DESCRIPTION
DEVICE, SYSTEM, AND METHOD FOR MANAGING POWER
TECHNICAL FIELD
[OOO 11
The present invention relates to techniques for managing the electric power in a
plurality of facilities.
5 BACKGROUND ART
[0002]
In recent years, the research and development of a smart grid and/or a microgrid
introducing information and communication technologies are actively conducted. Here,
actually-proved type technology development intended to achieve a reduction in carbon
10 emissions and an economical power operation is mainly conducted. Furthermore, on the
consumer sides, such as factories, buildings, and houses, more efficient energy management
methods utilizing distributed power sources, such as natural energy, such as photovoltaic power
generation, and rechargeable batteries are under study. In such energy management methods,
for example based on the situations of consumers, distributed power sources are controlled via
15 communication to equalize loads and/or interchange electric power.
[0003]
For example, there is known a technology, in which when a plurality of
microgrids are connected to each other via a network and electric power is supplied in
accordance with a request from a consumer, the power status is compared between its own
20 microgrid and another microgrid and power transaction with the another microgrids is controlled
depending on the comparison result. Moreover, for example, there is known a technology (e.g.,
Patent Literatures 1,2), in which the voltage at a system link point of each of consumers having
a distributed power source is measured, a consumer, in which the voltage at the system link point
departs from a specified voltage value or is likely to depart therefrom, is found, the priority of
25 the consumer is determined with reference to the customer information, and output adjustment is
performed on a consumer of a lower priority.
CITATION LIST
PATENT LITERATURE
[0004]
PATENT LITERATURE 1 : JP-A-20 1 1-229268
PATENT LITERATURE 2: JP-A-2006- 14906 1
SUMMARY OF INVENTION
5 TECHNICAL PROBLEM
[0005]
With a technique, in which a consumer requests for electric power using user
authentication, it is impossible to autonomousiy interchange eiectric power in accordance with
an increase or decrease in demand, such as load fluctuation. Moreover, in a technique in which
10 a system management device controls the distributed power sources of consumers, the
information regarding the consumers need to be centrally managed.
SOLUTION TO PROBLEM
[0006]
In order to solve the above-described problems, a power management device
15 according to one aspect of the present invention includes a communication unit and a
determination unit. The communicatioll unit transmits to a communication network first
prediction data indicative of a prediction value of a demand-and-supply balance of electric power
of a first facility having a power supply and linking to a power system. Upon receipt of a
message to request for power interchange from another power management device which
20 transmits to the communication network second prediction data indicative of a prediction value
of a demand-and-supply balance of electric power of a second facility linking to the power
system, the communication unit receives the second prediction data from the communication
network. The determination unit determines based on the first prediction data and the second
prediction data whether or not the power interchange is possible. When it is determined that the
25 power interchange is possible, the communication unit transmits to the another power
management device a message to permit the request.
ADVANTAGEOUS EFFECTS OF INVENTION
[0007]
The power supplies provided in a plurality of facilities can be efficiently utilized.
30 BRIEF DESCRIPTION OF DRAWINGS
4
[0008]
[FIG. 11 FIG. 1 illustrates the configuration of a distributed energy management
system.
[FIG. 21 FIG. 2 illustrates the management data of xEMS(1) in a common data
5 area.
[FIG. 31 FIG. 3 illustrates the management data of xEMS(2) in the common data
area.
[FIG. 41 FIG. 4 illustrates management data output processing.
[FIG. 51 FIG. 5 iIIustrates the configuration of factories managed by the
10 distributed energy management systems.
[FIG. 61 FIG. 6 illustrates a relationship between a prediction power and a target
power.
[FIG. 71 FIG. 7 illustrates cooperation request processing.
[FIG. 81 FIG. 8 illustrates a specific example of the operation of distributed
15 energy management systems.
DESCRIPTION OF EMBODIMENTS
[0009]
Hereinafter, a distributed energy management system is described which is an
application example of a power control system according to one aspect of the present invention.
20 [OOlO]
FIG. 1 illustrates the configuration of the distributed energy management system.
This distributed energy management system includes a data field 10, a plurality of energy
management systems 1 1, a gateway 17, and an energy management system 16. Each of the
plurality of energy management systems 11 and the energy management system 16 is a
25 subsystem of an autonomous distributed network. The plurality of energy management systems
11 are directly connected to the data field 10. The energy management system 16 is connected
to the data field 10 via the gateway 17.
[OOll]
In the drawings and the following description, each of the plurality of energy
30 management systems 11 may be referred to as xEMS (x energy management system). For
example, when a target facility which is the facility to be managed by xEMS is a factory, a
building, or a home, xEMS is referred to as a factory energy management system, a building
energy management system, or a home energy management system depending on the target
facility, respectively. Moreover, the target facility includes a load which consumes electric
power and a power supply which supplies electric power. Since this power supply is distributed
across subsystems, it is also referred to as a distributed power source.
[00 1 21
5 The data field 10 is a communication network for the autonomous distributed
network and circulates the management data output from each xEMS. Each xEMS may
transmit the management data to the data field 10 by broadcasting. In this case, each xEMS
may receive necessary management data. Moreover, a server inside the data field 10 may store
the management data transmitted from each xEMS. In this case, the server inside the data fieid
10 10 may transmit the management data, which is requested by each xEMS, to a request sender.
[00 131
A subsystem number is assigned to the plurality of energy management systems
11, respectively, so that each of the plurality of energy management systems 11 is referred to as
xEMS(l), ..., xEMS(5). Furthermore, a subsystem number is assigned also to the energy
15 management system 16, so that the energy management system 16 is referred to as xEMS(6).
Note that there is no limit on the number of subsystems.
[00 1 41
The energy management system 1 1 includes a communication unit 3 1, a
determination unit 32, and a management unit 34. The communication unit 3 1 transmits its
20 own management data to the data field 10, and receives the management data of another xEMS
from the data field 10. The determination unit 32 performs the determination for power
management, based on the management data. For each xEMS, a target period which is the
period of management is set in advance. The target period is one day on the operating day of a
factory, for example. Moreover, the determination unit 32 predicts the power consumption and
25 supply power of a target facility in a target period. The power consumption of a target facility
is the consumption by a load, the charging of a rechargeable battery, and the like inside the target
facility. The supply power of a target facility comes from the power generation by a power
generator, the discharging of a rechargeable battery, and the like inside the target facility. The
management unit 34 manages the electric power of a target facility. For example, the
30 management unit 34 controls the power consumption and supply power inside a facility by
controlling a power convei-ter, a load, a breaker, and the like inside a facility.
[00 151
The energy management system 16 includes the same management unit 34 as the
energy management system 1 1. The gateway 17 includes the same comn~unicationu nit 3 1 and
determination unit 32 as the energy management system 11. Even a subsystem having neither
the communication unit 3 1 nor the determination unit 32 unlike the energy management system
16 can connect to the data field 10 via the gateway 17.
[00 1 61
5 Each xEMS is a computer with a microprocessor and a memory. In this case, a
program stored in the memory causes the microprocessor to function as xEMS.
[00 171
FIG. 2 illustrates the management data of xEMS(1) in a common data area. This
state is the state where xEMS(i) has not yet established a cooperative relationship with another
10 xEMS.
[00 1 81
The data field 10 provides a common data area D 1. The common data area D 1
includes management data areas D 1 1, D 12, D 13, D 14, D 15, and D 16 each corresponding to each
of xEMS(1) to xEMS(6). The management data area stores the management data of the
15 corresponding xEMS, so that the data field 10 integrally manages the management data. When
each xEMS transmits the management data to its own management data area and needs the
management data of another xEMS, each xEMS selects the corresponding management data area
and receives the management data inside the selected management data area.
[0019]
2 0 Here, the management data 11 0 of xEMS(1) stored in the management data area
D 1 1 is described. The management data 1 10 includes prediction power information 1 1 1, target
power information 1 12, and determination illformation 1 13. All the management data have the
same data format.
[0020]
2 5 The prediction power information 1 I1 indicates the prediction power of xEMS(1).
The target power information 112 indicates the target power of xEMS(1).
1002 11
The target power is set in advance for each xEMS. The target power indicates
the upper limit of the purchased power from a commercial power system. The determination
30 unit 32 calculates a prediction power which is a prediction value of the purchased power in a
target period, based on the power consumption and supply power of a target facility in the target
period. The purchased power is an electric power obtained by subtracting the supply power of
a target facility fiom the power consumption of the target facility. The purchased power is
required to fall below the target power. The prediction power and target power may be
expressed in electric power or may be expressed in electric energy. Moreover, the prediction
power indicates a prediction value for every predetermined time interval in the target period.
The time interval is one hour, for example.
[0022]
5 The determination information 11 3 indicates the determination result of whether
or not all the prediction powers in a target period are equal to or less than a target power. When
all the prediction powers in the target period are equal to or less than the target power, the
determination information 113 indicates "OK." When any one prediction power in the target
period exceeds the target power, the determination information i 13 indicates "NG."
10 [0023]
The management data 11 0 of xEMS(1) circulates in the data field 10 in this
manner, so that xEMS(2) to xEMS(6) can obtain the management data 110 of xEMS(1).
[0024]
FIG. 3 illustrates the management data of xEMS(2) in the common data area.
15 This state is the state where xEMS(2) has a cooperative relationship with xEMS(1). In this
cooperative relationship, xEMS(2) supplies electric power to xEMS(1) in response to a request
from xEMS(1). That is, electric power is supplied to a load of a target facility of xEMS(1) from
the power supply of a target facility of xEMS(2). The management data 120 of xEMS(2) has
the same format as the management data 1 10, and includes prediction power information 121,
20 target power information 122, and determination information 123. The prediction power
information 12 1 indicates the prediction power of xEMS(1) in addition to the prediction power
of xEMS(2). The target power information 122 indicates the target power of xEMS(1) in
addition to the target power of xEMS(2).
[0025]
2 5 In establishing a cooperative relationship in response to a request from xEMS(l),
the determination unit 32 of xEMS(2) obtains the management data 110 of xEMS(1) from the
management data area D 1 1 of the data field 10, and generates the management data 120 of
xEMS(2) based on the management data 11 0. Next, the communication unit 3 1 of xEMS(2)
transmits the generated management data 120 to the management data area D 12 of the data field
30 10.
[0026]
IHereinafter, management data output processing is described, which is the
processing for each xEMS to output the management data to the data field 10. Here, suppose
the target facility is a factory. Moreover, here, the mailagernent data output processing by
xEMS(1) is illustrated. Other xEMS performs the same operation.
[0027]
FIG. 4 illustrates the management data output processing. Each xEMS performs
the management data output processing at a specified time every day. For example, each xEMS
5 performs the management data output processing at 8:00 a.m. prior to the operation of a factory
every day.
[0028]
First, in S 1, xEMS(1) obtains preliminary information and generates the target
power information 11 2 based on the obtained preiiminary information. The preliminary
10 information includes a target power, weather information, production planning information, and
performance information. The production planning information indicates the production plan
of a target factory, for example. The performance information indicates the performances, such
as power consumption and supply power, in a target factory. The preliminary information may
be stored in a storage unit inside xEMS or may be received via a communication network from a
15 server outside xEMS.
[0029]
Next, in S2, based on the preliminary information, xEMS(1) predicts the power
consumption and supply power inside a target factory, and establishes an operation plan of the
target factory in a target period. The operation plan indicates the operation of the load and
20 power supply inside the target factory.
[0030]
Next, in S3, xEMS(1) calculates a prediction power based on the operation plan,
and generates the prediction power information 11 1 based on the calculated prediction power.
[003 11
2 5 Next, in S4, xEMS(1) determines whether or not the prediction power is equal to
or less than a target power.
[0032]
When it is determined that the prediction power is equal to or less than the target
power (S4, YES), then in S5 xEMS(1) writes "OK" into the determination information 11 3,
30 thereby causing the processing to transition to S7. Note that xEMS(1) may write "OK" into the
determination information 11 3 when a value obtained by adding a predetermined margin to the
prediction power is equal to or less than the target power.
[0033]
When it is determined that the prediction power is neither equal to nor less than
the target power (S4, NO), then in S6 xEMS(1) writes "NG" into the determination information
113, thereby causing the processing to transition to S7.
[0034]
In S7, xEMS generates the management data 11 0 including the prediction power
5 information 1 1 1, the target power information 1 12, and the determination information 1 13, and
outputs the generated management data to its own management data area D 11 in the data field
10.
[0035]
The above is the management data output processing.
10 [0036]
Hereinafter, a specific example of the configuration of the distributed energy
management system when the target facilities are factories is described.
[0037]
FIG. 5 illustrates the configuration of factories managed by the distributed energy
15 management system. In this example, a demand facility is a factory 21 and xEMS is a factory
energy management system (FEMS) 1 1. A commercial power system 60 supplies electric
power to a factory power system 62 via a transformer 61. The factory power system 62
supplies electric power to a plurality of factories 2 1. That is, the plurality of factories 2 1 are
linked to the factory power system 62. The factory power system 62 may supply electric power
20 to a low-voltage system 64 via a transformer 63.
COO3 81
The factory 21 includes FEMS 11, a load 41, a PCS (power conditioning system)
42, a distributed power source, a wattmeter 5 1, a breaker 52, and a transformer 53. The
distributed power source is for example a PV (photovoltaic power generation) 42, a rechargeable
25 battery 43, or the like. In the drawings and the following description, one of two factories 21 is
referred to as a factory(1) and the other is referred to as a factory(2). Moreover, FEMS 11
which manages the factory(1) is referred to as FEMS(1) and FEMS 11 which manages the
factory(2) is referred to as FEMS(2).
[0039]
30 The wattmeter 5 1 m,easures an electric energy purchased from the commercial
power system 60 to the factory 21 and a sold electric energy from the factory 21 to the
commercial power system 60, and transmits the measured results to FEMS 11. The breaker 52
disconnects a part of the wirings in the premise in response to an instruction from FEMS 11.
The load 41 consumes the electric power coming from the factory power system 62 and PCS 42.
The transformer 53 converts a voltage between the factory power system 62 and PCS 42. PCS
42 converts a DC power output from the distributed power source to an AC power. Moreover,
PCS 42 may switch the chargingldischarging of the rechargeable battery 43. FEMS 11 controls
PCS 42 based on the operatioil plan.
5 [0040]
FEMS 11 is connected to the data field 10. FEMS(1) writes the management
data 11 0 into the management data area D 11 inside the common data area Dl. FEMS(2) writes
the management data 120 into the management data area D 12 inside the common data area Dl.
Ivioreover, FEMS(1) can read the management data 120 from the management data area Dl2 of
10 FEMS(2). Similarly, FEMS(2) can read the management data 110 from the management data
area Dl 1 of FEMS(1).
LO04 11
Hereinafter, a specific example of the prediction power and target power in
FEMS(1) and FEMS(2) is described.
15 [0042]
FIG. 6 illustrates a relationship between a prediction power and a target power.
This graph illustrates a comparison result 2 13 between a prediction power 2 11 and a target power
212 in FEMS(l), and a comparison result 223 between a prediction power 221 and a target
power 222 in FEMS 120. Furthermore, this graph illustrates a colnparison result 233 between a
20 total prediction power 23 1 which is a sum of the prediction power of FEMS(1) and the
prediction power of FEMS(2) and a total target power 232 which is a sum of the target power of
FEMS(1) and the target power of FEMS(2). That is, when FEMS(1) and FEMS(2) have a
cooperative relationship with each other, the total prediction power 23 1 is a sum of the prediction
power 21 1 and the prediction power 221, and the sum target power 232 is a sum of the target
25 power 212 and the target power 222. Moreover, the prediction power 21 1, the prediction power
22 1, and the total prediction power 23 1 each indicate a temporal change for every time interval
within a target period.
COO431
According to the comparison result 213 of FEMS(l), there is a period of time
30 during which the prediction power 21 1 exceeds the target power 212. According to the
comparison result 223 of FEMS(2), there is a room for the prediction power 221 to reach the
target power 222.
LO0441
Moreover, according to the total comparison result 233, the total prediction power
11
23 1 does not exceed the total target power 232. Accordingly, FEMS(1) and FEMS(2) establish
a cooperative relationship with each other and the FEMS(2) supplies a part of the supply power
within the factory(2) to the factory(l), so that a shortage of the supply power within the
factory(1) can be dissolved.
5 [0045]
Hereinafter, cooperation request processing is described, in which a certain xEMS
requests another xEMS for cooperation (power interchange) when the certain xEMS predicts a
shortage of the target power.
/0046]
10 FIG. 7 illustrates the cooperation request processing. Here, suppose that a
distributed energy management system has N xEMS1s. Moreover, each xEMS is designated by
xEMS(i) by using a subsystem number i which is an integer from 1 to N. xEMS(i) executes the
cooperation request processing when the determination information of xEMS(i) is "NG" as a
result of the management data output processing.
15 [0047]
First, in S 11, xEMS(i) substitutes the value of i into a variable j.
[0048]
Next, in S12, xEMS(i) determines whether or not j=N.
[0049]
20 When not j=N (S12, NO), i.e., when there is any xEMS having the subsystem
number larger than i, then in S 13 xEMS(i) calculates a value by adding one to i and substitutes
the calculated value into a new i, and causes the processing to transition to S 15.
[OOSO]
When j=N (S 12, YES), i.e., when there is no xEMS having the subsystem number
25 larger than i, then in S14 xEMS(i) substitutes one into i, and causes the processing to transition
to S15.
[005 11
In S 15, xEMS(i) determines whether or not xEMS(j) has already established a
cooperative relationship with another xEMS. Here, xEMS(i) obtains the management data of
30 xEMS(j) from the data field 10, and when the data of the another xEMS is included in the
management data of xEMS(j), xEMS(j) determines that it has already established a cooperative
relationship with the another xEMS.
[0052]
When it is determined that xEMS(j) has already established a cooperative
relationship with the another xEMS (S 15, YES), xEMS(i) causes the processing to transition to
S12.
[0053]
When it is determined that xEMS('j) has not yet established a cooperative
5 relationship with the another xEMS (S 15, NO), in S 16, xEMS(i) determines whether or not the
determination information of xEMS(j) is "OK".
[0054]
When the determination information of xEMS(j) is "NG" (S16: NO), i.e., when
the target power of xEIviS(j) does not have a margin, xEIviS(i) causes the processing to transition
10 toS12.
[0055]
When the determination information of xEMS(j) is "OK" (S16: YES), i.e., when
the target power of xEMS(i) has a margin, then in S 17 xEMS(i) transmits to xEMS(j) a message
to request for cooperation, and completes this flow.
15 [0056]
The above is the cooperation request processing.
LO0571
Once xEMS('j) transmits to xEMS(i) a message to permit cooperation after
xEMS(i) transmits to xEMS('j) the message to request for cooperation, the cooperative
20 relationship between xEMS(i) and xEMS(j) is established. On the other hand, when xEMS(j)
transmits to xEMS(i) a message to refuse cooperation, the cooperative relationship between
xEMS(i) and xEMSQ) will not be established.
[0058]
With this cooperation request processing, when the target power of xEMS is
25 insufficient, xEMS can request another xEMS for power interchange.
[0059]
Hereinafter, a specific example of the operation of a distributed energy
management system including the cooperation request processing is described.
[0060]
3 0 FIG. 8 illustrates a specific example of the operation of the distributed energy
management system. This sequence diagram illustrates the operations of xEMS(l), xEMS(2),
xEMS(3), and the data field 10.
[006 I]
First, in S 10 1, xEMS(1) determines wl~ethero r not the target power is sufficient.
Similarly in S102, xEMS(2) determines whether or not the target power is sufficient. Similarly
in S103, xEMS(3) determines whether or not the target power is sufficient. Here, a case is
illustrated where the target power of xEMS(1) is insufficient, the target power of xEMS(3) is
sufficient, and the target power of xEMS(2) is sufficient. That is, here, a case is illustrated
5 where the determination information of xEMS(1) is "NG", the determination information of
xEMS(2) is "OK", and the determination inforniatio~ol f xEMS(3) is "OK".
[0062]
Next, in S 11 1, xEMS(1) transmits a message to request for cooperation to
xEMS(2) with the subsystem number next to the subsystem number of xEMS(1) through the
10 cooperation request processing.
[0063]
Next, in S 112, xEMS(2) requests the data field 10 for the management data of the
request sender xEMS(1). Next, in S113, xEMS(2) receives the management data of xEMS(l),
adds the management data of xEMS(1) to its own management data to generate its own
15 management data, and transmits the same to the data field 10.
[0064]
Next, in S 114, xEMS(2) determines whether or not a total prediction power of
xEMS(1) and xEMS(2) is within an appropriate range, based on the management data of
xEMS(1) and xEMS(2). Here, for example, xEMS(2) determines, when a total prediction
20 power of xEMS(1) and xEMS(2) is equal to or less than a total target power of xEMS(1) and
xEMS(2), that the total prediction power is within an appropriate range. Note that, xEMS(2)
may determine, when a value obtained by adding a predetermined margin to a total prediction
power is less equal to or less than a total target power, that the total prediction power is within an
appropriate range.
25 [0065]
When it is determined that the total prediction power is within an appropriate
range (S 114: YES), then in S115 xEMS(2) transmits a message to permit cooperation to
xEMS(1). Next, in S116, xEMS(1) has established a cooperative relationship with xEMS(2) and
completes this sequence.
30 [0066]
When it is determined that the total prediction power is not within an appropriate
range (S 1 14: NO), then in S 1 17 xEMS(2) clears the management data of xEMS(1) within its own
management data. Next, in S118, xEMS(2) transmits a message to refuse cooperation.
[0067]
Next, in S121, upon receipt of the message to refuse cooperation, xEMS(1)
transmits to xEMS(3) with a subsystem number next to the subsystem number of xEMS(2) a
message to request for cooperation through the cooperation request processing, and performs the
same processing as those of S 11 1 to S 11 8.
5 [0068]
Next, in S 122, xEMS(2) requests the data field 10 for the management data of the
request sender xEMS(1). Next, in S123, xEMS(2) receives the management data of xEMS(l),
adds the management data of xEMS(1) to its own management data to generate its own
management data, and transmits the same to the data field 10.
10 [0069]
Next, in S 124, xEMS(2) determines whether or not a total prediction power of
xEMS(1) and xEMS(2) is within an appropriate range, based on the management data of
xEMS(1) and xEMS(2). Here, for example, xEMS(2) determines, when a total prediction
power of xEMS(1) and xEMS(2) is equal to or less than a total target power of xEMS(1) and
15 xEMS(2), that the total prediction power is within an appropriate range.
[0070]
When it is determined that the total prediction power is within an appropriate
range (S 124: YES), then in S 125 xEMS(2) transmits a message to permit cooperation to
xEMS(1). Next, in S126, xEMS(1) establishes a cooperative relationship with xEMS(2) and
20 completes this sequence.
[0071]
When it is determined that the total prediction power is not within an appropriate
range (S 124: NO), then in S 127 xEMS(2) clears the management data of xEMS(1) within its
own management data. Next, in S128, xEMS(2) transmits a message to refuse cooperation.
25 [0072]
If there is any xEMS with the subsystem number next to the subsystem number of
xEMS(2), the same processing as those of S111 to S 11 8 will be performed.
[0073]
The above is a specific example of the operation of the distributed energy
30 management system.
[0074]
With this operation, a request destination xEMS can manage the electric power of
a request sender and request destination using a total of the prediction power of the request
sender and its own prediction power and a total of the target power of the request sender and its
own target power.
[0075]
Note that, xEMS may modify the prediction power every one hour. When the
prediction power exceeds a target power as a result of the modification, xEMS performs the
5 cooperation request processing and repetitively performs this processing until the operation plan
for one day is completed.
[0076]
When the determination information of a request destination subsystem is "NG",
when the request destination subsystem has already established a cooperative relationship with
10 another subsystems, or when it is determined through a cooperation request that a total target
power is insufficient, the cooperative relationship with the request destination subsystem will not
be established. In this case, the request sender subsystem requests a subsystem with the next
subsystem number for cooperation, again.
[0077]
15 Note that, in the cooperation request processing, a request sender subsystem may
determine whether or not a total prediction power is equal to or less than a total target power.
In this case, the request sender subsystem obtains the management data of the request destination
subsystem from the data field 10.
COO781
20 A request destination subsystem which received the cooperation request may
modify its own operation plan or nlay disconnect a part of loads, for example. Moreover, in the
request destination subsystem which has established a cooperative relationship, the management
unit 34 may supply electric power to the target facility of the request sender by controlling the
power converter and/or the breaker.
25 [0079]
Moreover, xEMS may request a plurality of other xEMS1s for cooperation. For
example, when xEMS(1) requests xEMS(2) and xEMS(3) for cooperation, a cooperative
relationship among xEMS(l), xEMS(2), and xEMS(3) is established if a total prediction power
of xEMS(1), xEMS(2), and xEMS(3) is equal to or less than a total target power of xEMS(l),
30 xEMS(2), and xEMS(3).
[0080]
According to the above embodiment, the distributed energy management system
can complement energy among the respective subsystems. 111 other words, because subsystems
have a cooperative relationship with each other, even when energy management by one
subsystem alone becomes difficult due to a sudden increase in load or the like, the one subsysteln
cooperates with another subsystem having a surplus energy and these subsystems are regarded as
one subsystem so as to enable the energy management as a total. Thus, the distributed power
sources, such as photovoltaic power generation and rechargeable batteries, can be efficiently
5 utilized. Moreover, the load can be reduced by a subsystem controlling the load, such as air
conditioning or illumination. Moreover, a distributed energy management system interchanges
electric power among subsystems, so that the electric power discharged from a rechargeable
battery and the electric power generated by renewable energy can be efficiently utilized, and the
amount of use of the electric power from a commercial power system can be reduced.
10 [0081]
Moreover, according to the above embodiment, in a large-scale facility, such as a
factory, or in a local community, each subsystem which is a consumer can, in addition to
performing energy management alone, autonomously perform power interchange among
subsystems by cooperating with other subsystems for example when a load increases.
15 Moreover, in achieving such power interchange, each subsystem can interchange electric power
with other subsystems depending on the situations, and can realize the energy management
function as an autonomous distribution type not as a centrally controlled type. Thus, each
subsystem does not need to manage the management data of all the facilities.
[0082]
20 Moreover, FEMS may perform, other than energy cooperation between factories
by FEMS's, energy cooperation throughout a region by cooperating with a building energy
management system, a home energy management system, or the like. In this manner, the
respective subsystems are linked by an autonomous distributed network, so that energy can be
mutually interchanged among factories, buildings, public facilities, and the like each located at a
25 separate place and accordingly the energy management throughout a local community is enabled.
The conventional energy management system performs energy management only within the
system itself, but according to the above embodiment, electric power is enabled to be efficiently
utilized in a large-scale factory and its surrounding region.
[0083]
30 The techniques described in the above embodiment can be expressed as follows.
[0084]
(Expression 1)
A power management device includes: a communication device which transmits
to a communication network first prediction data indicative of a prediction value of a deinandand-
supply balance of electric power of a first facility having a power supply and linking to a
power system, and which, upon receipt of a message to request for power interchange from
another power management device that transmits to the communication network a second
prediction data indicative of a prediction value of a demand-and-supply balance of electric power
5 of a second facility linking to the electric power system, receives the second prediction data from
the communication network; and a determination unit which determines based on the first
prediction data and the second prediction data whether or not the power interchange is possible,
wherein when it is determined that the power interchange is possible, the communication unit
transmits to the another power management device a message to permit the request.
10 [OOSS]
(Expression 2)
A power control system includes: a first power management device which
transmits to a communication network first prediction data indicative of a prediction value of a
demand-and-supply balance of electric power of a first facility having a power supply and
15 linking to a power system; and a second power management device that transmits to the
communication network second prediction data indicative of a prediction value of a demandand-
supply balance of an electric power of a second facility linking to the power system, wherein
the first power management device, upon receipt of a message to request for power interchange
from the second power management device, receives the second predictioil data from the
20 comn~unicationn etwork, determines based on the first prediction data and the second prediction
data whether or not the power interchange is possible, and when it is determined that the power
interchange is possible, the first power management device transmits to the another power
management device a message to permit the request.
[OOSS]
25 (Expression 3)
A power management method includes the steps of: transmitting, by a first power
management device, to a communication network first prediction data indicative of a prediction
value of a demand-and-supply balance of electric power of a first facility having a power supply
and linking to a power system; upon receipt of a message to request for power interchange from
30 a second power management device that transmits to the communication network a second
prediction data indicative of a prediction value of a demand-and-supply balance of electric power
of a second facility linking to the electric power system, receiving, by the first power
management device, the second prediction data from the communication network; and
determining, by a first power management device, based on the first prediction data and the
secoild prediction data, whether or not the power interchange is possible; and when it is
determined that the power interchange is possible, transmitting, by the first power manage~nent
device, to the another power management device a message to permit the request.
[0087]
5 The terminology in these expressions is described. The power management
device corresponds to the energy management system 1 1, the energy management system 16,
and the gateway 17. The power system corresponds to the commercial power system 61 and
the factory power system 62.
REFERENCE SIGNS LIST
10 [OOSS]
10: data field, 1 1, 16: energy management system, 17: gateway, 3 1 :
communication unit, 32: determination unit, 34: management unit, 11 0, 120:
management data, D 1 : common data area, D 1 1, D 12: management data area

WE CLAIM:
[CLAIM 1] A power management device comprising:
a communication unit which transmits to a communication network first
prediction data indicative of a prediction value of a demand-and-supply balance of electric power
of a first facility having a power supply and linking to a power system, and which, upon receipt
of a message to request for power interchange from another power management device that
transmits to the communication network a second prediction data indicative of a prediction value
of a demand-and-supply balance of electric power of a second facility linking to the electric
power system, receives the second prediction data from the communication network; and
a determination unit which determines based on the first prediction data and the
second prediction data whether or not the power interchange is possible, wherein
when it is determined that the power interchange is possible, the communication
unit transmits to the another power management device a message to permit the request.
[CLAIM 2] The power management device according to claim 1, wherein the communication
network is a data field of an autonomous distributed system.
[CLAIM 3] The power management device according to claim 1, wherein the determination
unit calculates a total of the prediction value indicated in the first prediction data and the
prediction value indicated in the second prediction data, and determines based on the total
whether or not the power interchange is possible.
[CLAIM 4] The power management device according to claim 1, wherein the another power
management device determines based on the second prediction data whether or not the request is
necessary, and transmits, when it is determined that the request is necessary, the message to
request for power interchange to the another power management device.
[CLAIM 5]The power management device according to claim 1, wherein the determination
unit calculates the first prediction data based on a prediction value of a power consumption by
the first facility and a prediction value of a supply power by the first facility, and wherein the
another power management device calculates the second prediction data based on a prediction
value of a power consumption by the second facility and a prediction value of a supply power by
the second facility.
[CLAIM 6] The power management device according to claim 1, wherein the first prediction
data indicates a prediction value of a purchased power from the power system by the first facility
and a target value of the purchased power from the power system by the first facility, and
wherein the second prediction data indicates a prediction value of a purchased power from the
power system by the second facility and a target value of the purchased power from the power
system by the second facility.
[CLAIM 7] The power management device according to claim 6, wherein the determination
unit calculates a total prediction power which is a total of the prediction value of the purchased
power from the power system by the first facility and the prediction value of the purchased
power from the power system by the second facility, based on the first prediction data and the
second prediction data, and calculates a total target power which is a total of the target value of
the purchased power from the power system by the first facility and the target value of the
purchased power from the power system by the second facility, and determines, when the total
prediction power is equal to or less than the total target power, that the power interchange is
possible.
[CLAIM 8] A power control system, comprising:
a first power management unit which transmits to a communication network first
prediction data indicative of a prediction value of a demand-and-supply balance of electric power
of a first facility having a power supply and linking to a power system; and
a second power management device which transmits to the communication
network second prediction data indicative of a prediction value of a demand-and-supply balance
of an electric power of a second facility linking to the power system, wherein
the first power management device, upon receipt of a message to request for
power Tnterchang fiom the second power management device, receives the second prediction
data from the communication network, determines based on the first prediction data and the
second prediction data whether or not the power interchange is possible, and wherein
the first power management device transmits, when it is determined that the
power interchange is possible, a message to permit the request to the second power management
device.
[CLAIM 9] A power management method, comprising the steps of:
transmitting, by a first power management device, to a communication network
first prediction data indicative of a prediction value of a demand-and-supply balance of electric
power of a first facility having a power supply and linking to a power system;
upon receipt of a message to request for power interchange from a second power
management device that transmits to the communication network a second prediction data
indicative of a prediction value of a demand-and-supply balance of electric power of a second
facility linking to the electric power system, receiving, by the first power management device,
the second prediction data from the communicatioll network;
determining, by the first power management device, based on the first prediction
2 1
data and the second prediction data whether or not the power interchange is possible; and
when it is deteriniiled that the power interchange is possible, transmitting, by the
first power management device, to the another power management device a message to permit
the request.