station connects any of the electric power distribution stations to be operated to the
demand loads assigncd to an electric ponrer distribution station not to be operated that is located
adjacent to the electric power distribution station to be operated on a power line so as to
determine a system configuration in which all of the demand loads receive electric power supply.
25 7. The distributed electric power gcncration systctn as recited in any one of claims I to 6,
characterized in that, whet1 no electric potver is received fiorn the external ponter source, the
control station connects any of the electric power distribution stations to be operated to the
demand loads assigned to an elcctric power distribution station not to be operated that is located
adjacent to the electric power distribution station to be operated on a power line or connects any
30 of the electric power distribution stations to be operated to the demand loads assigned to an
electric power distribution station not to be operated with usc of a common power line so as to
deternlitie a system configuration in whicli all of llle dctnarrd loads receive electric potver.stip(~lp.
8. The distributed electric power generation system as recited in any of claims I to 7,
characterized it1 that:
sotne or all ofthe electric powwier distribution stations have a plurality of electric pourer
gencration facilities, and
the cotltml station selects a less costly combination of electric power generation
5 facilities to be operated based upon a start and stop cost and a running cost of each of the electric
power generation facilities.
9. The distributed electric power get~erations ystem as recited in any of claims 1 to 8,
characterized in that-some or all of the electric power distribution stations have a plurality of
10 types of electric power generation facilities.
10. The distributed electric power generation systetn as recited in any of claims 1 to 9,
characterized in that some or all of the electric power distribution stations have a battery facility
as an electric powver generation facility.
15
11. The distributed electric power generation systetn as recited in any of claims 1 to 10,
characterized in that each ofthe electric power distribution stations receives electric po\wrer via
aclac conversion or acldc conversion from the cxtertlal power source.
20 12. The distributed electric power generation systenl as recited in any ofclai~lls1 to I I ,
characterized in that the control station sw\iitches power transmission distribution paths of the
power transmission grid nehork by a remote operation to connect the selected electric po\wre1
distribution stations to the demand loads.
25 13. Tl~ed istributed electric po\\'cr generation system as recited in any of cIai111s1 to 12,
characterized in that tl~eco ntrol station holds sta~tlstop-operationc ost curve data indicative of
changes in cost of each of the electric power distribution stations with time and compares the
startlstop-operation cost curves of the electric power distribution stations to select one or a
required number of electric powver distribution stations to be operated.
30
14. Tlle distributed electric po\ver generation systetl~a s recited in any of claims I to 13,
characterized in that the control station reselects the electric power distribution stations when the
electric power distribution station used to supply electric power is out of a predetermined
efficiency range due to a demand variatiotl during the electric power distribution period of the
electric power distribution stations.
15. A distributed electric po\ver generation systenl operable to cont~oiln dividual amourtts
of power generation of a plurality of pon7er generators provided in a predetermined grid without
5 any external power source and to supply electric power corresponding to a demand consumed in
the predetermined grid, characterized by comprising:
a control station operable to:
acquire infonnation on an electric power distribution period used to calculate a
period during which electric power supply is needed up011 an interruption of electric po\ver
10 supply fiom the external power soorcc and acquire an amount of power supply denland that
corresponds to a denland consumed in the predetermined grid during the period during which
electric power supply is needed, the period being determined from the acquired infortnation on
the electric power distribution period, and
determine whether a single power generator capable of maintaining a
15 predetermined efliciency for the demand can supply electric power based upon the calculated
electric power distribution period and the aniount of power supply demand.
16. A control station for distributed electric power generation characterized by comprising:
a power cut status detection part operable to acquire information on an electric po\\'er
20 distribution period used to calculate a period during which electric power supply is needed upon
an interruption of electric power supply from an external po\ver source in order to supply electric
power to a plurality of demand loads connected to a power transmission grid network ntith a
plurality of electric po\ver distribution stations that can generate electric power upon the
interruption of thc external power source;
25 an electric po\ver dcn~andn ~onitorp art operable to acquire a11a mount of po\ver supply
demand to bc supplied via the po\vcr transn~ission grid net\vork during the period during wliich
electric power supply is needed, the period being determined fro111 the information on the electric
power distribution period; and
an operating electric po\\ier generation facility detem~inationp art operable to select a
30 less costly combination of one or a required number of electric power distribution stations for
supplying electric power to tl~ep lurality of demand loads as electric power generation facilities
based upon a start and stop cost and a running cost of each of the electric po\trer distribution
stations in accordance with tllc calculated electric power distribution period and the amount of
power supply demand.
17. The control statioti as recited in claim 16, characterized by selecting a minimo~n number
of electric power distribution stations to be used for supplying electric power that can cover the
amount of power supply detnand from among a plurality of possible selectable electric power
5 distribution stations.
18. The control station as recited in claim 16 or 17, characterized by selecting an increased
number of electric power distribution stations that meet the amount of powver supply demand
when no single electric power distribotion station can generate an alllount of electric power that
10 tneets the anlount of power supply demand.
19. The control station as recited in any one of clai~lls1 6 to 18, characterized b~:w hen an
amount ofelectric pourer generation that meets the a~noonot f power supply demand is to be
distributed, operating a plurality of electric power distribution stations in accordance with the
15 amount of po\wrer supply demand, switching a configuration of the power transmission grid
nehvork, and deterniining a systetm configuration in which each of the electric power distribution
stations being operated supplies electric powver to the demand loads assigned to the electric
power distribution station.
20 20. The control station as recited in any one of clainls 16 to 19, characterizcd b): when no
electric power is received from the external power source, connecting any of the electric power
distribution stations to be opcrated to a cotntnon power line provided in the power transmission
grid network so as to determine a system corifig~~ratioinn \\chic11 the demand loads assigned to
the electric power distribution stations receive electric powver supply fro111 another electric powver
25 distribution station.
21. 'I'he control statio11 as recited in any one of claims I6 to 20, characterized b): \vIlen no
electric power is received from the external power source, connecting any ofthe electric po\wler
distribution stations to be operated to the demand loads assigned to an electric power distribution
30 station not to be operated that is located adjacent to the electric power distribution station to be
operated on a power line so as to determine a systetll configuration in which all of the demand
loads receive electric power supply.
22. The coiitrol station as recited in any one of claims 16 to 21, characterized b~: whcn no
electric po\ver is received fiom the external po\jler source, connecting any ofthc electric power
distribution stations to be operated to the deinand loads assigned to an electric power distribution
station not to be operated that is located adjacent to the electric power distribution station to be
operated on a power line or contiecting any o f the electric po\\(er distribution stations to be
5 operated to the demand loads assigned to an electric power distribution station not to be operated
with use of a common po\tler line so as to determine a system configuration in which all of the
demand loads receive electric power supply.
23. The control station as recited in any one ofclaims 16 to 22, characterized by calculating
10 a predicted power cut period for power supply interruption period information defining a period
during wllicli an input electric power is interrupted based upon information on power cuts that
have been collected in the past and selecting a system configuration based upon the calculated
predicted power cut period.
15 24. The control station as recited in any one ofclaims 16 to 23, characterized b): wllen a
power cut occurs in the external power source, using a threshold defining a predetermined power
cut period during which the electric power distribution stations that have supplied electric power
to the demand loads before the power cut are not operated to determine whether or not electric
power is supplied from an electric power distribution station othcr than the electric power
20 distribution stations that have supplied electric power to the demand loads.
25. Tlie control station as recited in any one of claims 16 to 24, characterized by selecting a
system configl~ratiow~i~th adding a power trans~nissionl oss caused by electric power
distribution between the electric power distribution stations dt~ringa power cut oft he external
25 po\ver source to the costs.
26. A incthod of controlling a distributed clcctric power generation systctii, cliaracterizcd by
comprising:
an inforn~ationac quisition step of acquiring information on an electric power
30 distribution period used to calculate a period during which electric power supply is needed upon
an interruption of electric power supply fiom an external po~vcr source in order to supply electric
power to a plurality of demand loads connected to a power transmission grid nchvork with a
plurality of electric power distribution stations that can gencratc clcctric power upon the
intenupti011 of the external power source and acquiring an amount of po\vcr supply demand to be
supplied via the power transmission grid network during the period during which electric power
supply is needed, the period being determined from the acquired information on the electric
power distribution period; and
a selection step of selecting a less costly combination of one or a required number of
5 electric power distributiot~s tations for supplying electric power to the plurality of demand loads
as electric power generation facilities based upon a start and stop cost and a running cost of each
of the electric power distribution .s .t ations in accordance with the calculated electric power
distribution period and the amount of power supply demand.
10 27. The method of controlling a distributed electric power generation system as recited in
claim 26, characterized in that the selection step comprises selecting a less costly combination
with use of a currency unit as a unit indicative of values ofthe start and stop cost and the running
cost.