ELECTRIC POWER TRANSMISSION FACILITY PLANNING SUPPORT
SYSTEM AND THE METHOD THEREOF
BACKGROUND
The present invention relates to an electric power
transmission facility planning system and the method
thereof for making a facility planning of an electric
power transmission network.
One of background technologies of this technology
10 field is disclosed in Japanese Unexamined Patent
Application Publication No. 2013-126260. This Japanese
Unexamined Patent Application Publication
describes, "Total output determination means determines
whether or not an allowable total output, which is
15 calculated by allowable total output calculation means at
the current time point, goes above the total output of
natural variation power supplies, which is calculated by
total output calculation means at the current time point.
A maximum output command value calculation means
20 calculates the maximum output command value of each
natural variation power supply within a range within which
the total output of the natural variation power supplies
satisfies the allowable total output at the current time
point on the basis of the determination results from the
25 total output determination means, and outputs the maximum
2
output command value to each natural variation power
supply via an output processing means (Refer to ABSTRACT
of this Japanese Unexamined Patent Application
Publication)". In addition, there is Japanese Unexamined
5 Patent Application Publication No. 2004-242411 as a
relevant literature. This Japanese Unexamined Patent
Application Publication describes, "There are provided
selection means that selects a candidate for system
configuration that does not cause a trouble in power
10 feeding at a normal time, and also does not cause a
trouble in power feeding at an assumed accident from a
plurality of system configurations, and an evaluation
value calculation means that calculates the expected value
of a power-failure time, the degree of the deviation of a
15 facility operation rate, and a power transmission loss of
the candidate for system configuration selected by the
selection means as evaluation values. An evaluation
vector lS created on the basis of the three evaluation
values obtained by the evaluation value calculation means,
20 and the degree of supply reliability of the power supply
system is multilaterally evaluated".
SUMMARY
Japanese Unexamined Patent Application Publication
25 No. 2013-126260 discloses the operation method of natural
3
variation power supplies in which the supply power of the
natural variation power supplies becomes the maximum while
the system frequency is kept constant. However,
stabilities that should be evaluated on each bus line such
5 as a voltage stability that is a capability for keeping a
system voltage stable and a synchronization stability that
is a capability for keeping the synchronous operation of a
power supply are not taken into consideration. There may
be assumed a possibility that stability on each bus line
10 becomes problematic owing to the increase of the types of
natural variation power supply and the growing diversity
of the locations of power supplies. Therefore, if only
the system frequency is taken into consideration when
several natural variation power supplies are operated, the
15 instability of the system might occur in some situations.
Japanese Unexamined Patent Application Publication
No. 2004-242411 discloses a method in which the degree of
supply reliability is evaluated using the expected value
of a power-failure time, a power transmission loss, and a
20 facility operation rate, and the effectiveness of facility
investment is evaluated. However, in this Japanese
Unexamined Patent Application Publication, because a
facility investment cannot be evaluated in consideration
of the output control quantities of natural variation
25 power supplies, an effective facility expansion planning
4
for alleviating the output controls of the natural
variation power supplies cannot be drawn out.
Therefore, in the present invention, a probability
distribution that the operation limit of electric power
5 transmission capacity on each bus line becomes equal to a
predefined value or smaller is calculated, and an output
control quantity [Wh] for each power supply is derived
using a means that allocates output controlled power [W]
in that situation to each natural variation power supply.
10 In the present invention, a device, which decides the
location and capacity of an expanded facility on the basis
of a reduced output control quantity [Wh] owing to the
facility expansion and a facility introduction cost, is
provided.
15 In order to solve the abovementioned problem, the
present invention provides an electric power transmission
facility planning support system for materializing
facility planning including the facility expansion of an
electric power transmission network on the basis of the
20 system information of a power system, wherein the electric
power transmission facility planning support system is
characterized by an output control quantity calculation
device for deriving the output control quantities of
natural variation power supplies in consideration of the
25 operation limit value of the electric power transmission
5
network; and a facility expansion planning device for
making the facility planning on the basis of one of the
type, location, and capacity of an electric power
transmission facility in consideration of the output
5 control quantities.
The expansion of an electric power transmission
facility, which is effective for reducing the output
control quantities of natural variation power supplies,
can be planned. The output control quantities after the
10 facility expansion are provided to respective natural
variation power supplies (electric power suppliers).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing an electric power
15 transmission facility planning support system according to
an embodiment of the present invention;
20
FIG. 2 is an explanatory diagram showing data
stored by a generated electric energy DB according to an
embodiment of the present invention;
FIG. 3 is an explanatory diagram showing a
probability distribution of the output of a power supply
stored by a generated electric energy DB according to an
embodiment of the present invention;
FIG. 4 is an explanatory diagram showing a
25 probability distribution of an output variation range
6
stored by a generated electric energy DB according to an
embodiment of the present invention;
FIG. 5 is an explanatory diagram showing data
stored by an operation limit DB according to an embodiment
5 of the present invention;
FIG. 6 is an explanatory diagram showing data
stored by an expanded facility DB according to an
embodiment of the present invention;
FIG. 7 is an explanatory diagram showing input data
10 received by an input device according to an embodiment of
the present invention;
15
FIG. 8 is a graph showing data concerning a power
demand received by an input device according to an
embodiment of the present invention;
FIG. 9 is a block diagram showing a stability
margin calculation unit according to an embodiment of the
present invention;
FIG. 10 is a flowchart showing the processing of a
power supply output decision unit according to an
20 embodiment of the present invention;
FIG. 11 is an explanatory diagram showing the
processing data of a power supply output decision unit
according to an embodiment of the present invention;
FIG. 12 is a flowchart showing the processing of an
25 operation limit comparison unit according to an embodiment
5
7
of the present invention;
FIG. 13 is an explanatory diagram showing the
processing data of an operation limit comparison unit
according to an embodiment of the present invention;
FIG. 14 is a flowchart showing the processing of a
probability calculation unit according to an embodiment of
the present invention;
FIG. 15 is an explanatory diagram showing the
processing data of a probability calculation unit
10 according to an embodiment of the present invention;
FIG. 16 is a flowchart showing the processing of a
control quantity allocation unit according to an
embodiment of the present invention;
FIG. 17 is an explanatory diagram showing the
15 processing data of a control quantity allocation unit
according to an embodiment of the present invention;
FIG. 18 is an explanatory diagram showing the
processing data of a control quantity allocation unit
according to an embodiment of the present invention;
20 FIG. 19 is a flowchart showing the processing of a
facility expansion planning unit according to an
embodiment of the present invention; and
FIG. 20 is an explanatory diagram showing screen
display data according to an embodiment of the present
25 invention.
8
DETAILED DESCRIPTION
Hereinafter, an embodiment will be explained with
reference to the accompanying drawings.
5 First Embodiment
In this embodiment, an example of an electric power
transmission facility planning support system 1, in which
the expansion of an electric power transmission facility
effective for reducing the output control quantities of
10 natural variation power supplies is planned, will be
explained.
15
FIG. 1 is a block diagram showing an electric power
transmission facility planning support system according to
this embodiment.
The electric power transmission facility planning
support system includes: a system information accumulation
device 10; a facility information accumulation device 20;
an input device 30; an output control quantity calculation
device 40; a facility expansion planning device 50; and an
20 output device 60.
25
The system information accumulation device 10
includes: a system configuration DB 101; a facility
constant DB 102; a generated electric energy DB 103; and
an operation limit DB 104.
The system configuration DB 101 stores, for example,
5
9
the locations of electric generators, loads, and
transformer stations, and connection conditions in which
the electric generators, loads, and transformer stations
are connected to electric power transmission lines.
The facility constant DB 102 stores the parameters
of respective facilities which are stored by the system
configuration DB 101. The facility constant DB 102 stores,
for example, information about the impedances and
admittances of the electric power transmission lines, and
10 the reactances of the transformer stations. Furthermore,
the facility constant DB 102 stores the upper limits and
lower limits of active powers that power plants can supply,
and those of reactive powers that the electric generators
can supply. The facility constant DB 102 stores the
15 output adjustment velocities of power plants that can
adjust their output electric energies.
FIG. 2 is an example of data stored by the
generated electric energy DB 103. The generated electric
energy DB 103 stores the type and name of a natural
20 variation power supply, the location and capacity of the
power supply by associating them with each other. In
addition, the generated electric energy DB 103 stores the
probability distributions of outputs of power supplies.
The generated electric energy DB 103 stores the output
25 variation range of each output. The probability
10
distribution of the output of the power supply, and the
probability distribution of the output variation range
depend on a wind condition in the case of a wind power
plant, and depend on the amount of solar radiation in the
5 case of a solar power plant, for example. The probability
distributions of outputs of power supplies, and the
probability distributions of output variation ranges can
be obtained from the values obtained by actual
achievements or values calculated in consideration of the
10 wind conditions or the amounts of solar radiation at the
locations of natural variation power supplies.
FIG. 3 is an example of the probability
distribution of the outputs of a power supply stored by
the generated electric energy DB 103. FIG. 3 is a diagram
15 in which the outputs and the probabilities of the outputs
of a natural variation power supply are plotted. The
probabilities can be directly calculated or can be
calculated from the cumulative operation time of each
output. Alternatively, plural probability distributions
20 associated with times or seasons are stored, and a
suitable probability distribution can be adopted.
FIG. 4 shows an example of the probability
distribution of output variation ranges stored by the
generated electric energy DB 103. FIG. 4 is a diagram in
25 which the output variation ranges and the probabilities of
11
the output variation ranges of the output of a power
supply. The probabilities can be directly calculated or
can be calculated from the cumulative times of the output
variation ranges. Alternatively, plural probability
5 distributions associated with times or seasons are stored,
and a suitable probability distribution can be adopted.
FIG. 5 shoes an example of data stored by the
operation limit DB 104. The operation limit DB 104 stores
the ranges of power flow values within which electric
10 powers can be stably transmitted even if an accident
occurs in a power system. A power flow includes, for
example, the maximum value of an active power and the
maximum value of a reactive power that can be transmitted
on each bus line in a power system, the upper and lower
15 limits of voltage on each bus line, and the upper and
lower limits of the phase difference angle of voltage.
The facility information accumulation device 20
includes an expanded facility DB 201.
FIG. 6 shows an example of data stored by the
20 expanded facility DB 201. The expanded facility DB 201
stores, for example, the types of expanded facility,
capacities, introduction costs, maintenance costs. The
expanded facilities stored by the expanded facility DB 201
are, for example, SVCs, which are phase modifiers, power
25 capacitors, and branch reactors. In this embodiment, the
12
facility expansion means the introduction of phase
modifiers, but it can also mean the expansion or
replacement of electric power transmission lines.
FIG. 7 is an example of input data input into the
5 input device 30. The input device 30 receives power
demands on the relevant system from users. The input
device 30 receives information including, for example, the
location of a consuming region, a date, a time, a power
demand that are associated with each other. The power
10 demand can be a predicted value obtained from past actual
achievements.
15
FIG. 8 is a graph showing power demands received by
the input device 30. FIG. 8 is a graph showing the power
demands per hour which are sorted in descending order.
FIG. 9 shows an example of the block diagram of a
stability margin calculation unit 41.
The output control quantity calculation device 40
includes a stability margin calculation unit 41 and a
controlled power calculation unit 42. The stability
20 margin calculation unit 41 includes a power supply output
decision unit 411 and an operation limit comparison unit
412.
FIG. 10 is a flowchart showing the processing of
the power supply output decision unit 411. Hereinafter,
25 the processing shown in FIG. 10 will be explained while
13
the processing data of the power supply output decision
unit 411 shown in FIG. 11 will be appropriately referred
to.
At step SlOl, the power supply output decision unit
5 411 obtains a system configuration and a facility constant
from the system configuration DB 101 and the facility
constant DB 102 respectively.
At step S102, the power supply output decision unit
411 obtains power demands during a certain time period
10 from the input device 30, and allocates a section number
to a power demand section at each time. The power supply
output decision unit 411 stores section numbers in Row
"DEMAND SECTION", consuming regions in Row "CONSUMING
REGION", and a power demand at each consuming region ln
15 Row "POWER DEMAND". Furthermore, the power supply output
decision unit 411 stores the names of consuming regions,
which are associated with the system configuration DB 101,
in Row "CONSUMING REGION".
At steps S103 to S109, the power supply output
20 decision unit 411 executes loop processing for each demand
section that is a calculation target among the power
demands obtained during the certain time period at step
S102.
At step Sl04, the power supply output decision unit
25 411 obtains the output probability distribution of a
14
natural variation power supply from the generated electric
energy DB 103. Using the season, the date, or the time of
a target demand section as keys, the power supply output
decision unit 411 can obtain the probability distribution
5 of the output of the power supply formed corresponding to
the season, the date, and the time from the generated
electric energy DB 103.
At steps 8105 to SlOB, the power supply output
decision unit 411 executes loop processing for each output
10 within the range of the output probability distribution of
the natural variation power supply obtained at step 8104.
In addition, in this loop processing, the probability of
the output of the selected power supply is obtained from
the output probability distribution, and the probability
15 is stored in Row "OCCURRENCE PROBABILITY" shown in FIG. 11.
At step 8106, the power supply output decision unit
411 decides the output of an output-adjustable power
supply using the target demand section among the power
demands obtained during the constant time period at step
20 8102, the output of the natural variation power supply
selected at step 8103, and the system configuration and
the facility constant obtained at step 8101. The outputadjustable
power supply is, for example, a thermal power
plant. The output of the output-adjustable power supply
25 is decided by the rated power output and the upper and
15
lower limits of the output of the power plant.
Alternatively, the output of the output-adjustable power
supply can be decided using the fuel cost of the plant.
At step S107, the power supply output decision unit
5 411 allocates a power generation pattern number to the
output of each power supply that is decided at steps S105
and S106, and stores the power generation pattern number
in Row "POWER GENERATION PATTERN". Furthermore, the power
supply output decision unit 411 stores respective power
10 supplies including natural variation power supplies and
output-adjustable power supplies in Row "POWER PLANT", and
stores the generated electric energy of each power supply
in Row "OUTPUT OF POWER SUPPLY".
FIG. 12 is a flowchart showing the processing of
15 the operation limit comparison unit 412. Hereinafter, the
processing shown in FIG. 12 will be explained while the
processing data of the operation limit comparison unit 412
shown in FIG. 13 will be appropriately referred to.
The process of step S201 is the same as that of
20 step S101 shown in FIG. 10.
At step S202, the operation limit comparison unit
412 obtains the operation limit value of each bus line
from the operation limit DB 104.
At step S203, the operation limit comparison unit
25 412 obtains a section number from Row "DEMAND SECTION",
16
and a demanded quantity at each consuming region from Row
"POWER DEMAND" and Row "CONSUMING REGION" in FIG. 11 that
shows the calculation results of the power supply output
decision unit 411. In addition, the operation limit
5 comparison unit 412 obtains the occurrence probability of
a power generation pattern from Row "OCCURRENCE
PROBABILITY" in FIG. 11; a power generation pattern number
from Row "POWER GENERATION PATTERN" in FIG. 11; and an
output quantity at each power station from Row "OUTPUT OF
10 POWER SUPPLY" and Row "POWER STATION" in FIG. 11. The
operation limit comparison unit 412 stores the obtained
the demand number of the demanded quantity in Row "DEMAND
SECTION" in FIG. 13; the obtained occurrence probability
of the power generation pattern in Row "OCCURRENCE
15 PROBABILITY" in FIG. 13; and the obtained power generation
pattern number in Row "POWER GENERATION PATTERN" in FIG.
13 respectively.
At steps S204 to S209, the operation limit
comparison unit 412 executes loop processing for each
20 demand section obtained at step S203.
At steps S205 to S208, the operation limit
comparison unit 412 executes loop processing for each
power generation pattern obtained at step S203.
At step S206, the operation limit comparison unit
25 412 executes a power flow calculation using the demand
17
section and the power generation pattern obtained at step
S203, and the system configuration and the facility
constant obtained at step S201. The operation limit
comparison unit 412 stores the calculation results of the
5 power flow calculation in Row "BUS LINE" and Row "ACTIVE
POWER" in FIG. 13 for each bus line. The operation limit
comparison unit 412 stores the number of the bus line
corresponding to the system configuration DB 101 in Row
"BUS LINE", and the active power calculated in the power
10 flow calculation in Row "ACTIVE POWER". Now, in this
embodiment, although only active powers are calculated in
the calculation of the power flow, the operation limit
comparison unit 412 can calculate reactive powers, the
voltages of the bus lines, and the phase difference angles
15 of the bus lines, and can store these values in FIG. 13.
At step S207, the operation limit comparison unit
412 compares the calculation result of the power flow
obtained in step S206 with the operation limit value
obtained in step S202, and calculates stability margins.
20 The operation limit comparison unit 412 obtains a
stability margin, for example, by subtracting the value of
the active power obtained at step S206 from the maximum
value of the active power at the operation limit. The
operation limit comparison unit 412 stores the calculated
25 stability margin in Row "ACTIVE POWER MARGIN" in FIG. 13.
18
Now, in this embodiment just like step S206, although only
the stability margins of the active powers are calculated
ln the calculation, the operation limit comparison unit
412 can calculate the stability margins of reactive powers,
5 the stability margins of the voltages of the bus lines,
and the stability margins of the phase difference angles
of the bus lines, and can store these values in FIG. 13.
Here, although the power supply output decision
unit 411 and the operation limit comparison unit 412
10 derive stability margins by repeating calculations for
respective demand sections and power generation patterns
as described above, they can use a method of directly
calculating stability margins in which, for example, the
relations among the demanded electric energies of
15 consuming regions, the generated electric energies of
power plants, and the relevant stability margins are
approximated by functions and a stability margin to be
obtained is directly derived without calculating a power
flow.
20 The controlled power calculation unit 42 includes a
probability calculation unit 421 and a control quantity
allocation unit 422.
FIG. 14 is a flowchart showing the processing of
the probability calculation unit 421. Hereinafter, the
25 processing shown in FIG. 14 will be explained while the
19
processing data of the probability calculation unit 421
shown in FIG. 15 will be appropriately referred to.
At step S301, the operation limit comparison unit
421 obtains a section number from Row "DEMAND SECTION",
5 and a demanded quantity at each consuming region from Row
"POWER DEMAND" and Row "CONSUMING REGION" in FIG. 11 that
shows the calculation results of the power supply output
decision unit 411. Furthermore, the probability
calculation unit 421 obtains the occurrence probability of
10 a power generation pattern from Row "OCCURRENCE
PROBABILITY" in FIG. 11; a power generation pattern number
from Row "POWER GENERATION PATTERN" in FIG. 11; and an
output quantity at each power station from Row "OUTPUT OF
POWER SUPPLY" and Row "POWER STATION" in FIG. 11.
15 At step S302, the probability calculation unit 421
obtains an active power and an active power margin for
each bus line from Row "ACTIVE POWER", Row "ACTIVE POWER
MARGIN", and Row "BUS LINE" in FIG. 13 that shows the
calculation results of the operation limit comparison unit
20 412.
At steps S303 to S308, the probability calculation
unit 421 executes loop processing for each demand section
obtained at step S302.
At steps S304 to S307, the probability calculation
25 unit 421 executes loop processing for each power
20
generation pattern obtained at step S302.
At step S305, the probability calculation unit 421
obtains the probability distribution of an output
variation range from the power generation DB 103 using the
5 output of a natural power supply obtained at step S301 as
a key.
At step S306, the probability calculation unit 421
calculates a stability margin for each bus line after an
output variation using the demand section and the power
10 generation pattern obtained at step S301, the active power
and the active power margin obtained at step S302, and the
output variation range obtained at step S305.
The probability calculation unit 421 derives an
active power after the output variation for each line by,
15 for example, linearly approximating the relation between
an output variation range and a variation quantity of the
active electric energy for each bus line, and calculates a
stability margin. Because the calculation is executed
with the use of the same demand section, the same system
20 configuration, and the same facility constant, and because
the output variation range is very small in comparison to
the total generated electric energy as well, the value
derived from this linear approximation has a small error.
Alternatively, the probability calculation unit 421
25 can calculate the stability margin after the output
21
variation for each bus line by repeating the power flow
calculation just like the processing of the operation
limit comparison unit 412.
At step S307, the probability calculation unit 421
5 judges whether or not the stability margin after the
output variation for each bus line is equal to or smaller
than a predefined value. For example, when the predefined
value is 0, the stability margin is exceeded owing to the
output variation. If the stability margins of all bus
10 lines are larger than the predefined value, the flow
proceeds to step S309.
At step S308, the probability calculation unit 421
calculates a probability that there exists a bus line
whose stability margin becomes equal to or smaller than
15 the predefined value. The probability calculation unit
421 calculates the probability using the occurrence
probability of the power generation pattern obtained at
step S301 and the probability distribution of the output
variation range obtained at step S305. The probability
20 calculation unit 421 regards the calculated probability as
a probability that the stability margin becomes equal to
or smaller than the predefined value, that is to say, a
probability that the operation limit is exceeded, and
stores the calculated probability in Row "OPERATION LIMIT
25 EXCESS PROBABILITY" in FIG. 15.
22
FIG. 16 is a flowchart showing the processing of
the control quantity allocation unit 422. Hereinafter,
the processing shown in FIG. 16 will be explained while
the processing data of the control quantity allocation
5 unit 422 shown in FIG. 17 and FIG. 18 will be
appropriately referred to.
10
The processes of steps S401 and S402 are the same
as those of steps S201 and S203 shown in FIG. 12
respectively.
At step S403, the control quantity allocation unit
422 obtains a probability that stability becomes equal to
or smaller than the predefined value from Row "OPERATION
LIMIT EXCESS PROBABILITY" shown in FIG. 15 that shows the
calculation results of the power supply output decision
15 unit 411.
At steps S404 to S409, the control quantity
allocation unit 422 executes loop processing for each
demand section obtained at step S402.
At steps S403 to S408, the control quantity
20 allocation unit 422 executes loop processing for each
power generation pattern obtained at step S402.
At step S406, the control quantity allocation unit
422 judges whether or not the operation limit excess
probability is equal to or larger than a predefined value.
25 If the operation limit excess probability is smaller than
23
the predefined value, the control quantity allocation unit
422 makes the flow proceed to step 8407. For example, if
the predefined value is set to 0, it means that things
that have no possibility to exceed the operation limit are
5 brought to the process of step 8408.
At step 8407, the control quantity allocation unit
422 calculates the necessary output controlled power of
each natural variation power supply in order to make the
probability of the operation limit being exceeded smaller
10 than the predefined value. The control quantity
allocation unit 422 obtains an output variation range of
the natural variation power supply which falls within the
operation limit using the relation between the power flow
change of a bus line that exceeds the operation limit and
15 the output variation range of the natural variation power
supply. In addition, the control quantity allocation unit
422 derives the upper limit of the output from the
calculated output variation range.
Alternatively, the control quantity allocation unit
20 422 can calculate the output controlled power of each
natural variation power supply by allocating controlled
power to each natural variation power supply in
consideration of the output variation quantity of each
natural variation power supply, and changing the allocated
25 controlled power bit by bit until the probability of the
24
operation limit being exceeded becomes smaller than the
predefined value.
The control quantity allocation unit 422 stores the
name of each natural variation power supply and the
5 relevant calculated output controlled power in Row
"NATURAL VARIATION POWER SUPPLY" and Row "CONTROLLED
POWER" respectively.
At step 8410, the control quantity allocation unit
422 calculates the expected value of electric energy whose
10 output is controlled using the occurrence probability of
each power generation pattern and the controlled power of
each power generation pattern. The control quantity
allocation unit 422 stores the calculated expected value
of electric energy in Row "EXPECTED VALUE OF TOTAL
15 CONTROLLED ELECTRIC ENERGY" in FIG. 18.
20
The facility expansion planning device 50 includes
a facility expansion planning unit 501.
FIG. 19 is a flowchart showing the processing of
the facility expansion planning unit 501.
At step 8501, the facility expansion planning unit
501 obtains controlled electric energy from Row "EXPECTED
VALUE OF TOTAL CONTROLLED ELECTRIC ENERGY" in FIG. 18 that
shows the calculation results of the control quantity
allocation unit 422 of the facility expansion planning
25 unit 501.
25
At step S502J the facility expansion planning unit
501 obtains facility information from the expanded
facility DB 201. The facility expansion planning unit 501
obtains, for example, the type, capacity, introduction
5 cost, and maintenance cost of an expanded facility as
facility information.
At step 8503, the facility expansion planning unit
501 selects a candidate for expansion planning. The
facility expansion planning unit 501 selects, for example,
10 the type, capacity of the facility, or the location where
the facility is expanded as a candidate for expansion
planning.
The location where the facility is expanded is
selected in consideration of the probability of the
15 operation limit being exceeded that is calculated by the
output control quantity calculation device 40. Expansion
planning effective for stabilizing the system can be
selected by expanding a facility near to a bus line that
has a high possibility of the operation limit being
20 exceeded. The type of facility is selected in
consideration of factors that cause the excess of the
operation limit in the power flow of each bus line. The
factors that cause the excess of the operation limit are,
tor example, the maximum value ot an active power, the
25 maximum value of a reactive power, the upper and lower
26
limits of voltage, and the upper and lower limits of the
phase difference angle of voltage. For example, in the
case where there is a high possibility of the operation
limit being exceeded owing to the upper or lower limits of
5 voltage, it is effective to introduce a power capacitor or
an 8VC that compensate reactive power. A capacity of
facility is selected in consideration of a quantity over
the operation limit in the power flow of each bus line.
At step 8504, the facility expansion planning unit
10 501 calculates controlled electric energy after the
facility expansion. The facility expansion planning unit
501 calculates the controlled electric energy after the
facility expansion by adding the expanded facility to the
system facility DB 101 and the facility constant DB 102
15 and recalculating the controlled electric energy using the
output control quantity calculation device. In the case
where the value of the operation limit DB 104 changes
after the facility expansion, an operation limit value
after the change can be received from the relevant user,
20 or can be obtained by calculation.
At step 8505, the facility expansion planning unit
501 calculates an evaluation value using the cost of the
expanded facility and the controlled electric energy. The
evaluation value can be calculated by multiplying the
25 controlled electric energy by an electric power selling
5
27
cost to calculate a cost corresponding to the controlled
electric energy, and adding the introduction cost and the
maintenance cost of the expanded facility to the cost
corresponding to the controlled electric energy.
At step 8506, the facility expansion planning unit
501 judges whether or not the evaluation value calculated
at step 8505 is equal to or larger than a predefined value.
For example, by setting the predefined value to the
evaluation value before the facility expansion, the
10 evaluation value before the facility expansion and the
15
20
evaluation value after the facility expansion can be
compared with each other. If the evaluation value is
smaller than the predefined value, the facility expansion
planning unit 501 makes the flow proceed to step 8508.
At step 8507, the facility expansion planning unit
501 selects another candidate for the expanded facility
instead of the candidate selected at step 8503. Items to
be changed are, for example, the type, capacity of the
facility, or the location where the facility is expanded.
At step 8508, the facility expansion planning unit
501 outputs the candidate for the facility expansion
selected at step 8503.
FIG. 20 shows an example of the output of the
output device 60. Fig. 20 shows an example of facility
25 expansion planning and an example of output controlled
28
electric energy of natural variation power supplies after
the facility expansion as the processing results of the
facility expansion planning unit 501. The output device
60 outputs, for example, a type of facility, an
5 introduction location of the facility, a capacity of the
facility, an introduction cost of the facility, a
maintenance cost of the facility as facility expansion
planning. The output device 60 outputs a reduced output
control quantity obtained by comparing the output control
10 quantity of each power supply after the facility expansion
with that of each power supply before the facility
expansion as the output controlled electric energy of each
power supply. Alternatively, the output device 60 can
output the processing data of the power supply output
15 decision unit 411 shown in FIG. 11; the processing data of
the operation limit comparison unit 412 shown in FIG. 13;
the processing data of the probability calculation unit
421 shown in FIG. 15; and the processing data of the
control quantity allocation unit 422 shown in FIG. 17 and
20 FIG. 18.
By showing the reduced output control quantity of a
natural variation power supply, the effectiveness on the
alleviation of the output control of the power supply can
be quantitatively evaluated in the deliberation of
25 facility expansion planning.
5
29
By showing the cost of facility expansion and the
reduced output control quantity, the deliberation of the
facility expansion planning can be performed in
consideration of investment effectiveness.
Because cost merit brought about by the reduction
of output control can be evaluated in consideration of an
electric power selling cost or a penalty cost
corresponding to control, the investment effectiveness can
be evaluated in comparison with the cost of the facility
10 expansion.
By showing the reduced output control quantity,
electric power suppliers can show the fairness of the
facility expansion, and furthermore, by quantitatively
showing the effectiveness of the facility expansion, the
15 transparency of the facility expansion can be secured.
With reference to the outputs of the processing
data shown in FIGS. 11, 13, 15, 17, and 18, demand
situations and power generation situations that need the
control of natural variation power supplies are explicitly
20 shown, and these processing results can be utilized for
the operation of the natural variation power supplies.
Here, the present invention is not limited by the
above-described embodiment, and the present invention may
include various modifications. For example, the above-
25 described embodiment is explained in detail for better
30
understanding of the present invention and it is not
always necessary for the present invention to include all
the configurations and elements described above.
List of Reference Signs
5 1 Electric Power Transmission Facility Planning Support
System
10 System Information Accumulation Device
20 Facility Information Accumulation Device
30 Input Device
10 40 Output Control Quantity Calculation Device
50 Facility Expansion Planning Device
60 Output Device

What is claimed is:
1. An electric power transmission facility planning
support system for materializing facility planning
5 including the facility expansion of an electric power
transmission network on the basis of the system
information of a power system, the electric power
transmission facility planning support system comprising:
an output control quantity calculation device for
10 deriving the output control quantities of natural
variation power supplies in consideration of the operation
limit value of the electric power transmission network;
and
a facility expansion planning device for making the
15 facility planning on the basis of one of the type,
location, and capacity of an electric power transmission
facility in consideration of the output control quantities.
2. The electric power transmission facility
20
planning support system according to claim 1,
wherein the output control quantity calculation
device calculates the probability of the operation limit
of the electric power transmission network being exceeded
at the time when the outputs of the natural variation
power supplies vary on the basis of the probability
25 distributions of the outputs and the probability
5
32
distributions of the output variation ranges of the
natural variation power supplies.
3. The electric power transmission facility
planning support system according to claim 1,
wherein the output control quantity calculation
device calculates the output controlled powers of the
natural variation power supplies that are necessary to
keep the power flow of the electric power transmission
network within the operation limit of the network for
10 respective power supplies in consideration of the location
and power flow of the electric power transmission network,
the operation limit of which is exceeded, on the basis of
the probability distributions of the outputs and the
probability distributions of the output variation ranges
15 of the natural variation power supplies.
4. The electric power transmission facility
planning support system according to claim 2 or claim 3,
wherein the output control quantity calculation
device calculates the expected value of the total
20 controlled electric energy of the natural variation power
supplies for respective power supplies on the basis of the
probability of the operation limit of the electric power
transmission network being exceeded and the output
controlled power of each of the natural variation power
25 supplies necessary to keep the power flow within the
33
operation limit.
5. The electric power transmission facility
planning support system according to claim 1,
wherein the facility expansion planning device
5 decides one of the type, location, and capacity of the
expanded facility in consideration of a reduced output
control quantity owing to the facility expansion and the
facility cost.
6. The electric power transmission facility
10 planning support system according to claim 1,
werein the electric power transmission facility
planning support system displays one of the type,
introduction location, capacity, introduction cost, and
maintenance cost of the facility as the facility expansion
15 in consideration of the calculation result of the facility
expansion planning device, and displays an output control
quantity after the facility expansion and a reduced output
control quantity owing to the facility expansion for each
natural variation power supply as the output controlled
20 quantities.
7. An electric power transmission facility planning
support method for materializing facility planning
including the facility expansion of an electric power
transmission network on the basis of the system
25 information of a power system, the electric power
34
transmission facility planning support system comprising
the steps of:
deriving the output control quantities of natural
variation power supplies in consideration of the operation
5 limit value of the electric power transmission network;
and
making the facility planning on the basis of one of
the type, location, and capacity of an electric power
transmission facility in consideration of the output
10 control quanti ties.