JP5540698B2 - Power system plan creation device and power system plan creation method - Google Patents

Description

  The present invention relates to a power system plan creation device and a power system plan creation method.

  In response to so-called liberalization of electric power and deregulation, further reduction in power generation cost is required, and more accurate power plant operation plan and electric power system plan creation technology including a plurality of electric power systems are required.

  For this reason, for example, as Non-Patent Document 1, as the first prior art, an attempt is made to formulate a power generation plan that minimizes the total of fuel costs, start-up costs and interchange (purchase power) costs in consideration of various restrictions. The next day operation planning technology is disclosed.

  As a second conventional technique, a technique disclosed in Patent Document 1 is known. This Patent Document 1 discloses a technology that uses a shortage obtained by subtracting “fixed power” (such as nuclear power) and “variable power” (such as thermal power) from “estimated total demand power” as the total shared power of the secondary battery. It is disclosed.

  In the second prior art, the operation schedule and charge amount of each secondary battery are adjusted as follows. In other words, first of all, we will cover the total power sharing, and further reduce the fuel cost by relaxing the constraints on the variable power (thermal power generator) (flattening the thermal power sharing power). It can be modified to improve efficiency.

JP 2006-94649 A

The Institute of Electrical Engineers of Japan, published on September 20, 2008, “The Journal of the Institute of Electrical Engineers”, Vol. 128 No. 10, 2008), p1227-1234.

  The first prior art described above has the following technical problems. That is, high-performance secondary batteries (especially NAS (sodium sulfur) storage batteries) are being developed, and power systems including secondary batteries are becoming common.

Under such circumstances, both an operation plan for the generator and a charge / discharge plan for the secondary battery are necessary. Since these are related to each other, a plan that takes both into account is necessary.
However, in the above-described first conventional technology, no consideration is given to the operation plan including the secondary battery.

Further, in the case of the above-described second prior art in which the operation plan including the secondary battery is performed, there are still the following technical problems.
That is, when a secondary battery is included in the power system, a NAS battery is often used. However, in the case of a NAS battery, it is necessary to keep it at about 300 ° C. with a heater.

On the other hand, NAS batteries generate heat during discharge and absorb heat during charging.
Even in the case of performing heat insulation, there is room for suppressing useless heating of the heater by considering heat generation and heat absorption of the NAS battery itself.

  Therefore, in the operation of the electric power system including the NAS battery, the heating cost of the heater is taken into consideration, and the generator power generation plan that optimizes (minimizes) the operating cost including the NAS battery heating cost is formulated. There is a need.

However, in the second prior art, a power generation plan and a charge / discharge plan considering the heating cost of the NAS battery have not been performed.
An object of the present invention is to provide a power system planning technique capable of minimizing the cost in consideration of the heater heating cost of the high temperature operation type secondary battery device.

According to a first aspect of the present invention, based on the estimated total demand power of a connected load, an operation plan of the internal combustion power generation apparatus in an electric power system including the internal combustion power generation apparatus and a high-temperature operation type secondary battery device, and A power system planning device for charging and discharging a high-temperature operation type secondary battery,
Constraint item calculation means for calculating a constraint item from information on the operation plan and the charge / discharge plan,
An objective function calculating means for calculating an objective function composed of cost items from information on the operation plan and the charge / discharge plan;
Cost optimization means for obtaining the operation plan and the charge / discharge plan that minimize the objective function that is the sum of the cost items within a range that satisfies the constraint item ,
The cost items include a generator fuel cost required for operating the internal combustion power generation device, a generator startup cost required for starting the internal combustion power generation device, and a heater heating cost for raising the temperature of the high temperature operation type secondary battery device. And a battery charging loss of the high-temperature operation type secondary battery device, and a power purchase cost of the electric power that is exchanged from the outside of the power system.

According to a second aspect of the present invention, based on the estimated total demand power of the connected load, the operation plan of the internal combustion power generation apparatus in the power system including the internal combustion power generation apparatus and the high-temperature operation type secondary battery device, and the A power system planning method for charging and discharging a high temperature operation type secondary battery,
Provided is a power system plan creation method for creating the operation plan and the charge / discharge plan so that the operation cost including the heater heating cost of the high temperature operation type secondary battery device is minimized.

  ADVANTAGE OF THE INVENTION According to this invention, the electric power system plan preparation technique which can minimize the cost which considered the heater heating expense of the high temperature operation type secondary battery apparatus can be provided.

It is a conceptual diagram which shows an example of a structure of the electric power system plan preparation apparatus which implements the electric power system plan preparation method which is one embodiment of this invention. It is a conceptual diagram which shows an example of a structure of the electric power system with which the electric power system plan preparation apparatus which is one embodiment of this invention is applied. It is a flowchart which shows an example of an effect | action of the electric power system plan preparation method and electric power system plan preparation apparatus which are one embodiment of this invention. It is a diagram which shows an example of the heat absorption and heat generation characteristic of the high temperature operation type secondary battery apparatus which comprises the electric power system with which the electric power system plan preparation apparatus which is one embodiment of this invention is applied.

In the present embodiment, as one aspect, a power system plan creation technique including a constraint item calculation unit, an objective function calculation unit, and a cost optimization unit that operate as follows is disclosed.
That is, in the constraint item calculation means, the following supply / demand balance, generator output upper / lower limit, output change rate upper / lower limit, generator minimum continuous stop / operation time, charge / discharge Each restriction item of the lower limit and the upper and lower limit of the storage amount is calculated.

In other words, the supply and demand balance as a constraint item is as follows:
It means maintaining the relationship of estimated total demand power = total power generated by generator + total charge / discharge of storage battery + total purchased power. However, when charging, the charge is negative, and when discharging, the discharge is positive.

The upper and lower limits of the generator output and the upper and lower limits of the output change rate as the restriction items are as follows:
It means maintaining the relationship of the generator power generation lower limit ≦ the generator power generation ≦ the generator power generation upper limit.

The generator minimum continuous stop / operation time as a restriction item is as follows:
Maintaining the relationship of the generator continuous stop time ≧ the generator continuous stop time lower limit, the generator continuous operation time ≧ the generator continuous operation time lower limit. This is a limitation because the generator cannot be stopped so frequently and cannot start for a certain period if it starts operation, and cannot start for a certain period if stopped.

The upper and lower limits of charge / discharge as a restriction item are as follows:
The storage battery charge amount lower limit ≦ the storage battery charge amount ≦ the storage battery charge amount upper limit The storage battery discharge amount lower limit ≦ the storage battery discharge amount ≦ maintaining the battery discharge amount upper limit. Here, the charge amount and the discharge amount indicate the charge amount and the discharge amount per unit time.

The upper and lower limits of power storage amount as a restriction item are as follows:
This means that the relationship of the storage battery storage amount lower limit ≦ the storage battery storage amount ≦ the storage battery storage amount upper limit is maintained. Here, the storage amount indicates the (accumulated) storage amount charged in the storage battery.

  In the objective function calculation means, from the start / stop, power generation output and charge / discharge plan, the following generator fuel cost, generator start-up cost, heater heating cost for NAS battery temperature rise, NAS battery charge loss, power purchase cost (accommodation) The objective function is calculated as the sum of each cost item.

Here, the generator fuel cost is the total sum of the fuel consumption of each generator over the planning target period.
The generator startup cost is the total cost at startup of each generator during the planning period.

The heater heating cost for raising the NAS battery is the total heating cost of the heater for raising the temperature of each storage value to the required temperature during the planning period.
NAS batteries have heat absorption (cooling) during charging, heat generation (warming) during discharge, and heat dissipation (cooling) due to natural heat dissipation.

  On the other hand, the heater installed in the battery is operated so that the temperature of the battery is maintained within the upper and lower limits. As a heater operation method, it is common to start the heater when it falls below this lower limit, and then stop the heater when the upper limit is exceeded, but in order to maintain the temperature at a constant value, PID control, etc. You may perform constant value follow-up control by.

From the storage battery charging / discharging plan, the heat absorption and heat generation of the storage battery and the state of natural heat dissipation are calculated, and the retained heat amount of the storage battery is calculated. The temperature of the storage battery is calculated from the amount of heat stored in the storage battery. For example, when the temperature falls within the upper and lower limits, the heater is started when this temperature falls below the lower limit (set minimum temperature), and then exceeds the upper limit (set maximum temperature). Then, the operation to stop the heater is performed.

  The NAS battery charge loss is the difference between the charge amount accumulated value and the discharge amount accumulated value of each storage battery during the planning target period. Not all of the charge amount (charge amount accumulated value) stored in the storage battery can be discharged, and the portion that cannot be discharged is lost. Specifically, NAS battery charge loss = charge amount accumulated value−discharge accumulated value.

  The power purchase cost (accommodated power) is the purchased power cost when the estimated total demand power is not covered by the generator power generation amount and the storage battery discharge amount, and the shortage is purchased from the outside.

In other words, the total electric power purchased, which is the basis for calculating the purchased electric power cost, is
Total power purchased = Estimated total demand power−Total power generated by generators + Total charge / discharge of storage battery

  Finally, in the cost optimization means, the constraint item calculation means and the objective function calculation means satisfy generators and minimize the objective function (total cost items) while satisfying the constraints as follows. An optimal solution is obtained with the design variable of the discharge plan as the decision variable.

  The optimization method based on the search of the decision variable calculates the constraint condition value and objective function value for the generally set decision variable, and based on the result, the decision variable is generally more optimal than the previous value. The decision variable is adjusted based on some rule that approaches the value. The decision variable approaches the optimal value by repeating the calculation of the constraint condition value and the objective function value again based on the adjusted decision variable and evaluating the result, and the calculated constraint condition value and objective function value are If the optimum condition is satisfied, it is determined that the solution has finally converged to the optimum solution, and the process is terminated.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a conceptual diagram showing an example of the configuration of a power system plan creation device that implements a power system plan creation method according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing an example of a configuration of a power system to which a power system plan creation device according to an embodiment of the present invention is applied.
FIG. 3 is a flowchart showing an example of the operation of the power system plan creation method and the power system plan creation device according to one embodiment of the present invention.

FIG. 4 is a diagram showing an example of the heat absorption and heat generation characteristics of the high temperature operation type secondary battery device constituting the electric power system to which the electric power system planning apparatus according to the embodiment of the present invention is applied.
First, with reference to FIG. 2, the structural example of the electric power grid | system 100 to which the power generation plan production system 200 of this Embodiment is applied is demonstrated.

Power system 100 of the present embodiment includes a power line network 110, a plurality of generators 120 connected thereto _(Ga n), a plurality of NAS battery 130 _(Gb n), the load 140 _(L n), in consists ing.

  Each NAS storage battery 130 (hereinafter may be simply referred to as a storage battery) is provided with a battery heater 131 so that the operating temperature of each NAS storage battery 130 is maintained within a desired temperature range.

In addition, an external power system 180 is connected to the power line network 110 via the power line 181, and it is possible to receive power interchange from the external power system 180 via the power line 181 as necessary.

  Furthermore, in the case of the power system 100 according to the present embodiment, each generator 120 and NAS storage battery 130 are connected to the communication network 150 and started / stopped via the supply / demand control system 170 that is also connected to the communication network 150. The operation such as discharging / charging is controlled.

Further, in the case of the present embodiment, a power generation plan creation system 200 and a database 160 are connected to the communication network 150.
The database 160 stores, for example, information such as the estimated total demand power 300 and the generator / storage battery characteristics 400, and outputs these information to the power generation plan creation system 200 via the communication network 150 or the like as necessary. Is possible.

The power generation plan creation system 200 creates a power system plan such as an operation plan for the generator 120 and a charge / discharge plan for the NAS storage battery 130.
That is, as illustrated in FIG. 1, the power generation plan creation system 200 according to the present embodiment includes an arithmetic device 210, an input unit (not shown) that inputs information to the arithmetic device 210, and the output of information from the arithmetic device 210. It is comprised by the output part which performs.

The power generation plan creation system 200 includes an optimization unit 220, an objective function calculation unit 230, and a constraint condition calculation unit 240 that are realized by the arithmetic unit 210.
That is, the power generation plan creation system 200 is configured by, for example, a computer, the calculation device 210 is configured by a microprocessor, and the functions of the optimization unit 220, the objective function calculation unit 230, and the constraint condition calculation unit 240 are, for example, calculation This is realized by a control program executed by the apparatus 210.

  In the input unit to the arithmetic unit 210, the estimated total demand power 300, the generator / storage battery characteristics 400, etc., which become basic information of the calculation via the communication network 150 or by direct access to the database 160, such as the following: Data is entered.

Then, the generator operation plan value 510 and the storage battery charge / discharge plan value 520 are output from the arithmetic unit 210 to the database 160 as processing results.
The supply and demand control system 170 reads information on the generator operation plan value 510 and the storage battery charge / discharge plan value 520 from the database 160, and performs operation management of the generator 120, the NAS storage battery 130, and the like.

  The supply and demand control system 170 controls the operation of the generator 120 and the NAS storage battery 130 based on the generator operation plan value 510 and the storage battery charge / discharge plan value 520 obtained from the power generation plan creation system 200.

The estimated total demand power 300 input to the power generation plan creation system 200 is information estimated based on information such as past performance in the power line network 110, season, weather, and the like.
On the other hand, in the case of the present embodiment, as an example, the generator / storage battery characteristic 400 includes a generator fuel cost characteristic 410, a generator start-up cost characteristic 420, a generator output upper limit 431, a generator output lower limit 432, and a generator output change. Rate upper limit 441 and generator output change rate lower limit 442, generator minimum continuous stop time 451 and generator minimum continuous operation time 452, storage battery heater characteristic 460, storage battery charge loss characteristic 470, storage battery charge amount upper limit 481 and storage battery charge amount lower limit 482 , Storage battery discharge amount upper limit 483 and storage battery discharge amount lower limit 484, storage battery storage amount upper limit 491 and storage battery storage amount lower limit 492, and further information such as power purchase cost 401 is included.

In the power generation plan creation system 200, the data of the estimated total demand power 300 and the generator / battery characteristics 400 described above are input to the arithmetic device 210, and the arithmetic device 210 calculates constraint conditions and objective function values based on these data. Based on this, an optimization calculation is performed.

  Then, information on the generator operation plan value 510 and the storage battery charge / discharge plan value 520 obtained as a result of the optimization calculation in the arithmetic unit 210 is output through the output unit, via the communication network 150, or directly written in the database 160. Is done.

Hereinafter, the operation of the power generation plan creation system 200 of the present embodiment will be described.
It is an optimization problem to obtain a plan variable that minimizes the objective function (cost item) while satisfying various constraints as in the power system plan creation of the present embodiment.

As described later, this is a mixed integer nonlinear programming problem, and an optimal solution solving method based on a search for a design variable that is a decision variable is effective.
Then, as a solution procedure for the optimization problem based on the search, in this embodiment, the following input process 610, plan variable adjustment process 620, constraint item calculation process 630, objective function calculation process, which are exemplified in the flowchart of FIG. Each process of 640, the result evaluation process 650, and the output process 660 is performed.

  That is, a parameter indicating the condition of the optimization problem is input by “input process 610”, and a value is set to the plan variable value by “plan variable adjustment process 620” (initial value is not initially adjusted but set). Based on the planned variable values, the constraint condition value of the constraint item is calculated by the “constraint item calculation process 630”, and the objective function value as the sum of the cost items is calculated by the “objective function calculation process 640”.

  A search is performed by adjusting the plan variable value in the plan variable adjustment process 620 so that the result is evaluated in the “result evaluation process 650” and the plan variable value approaches a more optimal value. This search is repeated until the constraint condition value and the objective function value satisfy the optimum condition, and the obtained result is output by “output processing 660”.

Hereinafter, each of the processes will be described in detail.
(Input processing 610)
As described above, the input data of the following estimated total demand power 300 and generator / storage battery characteristics 400 is input to the arithmetic unit 210.

  The generator / storage battery characteristics 400 are the attributes / characteristics of the thermal power generator (number, each generator attribute / characteristic: generator fuel cost characteristic 410, generator startup cost characteristic 420, generator output upper limit 431, generator output lower limit 432). Generator output change rate upper limit 441, generator output change rate lower limit 442, generator minimum continuous stop time 451, generator minimum continuous operation time 452, etc.) and storage battery attributes and characteristics (number of units, characteristics of each storage battery: storage battery Heater characteristics 460, storage battery charge loss characteristics 470, storage battery charge amount upper limit 481 and storage battery charge amount lower limit 482, storage battery discharge amount upper limit 483 and storage battery discharge amount lower limit 484, storage battery charge amount upper limit 491, storage battery charge amount lower limit 492, etc.) Information (such as a power purchase cost 401).

(Plan variable adjustment process 620)
Based on the result of the constraint item value and the cost item value calculated by the constraint item calculation process 630 and the objective function calculation process 640, a process of adjusting the plan variable value to be close to the optimum is performed.

(Constraint item calculation process 630)
The constraint item value for the set plan variable value is calculated by the constraint condition calculation means 240.
The plan variable value set here is an initial value or a plan variable value adjusted by the plan variable adjustment processing 620.

(Objective function calculation process 640)
The cost function value for the set plan variable value is calculated by the objective function calculation means 230.
The plan variable value set here is the initial value or the plan variable value adjusted in the plan variable adjustment process 620.

(Result evaluation process 650)
The constraint item calculated in the constraint item calculation process 630 and the cost item calculated in the objective function calculation process 640 are evaluated by the optimization unit 220 and the constraint condition is satisfied or the cost is optimal (minimum). Evaluate whether

(Output processing 660)
The plan value determined to be optimal in the result evaluation process 650 is output from the optimization unit 220 as the optimal generator operation / battery charge / discharge plan (generator operation plan value 510, storage battery charge / discharge plan value 520).

Next, an example of formulation in the optimization problem for creating the power system plan of the present embodiment as described above will be shown.
The planning problem of the operation of the generator 120 and the charging / discharging of the NAS storage battery 130 is formulated by the following planning variables, objective function (objective function calculation means 230), and constraint conditions (constraint condition calculation means 240).

This is an optimization problem including a decision variable that takes a continuous value and a decision variable that takes an integer value and includes an objective function that is nonlinear with respect to the decision variable, and becomes a mixed integer nonlinear programming problem.
In the case of this embodiment, as a plan variable,
Start / stop u _it (0: stop, 1: run) at each time t during the planning target time of each generator i
Whether or not each generator i is activated Δu _i (0: no activation, 1: activation)
Power generation output P _it at each time t during the planning target time of each generator i
Discharge amount HG _it at each time t during the planning target time of each generator i
Charge amount HP _it at each time t during the planning target time of each generator i
There is.
In this case, HG _it and HP _it both take values of zero or more, and HG _it = 0, HP _it > 0 when the NAS storage battery 130 is charged, and HG _it > 0 and HP _it = 0 when discharging.

Objective function (objective function calculation means 230):
The objective function is expressed as follows, and each element is a cost item and is calculated by the objective function calculating means 230.

Objective function = fuel cost (J1) + startup cost (J2) + NAS battery heater cost (J3) + charge loss cost (J4) + power purchase cost (J5)
The fuel cost J1 is expressed by the following formula (1).

Here, a _i , b _i and c _i are parameters determined by the fuel consumption characteristic of the generator i (generator fuel cost characteristic 410).
The start-up cost J2 is expressed by the following formula (2).

Here, SUC _i is a coefficient of the fuel cost characteristic of the generator i.
The NAS battery heater cost J3 is expressed by equation (9) based on the following equations (3) to (8).

  As described above, in order to operate the NAS storage battery 130, it is necessary to keep the battery at a temperature of, for example, 300 ° C. or higher. On the other hand, a storage battery has a characteristic of absorbing heat during charging and generating heat during discharging. Considering this, the amount of heat stored in the storage battery is calculated as follows.

It denotes the charge and discharge amount at the time t of the battery i in one variable E _{it. Eit} takes a negative value at the time of charging, takes a positive value at the time of discharging, and is expressed as follows using the above-mentioned symbols.

A variable representing the amount of heat generated per unit time at time t of the storage battery i is ΔQ _it (ΔQ _it is a variable common to exothermic heat absorption, and takes a positive value during heat generation and a negative value during heat absorption). The relationship between E _it and ΔQ _it is shown in the diagram of FIG. 4 together with the heat generation characteristics and the heat absorption characteristics during charging.

Such heat absorption / heat generation characteristics are expressed as a table or graph in which the heat absorption / heat generation amount ΔQ _it is determined corresponding to each value E _it of charge / discharge, but in the present embodiment, this is regarded as a function, Is expressed as the following equation (4).

Since this characteristic is considered to be determined for each storage battery i, the function f _i is also determined for each battery, so the index i is attached.
Next, let RD _it be the amount of heat per unit time that escapes from the storage battery i by natural heat radiation at time t.

RD _it is may be a constant value regardless of the example time may be considered a model such as the heat radiation in proportion to the difference between the battery temperature and the ambient temperature (absolute value of) occurs.
When it is considered that a certain value of heat dissipation occurs, it is defined as the following equation (5).

The amount of heat Q _it stored in the storage battery i by time t is expressed by the following equation (6).

Here, Q _i0 is an initial value of the retained heat amount of the storage battery i.
Next, the temperature T _it of the storage battery i at time t is calculated as in the following equation (7).

Here M _i is the mass of the battery i.
Battery heater 131 is assumed to be installed for each battery, start and stop of the accumulator i is based on the temperature T _it of the battery i, is defined as follows.

Here, it is assumed that the battery heater 131 takes only two states of starting (operation) or stopping, and the battery heater 131 consumes a certain amount of energy such as electric power during operation and generates a certain amount of heat. The operation stop of the battery heater 131 is determined according to the temperature of the storage battery. For example, the battery heater 131 starts to operate when the temperature falls below the set minimum temperature T _it ^min , and then stops when the set maximum temperature T _it ^max is reached. To do.

Shutdown state _{h it} of the battery heater 131 of the storage battery i is at time t,

Calculated by
When the energy consumption during heater operation of the storage battery i and F _i, the energy consumption in the time t is expressed as F _i h _it.

  Therefore, by summing up each storage battery in the evaluation target period, the cost of the battery heater 131 (NAS battery heater cost J3) is expressed by the following equation (9).

  Further, the charge loss cost J4 is expressed by the following formula (10).

This equation (10) represents the charge amount accumulated value (absolute value) −discharge amount accumulated value (absolute value), and corresponds to the charge loss.
The power purchase cost J5 is expressed by the following equation (11).

Here, R _t : power purchase amount at time t, k: power purchase unit price.
The function value of the objective function is calculated as the sum of the above cost items.
Next, the constraint conditions will be described.

Constraint conditions (constraint condition calculation means 240):
The constraint conditions are expressed as follows, and each item is calculated by the constraint condition calculation means 240.

[Supply and demand balance]:
If D _{t is the} estimated total demand power, the relationship of the following formula (12) needs to be maintained at each point in the planning target period.

  [Generator output upper and lower limits, output change rate upper and lower limits]:

However,
P _i ^min : Output lower limit value of generator i (generator output lower limit 432)
P _i ^max : Output upper limit value of generator i (generator output upper limit 431)
It is.

However,
ΔP _i ^downmax : descent-side maximum change rate of generator i (generator output change rate lower limit 442)
ΔP _i ^upmax : Maximum increase rate of generator i on the rising side (generator output change rate upper limit 441)
It is.
[Generator minimum continuous stop / operation time]:

However, mint _{i is} the minimum continuous stop time of the generator i (the minimum generator continuous stop time 451).

Where minr _{i is} the minimum continuous operation time of the generator i (the minimum generator continuous operation time 452).
[Charging / discharging upper and lower limit]:
At each time point in the planning target period and each storage battery, there are constraints expressed by the following formulas (17) and (18) as constraints on the upper and lower discharge amounts.

However, in Formula (17) and Formula (18),
HG _i ^min : discharge amount lower limit value of storage battery i (storage battery discharge amount lower limit 484)
HG _i ^max : discharge amount upper limit value of storage battery i (storage battery discharge amount upper limit 483)
HP _i ^min : Charge amount lower limit value of storage battery i (storage battery charge amount lower limit 482)
HP _i ^max : Charge amount upper limit value of storage battery i (storage battery charge amount upper limit 481)
It is.

Here, the charge amount and the discharge amount indicate the charge amount and the discharge amount per unit time.
[Capacity limit]:
In each storage battery at each time point in the planning target period, there is a restriction expressed by the following formula (19) as a restriction on the upper and lower limits of the amount of electricity stored.

However, in this formula (19),
LH _i ^min : Storage battery lower limit value of storage battery i (storage battery storage capacity lower limit 492)
LH _i ^max : The storage amount upper limit value of the storage battery i (storage battery storage amount upper limit 491)
It is.

Here, the storage amount indicates the (accumulated) storage amount charged in the storage battery.
(Solving optimization problems)
As an optimization problem solution (optimization process) based on the search described in the flowchart of FIG. 3 described above, the optimization unit 220 can use, for example, a metaheuristic technique.

Specifically, Genetic Algorithm (GA) and its improved method, Simulated Annealing (SA) and its improved method, Tab Search (hereinafter referred to as TS) and its improved method, and Particle Swarm Optimization (hereinafter referred to as PSO) Such improved techniques can be used.

As described above, according to the present embodiment, the following effects are obtained.
In other words, in the conventional generator operation / storage battery charging / discharging plan, the operation cost of the heater in the NAS battery is not considered, and the heater of the NAS battery is operated depending on it, and the heater is unnecessarily operated. May become inefficient due to driving.

  On the other hand, in the case of the present embodiment, the cost of the battery heater 131 is covered by making a generator power generation / storage battery charging / discharging plan considering the operation of the battery heater 131 provided in the NAS storage battery 130. The operation cost is reduced, and the generator power generation / storage battery charging / discharging in the electric power system 100 is optimally and efficiently performed as a whole, thereby reducing the cost and simultaneously reducing the environmental load.

  That is, since the NAS storage battery 130 generates heat during discharging and absorbs heat during charging, the battery heater 131 can also be used by considering the heat generation and heat absorption of the NAS storage battery 130 even when the temperature is increased and maintained by heating by the battery heater 131. It is possible to suppress unnecessary heating.

  In addition, a power generation plan for a generator that can realize optimization (minimization) of operation costs including heating costs of the battery heater 131 by charging and discharging in consideration of heat absorption and heat generation of the NAS storage battery 130 itself is formulated. Can do.

Needless to say, the present invention is not limited to the configuration exemplified in the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the high temperature operation type secondary battery device is not limited to a NAS (sodium sulfur) storage battery device, but can be widely applied to secondary batteries that require heating by a heater during operation.

DESCRIPTION OF SYMBOLS 100 Power system 110 Power line network 120 Generator 130 NAS storage battery 131 Battery heater 140 Load 150 Communication network 160 Database 170 Supply and demand control system 180 External power system 181 Power line 200 Power generation plan creation system 210 Arithmetic unit 220 Optimization means 230 Objective function calculation means 240 Constraint condition calculation means 300 Estimated total demand power 400 Generator / storage battery characteristics 401 Power purchase cost 410 Generator fuel cost characteristics 420 Generator start-up cost characteristics 431 Generator output upper limit 432 Generator output lower limit 441 Generator output change rate upper limit 442 Power generation Machine output change rate lower limit 451 Generator minimum continuous stop time 452 Generator minimum continuous operation time 460 Battery heater characteristic 470 Battery charge loss characteristic 481 Battery charge upper limit 482 Battery charge lower limit 483 Battery discharge upper limit 48 Storage battery discharge amount lower limit 491 Storage battery storage amount upper limit 492 Storage battery storage amount lower limit 510 Generator operation plan value 520 Storage battery charge / discharge plan value 610 Input process 620 Plan variable adjustment process 630 Constraint item calculation process 640 Objective function calculation process 650 Result evaluation process 660 Output Processing J1 Fuel Cost J2 Startup Cost J3 NAS Battery Heater Cost J4 Charge Loss Cost J5 Power Purchase Cost

Claims (4)

Based on the estimated total demand power of the connected load, the operation plan of the internal combustion power generation device in the power system including the internal combustion power generation device and the high temperature operation type secondary battery device, and charging and discharging of the high temperature operation type secondary battery A power system planning device for planning,
Constraint item calculation means for calculating a constraint item from information on the operation plan and the charge / discharge plan,
An objective function calculating means for calculating an objective function composed of cost items from information on the operation plan and the charge / discharge plan;
Cost optimization means for obtaining the operation plan and the charge / discharge plan that minimize the objective function that is the sum of the cost items within a range that satisfies the constraint item,
The cost item is
Generator fuel cost required for operation of the internal combustion power generator,
Generator starting cost required for starting the internal combustion power generator,
The heater heating cost for raising the temperature of the high temperature operation type secondary battery device,
Battery charge loss of the high temperature operation type secondary battery device,
The power purchase cost of the electric power that the electric power system has exchanged from the outside,
An electric power system plan creation device characterized by including. Based on the estimated total demand power of the connected load, the operation plan of the internal combustion power generation device in the power system including the internal combustion power generation device and the high temperature operation type secondary battery device, and charging and discharging of the high temperature operation type secondary battery A power system planning method for planning,
A power system plan creation method, wherein the operation plan and the charge / discharge plan are created so that an operation cost including a heater heating cost of the high temperature operation type secondary battery device is minimized. In the electric power system plan preparation method of Claim 2 ,
The high-temperature operation type secondary battery device is a NAS (sodium sulfur) storage battery device.   Based on the estimated total demand power of the connected load, the operation plan of the internal combustion power generation device in the power system including the internal combustion power generation device and the high temperature operation type secondary battery device, and charging and discharging of the high temperature operation type secondary battery A power system planning device for planning,
  An electric power system plan creation device comprising means for creating the operation plan and the charge / discharge plan so that an operation cost including a heater heating cost of the high temperature operation type secondary battery device is minimized.