Method for creating operation plan for storage battery and operation plan creation assistance device

Abstract

Provided is a method that makes is possible to efficiently confirm an operation plan for a storage battery when providing a priority period. The present invention is configured so that a plurality of first simulations in which a battery condition has different values at the start of a priority period are performed to determine whether operation is feasible in each first simulation, a first range in which the battery condition should be satisfied at the end of a preceding period and a second range in which the battery condition should be satisfied at the start of a subsequent period are specified on the basis of the simulation results indicating feasibility, a second simulation is performed only for the preceding period, an operation plan in the preceding period is corrected when a result indicating that the first range is not satisfied is obtained, two third simulations are performed only for the subsequent period with each of two boundary conditions in the second range serving as an initial value of the battery condition, and the operation plan in the subsequent period is corrected when a simulation result indicating that operation is not feasible in the subsequent period is obtained in at least one of the two third simulations.

Description

Method for Creating Operation Plan of Storage Battery and Operation Plan Creation Support Device

[0001] The present invention relates to the creation of an operation plan for a storage battery, and particularly to processing in the case of providing a preferential period.

[0002] Retail electric power providers that procure electric power from the electric power market and retail it to consumers often formulate a power supply and demand plan for a planning target period of several days to about two weeks (e.g., two weeks) from a certain planning date.

[0003] Also, the formulation of an operation plan for a power generation facility in a power generation business operator that generates power using renewable energy, and the formulation of an operation plan for a power storage system in a power storage business operator that has a sodium-sulfur battery or other storage battery are also carried out for a period of about two weeks, similar to the formulation of a supply and demand plan by a retail electric power provider. Note that a retail electric power provider may also act as a power generation business operator and a power storage business operator.

[0004] However, since the predicted value of the electric power market price changes daily with changes in the power supply and demand situation, weather conditions, fuel prices, the operating status of power generation facilities, etc., the operation plan that can expect high profits can also change daily. Therefore, it is desirable that the operation content after the day following the planned date in the operation plan formulated on a certain planning date be reviewed when formulating a supply and demand plan for a planning target period that is shifted by one day from the planning target period at the time of the previous day.

[0005] Also, when the use of the power storage system by the power storage business operator aims to obtain profits by trading the charge and discharge power of the power storage system in the electric power market, the operation plan of the power storage system is usually formulated so that charging is performed when the market price is low and discharging is performed when the market price is high in order to obtain high profits.

[0006] To formulate an operation plan for the power storage system that maximizes profits based on the predicted value of the electric power market price, it is necessary to create several candidate operation plans and adopt the optimal operation plan from them.

[0007] However, the operation plan for the energy storage system must be formulated so that the remaining capacity and temperature (battery temperature) of the storage battery remain within a predetermined allowable range when the operation plan is executed. A guidance device is already known that determines whether or not to adopt an operation plan from this perspective based on the results of a simulation targeting the operation plan, and prompts a change in the plan if it is not suitable (see, for example, Patent Document 1).

[0008] If the operational plan is changed, the simulation will also need to be redone. Due to constraints such as the closing time of the advance market, the time required to change the output of power generation facilities, and the time required to curb demand, it is desirable that changes to the operational plan, including simulations, be made as quickly as possible.

[0009] However, with conventional methods, it was necessary to perform a full simulation over the entire period covered by the investment plan. Even if only a part of the investment plan was changed, it was necessary to redo the simulation for the entire period covered by the plan, making it difficult to flexibly change the investment plan.

[0010] Furthermore, as one form of reviewing the operation plan for an energy storage system, it may be necessary to determine the operation schedule for a specific period within a planned period (for example, one week from now) in advance of the operation schedule for earlier periods, and to ensure that the operation of the energy storage system in accordance with that schedule is carried out reliably (with a higher priority than other periods).

[0011] Such situations might include, for example, when a battery storage business leases its battery storage system to another party for a period (operating it according to an operational plan formulated by the other party for a certain period), when a battery storage business has entered into a contract with another party to sell (discharge) or buy (charge) electricity using the battery storage system at a fixed time several days in advance, when market prices are expected to rise due to a tight supply and demand for electricity, or when market prices are expected to fall sharply due to an electricity surplus.

[0012] In such cases, conventionally, a certain period immediately preceding a priority period (a period during which the operational plan must be reliably implemented) was sometimes set as a pause period during which charging and discharging were not performed, in order to stabilize the battery temperature at that time. However, from the standpoint of battery operational efficiency, it is preferable to avoid pause periods as much as possible.

[0013] Furthermore, with conventional methods, even if the planned period included priority periods or even periods of inactivity, it was necessary to redo the simulation for the entire planned period.

[0014] Patent No. 5096018

[0015] This invention has been made in view of the above-mentioned problems, and aims to provide a method for efficiently determining the operation plan of a storage battery when a priority period is set.

[0016] To solve the above problems, a first aspect of the present invention is a method for creating an operation plan for a storage battery that includes a priority period as part of a planned period, comprising: a planning step of creating an operation plan for a storage battery in which a schedule for charging and discharging the storage battery in a predetermined planned period is set for each unit time, a part of the planned period is set as a priority period, and the planned period is comprised of the priority period, a preceding period preceding the priority period, and a succeeding period following the priority period; a priority period processing step of performing multiple first simulations, each with a different value of the battery condition, which is an indicator of the state of the storage battery, at the start of the priority period, focusing only on the priority period of the operation plan, determining for each of the multiple first simulations whether the operation plan can be operated in the priority period, and if there is no operation plan that is determined to be operable in the priority period, modifying the operation plan and repeating the multiple first simulations; and a priority period processing step of determining whether the operation plan can be operated in the priority period obtained in the priority period processing step The invention is characterized by comprising: a battery condition identification step of identifying a first range that the battery conditions should satisfy at the end of the preceding period and a second range that the battery conditions should satisfy at the start of the subsequent period, based on the simulation results; a preceding period processing step of performing a second simulation targeting only the preceding period of the operation plan, and if the simulation result obtained is that the operation plan in the preceding period is not feasible, or if the result obtained is that the first range is not satisfied, modifying the operation plan in the preceding period and repeating the second simulation; and a subsequent period processing step of performing two third simulations targeting only the subsequent period, using each of the two boundary conditions in the second range as the initial value of the battery conditions, and if the simulation result obtained in at least one of the two third simulations is that the operation plan in the subsequent period is not feasible, modifying the operation plan in the subsequent period and repeating the third simulation.

[0017] A second aspect of the present invention is a method for creating an operation plan for a storage battery according to the first aspect, wherein the battery conditions are the remaining capacity and temperature of the storage battery, in the battery condition identification step, a first range and a second range are identified for the remaining capacity and the temperature, respectively, in the preceding period processing step, if the first range for either the remaining capacity or the temperature is not met, the operation plan for the preceding period is modified, and in the succeeding period processing step, two types of boundary conditions are determined based on the combination of the second ranges for the remaining capacity and the temperature, respectively.

[0018] A third aspect of the present invention is a method for creating an operation plan for a storage battery according to the second aspect, characterized in that, in the battery condition identification step, among the battery conditions at the start of the priority period used in the plurality of first simulations, the range of the remaining capacity between the minimum and maximum values ​​and the range of the temperature between the minimum and maximum values ​​in the battery conditions that yielded a simulation result indicating that the operation plan can be implemented during the priority period are identified as the first range for the remaining capacity and the temperature, respectively.

[0019] A fourth aspect of the present invention is a method for creating an operation plan for a storage battery according to the second or third aspect, characterized in that, in the battery condition identification step, the range of the remaining capacity at the end of the priority period and the range of the temperature at the end of the priority period of the simulation in which the result obtained that the operation plan can be operated during the priority period from among the plurality of first simulations is specified as the second range for the remaining capacity and the temperature, respectively.

[0020] A fifth aspect of the present invention is an apparatus for creating an operation plan for a storage battery, comprising: an operation plan creation unit that creates and modifies an operation plan for a storage battery, which sets a schedule for charging and discharging the storage battery for each unit of time during a predetermined planning period; a simulation execution unit that can execute a simulation targeting the operation plan for the storage battery; and a determination processing unit that determines whether or not the operation plan is feasible based on the results of the simulation, wherein in the operation plan, a priority period is set for a part of the planning period, and the planning period consists of the priority period, a preceding period preceding the priority period, and a subsequent period following the priority period, the simulation execution unit can execute a first simulation targeting only the priority period, a second simulation targeting only the preceding period, and a third simulation targeting only the subsequent period, and the determination processing unit determines the feasibility of the operation plan in the priority period, the preceding period, and the subsequent period, respectively, based on the results of the first simulation, the second simulation, and the third simulation, The feasibility of operation can be determined, and the simulation execution unit performs multiple first simulations with different values ​​for the battery conditions, which are an indicator of the state of the storage battery, at the start of the priority period, and the determination processing unit determines for each of the multiple first simulations whether the operation plan can be operated during the priority period, and if there is no operation plan for which operation is determined to be possible during the priority period, the operation plan creation unit modifies the operation plan, and the simulation execution unit repeats the first simulation, and if a simulation result is obtained in the multiple first simulations that the operation plan can be operated during the priority period, the simulation execution unit identifies a first range that the battery conditions should satisfy at the end of the preceding period and a second range that they should satisfy at the start of the succeeding period based on the simulation result, and the simulation execution unit executes the second simulation once the first range and the second range have been identified, and the determination processing unit determines, based on the result of the second simulation,The system determines whether the operation plan can be implemented during the preceding period and whether the battery conditions satisfy the first range at the end of the preceding period. If a simulation result indicates that the operation plan cannot be implemented during the preceding period, or if the first range is not satisfied, the system causes the operation plan creation unit to modify the operation plan for the preceding period and then causes the simulation execution unit to repeat the second simulation. The simulation execution unit performs two types of third simulations, using each of the two boundary conditions in the second range as the initial value of the battery conditions. Based on the results of the two types of third simulations, the system determines whether the operation plan can be implemented during the subsequent period. If at least one of the two types of third simulations indicates that the operation plan cannot be implemented during the subsequent period, the system causes the operation plan creation unit to modify the operation plan for the subsequent period and then causes the simulation execution unit to repeat the third simulation.

[0021] A sixth aspect of the present invention is an operation plan creation support device according to the fifth aspect, wherein the battery conditions are the remaining capacity and temperature of the storage battery, the determination processing unit specifies a first range and a second range for the remaining capacity and the temperature, and if the first range for either the remaining capacity or the temperature is not met, the operation plan creation unit modifies the operation plan for the preceding period, and determines the two types of boundary conditions based on the combination of the second ranges for the remaining capacity and the temperature.

[0022] A seventh aspect of the present invention is an operation plan creation support device according to the sixth aspect, characterized in that the determination processing unit identifies the range of the remaining capacity between the minimum and maximum values ​​and the temperature between the minimum and maximum values, respectively, as the first range for the remaining capacity and the temperature, among the battery conditions at the start of the priority period used in the plurality of first simulations, which resulted in a simulation result indicating that the operation plan can be implemented during the priority period.

[0023] An eighth aspect of the present invention is an operation plan creation support device according to the sixth or seventh aspect, characterized in that the determination processing unit identifies the range of the remaining capacity at the end of the priority period, which is between the minimum and maximum values ​​of the remaining capacity and the range of the temperature at the end of the priority period, as the second range for the remaining capacity and the temperature, respectively, for the simulation in which the result obtained that the operation plan can be implemented during the priority period among the plurality of first simulations.

[0024] According to the first to eighth aspects of the present invention, when setting a priority period in the battery operation plan to ensure that charging and discharging are carried out as planned, it is possible to create an operation plan including the priority period more efficiently than in the conventional method of determining the feasibility of the operation plan based on the results of a simulation throughout the planned period. Furthermore, depending on the battery condition range at the start and end of the priority period, it is possible to omit the idle period, which was substantially essential to set in the conventional method. Therefore, it is possible to utilize the battery with higher utilization efficiency than in the conventional method.

[0025] Figure 1 is a diagram showing the schematic configuration of a battery storage system 100 according to an embodiment of the present invention. Figure 2 is a block diagram showing the functional components of the battery storage control device 10 and the operation guidance device 11. Figure 3 is a diagram showing the basic flow of the simulation. Figure 4 is a diagram for specifically explaining the creation of a daily operation plan and the simulation associated therewith. Figure 5 is a diagram for explaining a conventional processing method when a priority period is set. Figure 6 is a diagram showing an example of the state change of the battery storage system 100B during the priority period and the preceding preceding period when no downtime period IA1 is provided. Figure 7 is a diagram showing the processing procedure in this embodiment when a priority period is set in the middle of the planned period. Figure 8 is a diagram for explaining the processing method adopted in this embodiment when a priority period is set. Figure 9 is a diagram showing an example of the state change of the battery storage system 100B when simulation results are obtained in which the SOC and battery temperature are kept within an acceptable range. Figure 10 is a diagram showing an example in which the battery condition range at the start of the priority period is satisfied by modifying the operation plan for the preceding period.

[0026] <Battery System> Figure 1 is a diagram showing a schematic configuration of a battery system 100 according to an embodiment of the present invention. The battery system 100 mainly comprises a battery 100B and a battery control system 100C.

[0027] The storage battery 100B is configured as a module string in which a number of module batteries 12 are connected in series. However, in Figure 1, only one module battery 12 is shown for the sake of simplicity in the illustration. Alternatively, the storage battery 100B may be configured with only one module battery 12.

[0028] Each module battery 12 generally has a configuration in which a battery array 13, which is composed of multiple individual cells (not shown), is built into the housing.

[0029] Each module battery 12 is further equipped with a fan 14 and a heater 15 as temperature maintenance means to maintain the temperature of the module battery 12 within a certain operating range during operation. Furthermore, a temperature sensor 16 for measuring the temperature of the module battery 12 is also provided. Note that multiple temperature sensors 16 may be arranged on a single module battery 12.

[0030] A single cell is, for example, a sodium-sulfur cell (NaS cell) in which sulfur is the positive electrode active material and metallic sodium is the negative electrode active material. When a single cell is an NaS cell, an exothermic reaction occurs in each cell in which metallic sodium and sulfur react to produce sodium polysulfide, and the temperature of the module cell 12 rises accordingly. However, there are limits to the heat resistance of the components of the NaS cell, particularly the solid electrolyte tube, the aluminum container, the α-alumina insulating ring interposed between them when they are joined, and the glass joints, TCB joints, and aluminum welds that seal these components. Furthermore, if these components are in contact with highly chemically active sodium, sulfur, sodium polysulfide, etc., at high temperatures for a long period of time, corrosion and degradation are likely to occur. Therefore, it is undesirable for the temperature of the single cell to exceed a certain value due to the continuation of discharge, i.e., the continuation of the above-mentioned exothermic reaction.

[0031] On the other hand, the conductivity of sodium ions to β-alumina, which is a solid electrolyte, and the conductivity of sulfur, which is an anode active material, and the sulfur-impregnated graphite felt, increase with increasing temperature. In other words, the higher the temperature due to the heat generated by discharge, the lower the internal resistance of the module battery 12. Therefore, when the single cell is a NaS battery, it is preferable to operate the module battery 12 at a high temperature in terms of charge-discharge efficiency. Moreover, considering the diffusivity of the active material at the anode and the equilibrium of the exothermic reaction during discharge, operation at low temperatures is disadvantageous in terms of charge recovery.

[0032] Taking into account the utilization of heat generated by the exothermic reaction during discharge, as well as the limitations imposed by the characteristics of the materials and components constituting the NaS battery, when the single cell is a NaS battery, the module battery 12 is generally operated within a predetermined operating temperature range selected from a temperature range of 280°C to 350°C.

[0033] Alternatively, prioritizing the reduction of the battery's internal resistance or improving its charge-discharge recovery performance, the operating temperature range of the module battery 12, which consists of NaS cells, may be set to 305°C to 360°C.

[0034] Each module battery 12 is configured as described above, and the resulting module string is connected to the DC side of a known PCS (AC-DC converter: Power Conversion System) via a charge / discharge current detector (neither is shown). The charge / discharge current detector is for measuring the charge / discharge current flowing through the battery 100B. The AC side of the PCS is connected to a load or external system via a transformer.

[0035] The battery control system 100C mainly comprises a battery control device 10 that controls the operation of the battery 100B, and an operation guidance device 11 that handles processes related to the operation of the battery 100B, such as creating and simulating operation plans for the battery 100B. In other words, in this embodiment, the operation guidance device 11 functions as an operation plan creation support device that assists in creating operation plans for the battery 100B.

[0036] In this embodiment, the battery control device 10 controls the charging and discharging operation and temperature (battery temperature) of each module battery 12. More specifically, the battery control device 10 controls the PCS, thereby controlling the charging and discharging operation of the module string composed of numerous module batteries 12, and the battery control device 10 controls the fan 14 and heater 15 of each module battery 12, thereby controlling the battery temperature. Figure 2 is a block diagram showing the functional components of the battery control device 10 and the operation guidance device 11.

[0037] The battery control device 10 can be implemented using a general-purpose or dedicated computer (control computer) equipped with a CPU, memory, storage, etc. A predetermined program stored in the storage is loaded into the CPU and executed, and the battery control device 10 mainly comprises a charge / discharge schedule acquisition unit 1, a charge / discharge control unit 2, a heater control unit 3, and a heat dissipation control unit 4 as functional components.

[0038] The charge / discharge schedule acquisition unit 1 acquires the charging and discharging schedule (charge / discharge schedule) for the storage battery 100B and provides the charge / discharge schedule to the charge / discharge control unit 2, the heater control unit 3, and the heat dissipation control unit 4.

[0039] In this embodiment, the term "charge / discharge schedule" refers to the operational plan (operational plan) related to the charging and discharging schedule of the battery 100B, which is created by the battery control system 100C or externally, and which has been determined to be the operational plan to be executed by the battery 100B.

[0040] The charge / discharge schedule includes, for example, the start and end times for charging and discharging, the output during discharging, the amount of charge during charging, and the operating temperature range.

[0041] The charge / discharge control unit 2 controls the charging and discharging operations of the battery 100B according to the contents of the charge / discharge schedule. Generally, when the discharge start time described in the charge / discharge schedule arrives, the charge / discharge control unit 2 connects the battery 100B to the outside and starts discharging from each module battery 12 to the outside. Then, when the discharge end time arrives, it disconnects the battery 100B from the outside and ends the discharge. Similarly, when the charge start time described in the charge / discharge schedule arrives, it connects the battery 100B to the outside and starts charging the battery 100B from the outside. Then, when the charge end time arrives, it disconnects the battery 100B from the outside and ends the charging of each module battery 12 from the outside.

[0042] The control of the charging and discharging operations of the storage battery 100B by the charge-discharge control unit 2 is performed by managing the depth of discharge of the entire storage battery 100B. The depth of discharge is an index indicating the degree of discharge in the individual cells that make up the collective battery 13 of the module batteries 12 in the storage battery 100B. When the depth of discharge is 0%, the module battery 12 is at the end of charging, and when the depth of discharge is 100%, the module battery 12 is at the end of discharge.

[0043] However, when a plurality of module batteries 12 are connected in series to form a module string, the depth of discharge of the individual cells that make up the collective battery 13 in each module battery 12 is generally uniform. Therefore, in the present embodiment, the depth of discharge of the entire storage battery 100B is represented by a single common value, and this value is referred to as the depth-of-discharge management value.

[0044] In principle, the charge-discharge control unit 2 sets the depth of discharge when the storage battery 100B reaches the end of charging to 0%, and each time a charge-discharge operation is performed, the charge-discharge control unit 2 calculates the depth-of-discharge management value by successively adding and subtracting the charge-discharge amount converted from the charge-discharge current value detected by the charge-discharge current detector from the initial value, and holds the latest value. Then, the charge-discharge operation of the storage battery 100B is controlled so that the depth-of-discharge management value is maintained between 0% corresponding to the end of charging and 100% corresponding to the end of discharge. Known control methods can be appropriately applied to the control of the charging and discharging operations in the charge-discharge control unit 2, including the management of the depth of discharge.

[0045] In addition, the charge-discharge control unit 2 monitors the measured values of the temperature sensors 16 provided in the individual module batteries 12. When the measured value obtained from any of the temperature sensors 16 is within the operating temperature range but approaching the upper or lower limit of the range, or when the operating temperature range is not met, the charge-discharge control unit 2 stops or delays the charge-discharge according to the description content of the charge-discharge schedule.

[0046] Note that the measured values (actual measurement data) by the temperature sensors 16 and the depth-of-discharge management values are appropriately passed to the operation guidance device 11.

[0047] The heater control unit 3 controls the operation (ON / OFF switching) of the heater 15 based on the measured value of the temperature of each module battery 12 measured by the temperature sensor 16 and the set heat preservation temperature. Roughly speaking, the lower limit of the above-described operating temperature range is set as the heat preservation temperature, and the heater control unit 3 controls the operation of the heater 15 so that the temperature of each module battery 12 does not fall below the set heat preservation temperature. Thereby, even when the module battery 12 is in the standby state and during charging, the temperature of the module battery 12 is maintained within the operating temperature range.

[0048] The heat dissipation control unit 4 controls the operation (ON / OFF switching) of the fan provided in the fan 14 during the heat dissipation control period described in the heat dissipation schedule set based on the charge / discharge schedule.

[0049] The operation guidance device 11 can also be realized by a general-purpose or dedicated computer (control computer) equipped with a CPU, a memory, a storage, etc., similar to the storage battery control device 10. When a predetermined program stored in the storage is read and executed by the CPU, the operation guidance device 11 mainly includes an operation plan creation unit 6, a simulation processing unit 7, and a determination processing unit 8 as functional components.

[0050] The operation plan creation unit 6 is responsible for processing related to the creation and modification of an operation plan (charge / discharge plan) for the storage battery 100B. The operation plan creation unit 6 causes a display means (not shown) provided in the control computer to display a processing screen and a processing menu for creating an operation plan, and enables an operator of the operation guidance device 11 to perform operations such as formulating, inputting, and modifying an operation plan by operating an input means such as a mouse, a keyboard, or a touch panel (not shown) provided in the control computer. In the operation plan, a charge / discharge period during the planned target period and a charge / discharge output during the charge / discharge period are set.

[0051] In the present embodiment, one day (from 0:00 to 24:00) is divided into unit time divisions in 30-minute units, also referred to as "frames", and the charge / discharge output for each of 48 frames per day is set, for example, for two weeks, whereby an operation plan is created.

[0052] Furthermore, the creation of the operational plan shall be repeated daily, and the day following the creation date of each operational plan shall be the first day of the planning period for that operational plan. Therefore, if the creation of an operational plan with a planning period of two weeks is repeated, the only operational plan that is substantially newly created on a given creation date is the operational plan for the 14th day (the last day), which will be newly included in the planning period. For the remaining 13 days, the operational plan created on the previous day may be carried over as is, or it may be modified as appropriate according to the operating status of the battery 100B on that day, the trends in the electricity market, etc. Therefore, in this embodiment, the "creation" of the daily operational plan may be referred to as the "review" or "update" of the operational plan.

[0053] When creating (or revising) such operational plans, priority periods may be set within a portion of the planned period. Priority periods are designated as periods during which planned charging and discharging must be carried out reliably (with priority over other periods). When priority periods are set, the period preceding the priority period within the planned period is referred to as the preceding period, and the period after the end of the priority period is referred to as the succeeding period.

[0054] The simulation processing unit 7 is responsible for processing related to the simulation of the charge and discharge operation of the battery 100B in accordance with the operation plan. In this embodiment, the simulation of the charge and discharge operation of the battery 100B means the simulation of state indicator values ​​that indicate the state of the module batteries 12 constituting the battery 100B, such as battery temperature and remaining capacity (SOC), when the battery 100B is operating in accordance with the operation plan. The state indicator values ​​that are the subject of the simulation are also called the simulation target values.

[0055] The simulation processing unit 7 comprises a parameter setting unit 7a and a simulation execution unit 7b.

[0056] The parameter setting unit 7a is responsible for setting the parameters (simulation parameters) required for the simulation in the simulation execution unit 7b. In this embodiment, the simulation parameters to be set include the internal resistance r of the module battery 12, the heat dissipation amount loss, and the heat capacity C.

[0057] The simulation execution unit 7b uses the simulation parameters set by the parameter setting unit 7a to calculate the simulation target values ​​at predetermined time increments within each unit time segment.

[0058] When setting the initial value of the remaining capacity used in the simulation, the discharge depth management value held in the charge / discharge control unit 2 is referenced. When setting the initial value of the battery temperature, the temperature of the module battery 12 obtained by the battery control device 10 from the temperature sensor 16 is referenced. In addition, if an abnormality occurs in the state of the battery 100B, the simulation execution unit 7b acquires that information and uses it to correct the simulation parameters.

[0059] The simulation in the simulation execution unit 7b is performed daily in conjunction with the creation of a new operation plan in the operation plan creation unit 6.

[0060] If a priority period is set within a portion of the planned period, the simulation execution unit 7b will perform simulations for the priority period, the preceding period, and the succeeding period individually.

[0061] The determination processing unit 8 determines whether or not to adopt the operational plan that was the subject of the simulation, based on the results of the simulation performed by the simulation execution unit 7b. If the determination processing unit 8 determines that the operational plan is adoptable, the operational plan is finalized, and the finalized operational plan is sent to the battery control device 10 as a charge / discharge schedule.

[0062] In general terms, the determination processing unit 8 determines whether operation is possible for each unit time segment included in the operation plan, based on whether the SOC and battery temperature of each module battery 12 obtained by simulation are within a predetermined allowable range. Based on the result of this determination, it then determines whether the operation plan that was the subject of the simulation is to be adopted. The upper and lower limits of the allowable range (operable range) of the simulation target values ​​are predetermined and stored in the operation guidance device 11.

[0063] The determination process in the determination processing unit 8 is also performed daily in conjunction with the creation of the operation plan in the operation plan creation unit 6 and the simulation in the simulation execution unit 7b.

[0064] If a priority period is set for part of the planned period, the determination processing unit 8 performs processing according to the results of the simulations applied to the priority period, the preceding period, and the succeeding period, respectively.

[0065] In the explanation so far, it has been assumed that the operation plan creation unit 6, the simulation processing unit 7, and the determination processing unit 8 are realized as functional components of a computer that functions as an operation guidance device 11. However, this configuration can also be understood as a configuration in which a simulation device realized by a computer having the function of the simulation processing unit 7 combines the functions of the operation plan creation unit 6 and the determination processing unit 8. From another perspective, the operation guidance device 11 according to this embodiment can also be said to be a simulation device that combines the functions of the simulation processing unit 7 and the determination processing unit 8.

[0066] Alternatively, a simulation device implemented by a computer having the functions of a simulation processing unit 7, an operation plan creation device implemented by a computer having the functions of an operation plan creation unit 6, and an adoption / rejection determination device implemented by a computer having the functions of a determination processing unit 8 may be configured separately.

[0067] <Simulation Overview> Next, we will explain the overview of the simulation of the charging and discharging operation of the battery 100B in accordance with the operation plan, which is performed in the simulation execution unit 7b.

[0068] Figure 3 shows the basic flow of the simulation. The simulation is performed on all "frames," or unit time divisions, of the target period, but Figure 3 illustrates a simulation that targets a single frame.

[0069] First, the following initial values ​​are set (step S1).

[0070] Operating output time: T; Time step: Δt; Operating output: Pn; Remaining capacity: SOC; Battery temperature: Temp;

[0071] More specifically, the operational output time T is 30 minutes, which is the length of the time slot. The time step Δt is set to approximately 10 seconds to 10 minutes. The operational output Pn is set to the charge / discharge power value of the time slot as described in the operational plan.

[0072] The initial value of the remaining capacity (SOC) is set based on the discharge depth control value at the start of the operational plan that is the subject of the simulation. In this embodiment, the remaining capacity (SOC) = 100% - discharge depth (control value).

[0073] The initial value of the battery temperature Temp is set to a temperature within the operating temperature range, based on the battery temperature at the start of the operation plan being simulated.

[0074] In principle, the SOC and battery temperature of each individual module battery 12 constituting the storage battery 100B may differ. However, since these module batteries 12 are connected in series to form a collective battery 13, in the simulation, under the assumption that the module batteries 12 operate similarly, it may be assumed that the remaining capacity SOC and battery temperature Temp of each module battery 12 are the same, without distinguishing between them, and each value may be represented by a single simulation value. Alternatively, if differences in battery temperature and SOC during charging and discharging may occur among the module batteries 12 constituting the collective battery 13 due to manufacturing variations in the module batteries 12 or the failure status of the cells (single cells) within the module batteries 12, the simulation values ​​obtained from the module battery 12 that tends to have the highest battery temperature, the module battery 12 that tends to have the highest SOC, or the module battery 12 that tends to have the lowest SOC may be used to represent the values.

[0075] Next, the number of loops N executed in the latter half of the simulation is calculated using the formula N = T / Δt (step S2).

[0076] Next, with n set to 1 (step S3), the battery current In is determined from the operational output Pn (step S4).

[0077] Furthermore, using the battery current In value calculated in step S4, the time step Δt set as the initial value in step S1, and the most recent remaining capacity SOC value, the remaining capacity SOC at the point when time has advanced by Δt is calculated using the formula SOC = SOC - In × Δt (step S5).

[0078] Furthermore, using the value of the battery current In calculated in step S4, the time step Δt set as the initial value in step S1, the value of the most recent battery temperature Temp, the internal resistance r of the module battery 12, the heat dissipation loss, and the heat capacity C, the battery temperature Temp at the point when time has advanced by Δt is calculated using the formula Temp = Temp + (In × In × r) × Δt / C (step S6).

[0079] Here, the internal resistance r, heat dissipation loss, and heat capacity C of the module battery 12 are simulation parameters (constants) that are predetermined in the parameter setting unit 7a and stored in a memory unit (not shown) of the operation guidance device 11.

[0080] The order of steps S5 and S6 may be reversed, and they may be performed in parallel.

[0081] Next, n = n + 1 (step S7), and if n > N for the new n is not true (NO in step S8), then steps S5 to S7 are repeated at time intervals Δt.

[0082] On the other hand, if n > N (YES in step S8), the latest calculated values ​​of the remaining capacity SOC and the battery temperature Temp are output as simulation results of the remaining capacity and battery temperature of the storage battery 100B at the end of the frame (step S9).

[0083] For all module batteries 12, if the remaining capacity and battery temperature output in step S9 are both within the predetermined allowable range for all timeframes included in the planned period, the determination processing unit 8 determines that the operation plan subject to simulation is feasible ("operable"). Conversely, if at least one of the remaining capacity and battery temperature output in step S9 for any timeframe of any module battery 12 deviates from the predetermined allowable range, the determination processing unit 8 determines that the operation plan subject to simulation is not feasible ("not operable").

[0084] The operation plan, which is determined to be "operational" by the determination processing unit 8, is sent to the battery control device 10 as a charge / discharge schedule and is executed in the battery 100B on the following day or later.

[0085] On the other hand, if the operation plan is determined to be "unoperable," a display prompting the user to recreate or revise the operation plan will be shown on a display unit (not shown) of the operation guidance device 11.

[0086] <Creating and Simulating Daily Operational Plans> (When no priority period is set) Figure 4 is a diagram that specifically explains the creation of daily operational plans and the simulations that accompany them. As an example, Figure 4 assumes that an operational plan with a target period of two weeks, created on August 31st and finalized after simulation, is reviewed each day from September 1st onwards.

[0087] More specifically, on August 31, the operational plan is created with the period from September 1 to September 14 as the target period Term 0, and the finalized operational plan is sent to the battery control device 10 as a charge / discharge schedule with a start time of 0:00 on September 1.

[0088] The operation plan will be implemented from 0:00 on September 1st, but on the other hand, when the creation start timing Tm1, which is set to, for example, 12:00 on that day, arrives, the operation plan creation unit 6 will start creating an operation plan for the period from September 2nd to September 15th, which will be the planned period Term1.

[0089] However, since the operational plan for September 2nd to September 14th has already been prepared the day before, the actual work involved will be a review of its contents, taking into account the operational performance of battery 100B and the conditions of the electricity market during the period Ta from 0:00 on the day until the start of preparation Tm1. If there are no changes to the operational plan for September 2nd to September 14th, the only operational plan that will be effectively newly prepared on September 1st will be the one for September 15th.

[0090] Regardless of whether or not there are any changes to the operational plan from September 2nd to September 14th, once an operational plan for the planned period Term1 is created after the creation start timing Tm1, the simulation execution unit 7b then executes a simulation targeting that operational plan.

[0091] In this simulation, the remaining capacity and measured battery temperature data, reflecting the operational performance of the battery 100B during period Ta, are used as initial values. Furthermore, considering continuity, the operational plan for period Tb between period Ta and planned period Term 1, which was created the previous day, is also included in the simulation.

[0092] In other words, the simulation on September 1st will effectively run with the simulation period Sim1, which includes September 1st to September 15th, including that day.

[0093] The determination processing unit 8 determines whether or not to adopt the operational plan for the planned period Term 1 based on the simulation results for the simulation target period Sim 1. If it is determined that the plan is adoptable, the operational plan is finalized and sent to the battery control device 10 as the charge / discharge schedule for the planned period Term 1.

[0094] The process from September 2nd onwards is similar, with the creation of operational plans for planned periods Term 2, Term 3, etc., shifted by one day from planned period Term 1, being carried out daily. Accordingly, the simulation period is also shifted. For example, the simulation on September 2nd uses actual measured data of the battery 100B's operational output, remaining capacity, and battery temperature, reflecting the battery's operational performance during period Ta up to the start of creation timing Tm2 on that day, as initial values. The simulation is then run for the period Tb between period Ta and planned period Term 2, and for planned period Term 2, with the period from September 2nd to September 16th, including that day, as the simulation period Sim2.

[0095] In other words, if no priority period is set, the simulation execution unit 7b runs a simulation on a daily basis, covering the simulation period including the planned period. Based on the results of this simulation, the decision processing unit 8 determines whether the operation plan is feasible or not.

[0096] In the example shown in Figure 4, the downtime is set to be a few hours (for example, 6 hours) leading up to 24:00 on August 31st.

[0097] The rest period is a period during which neither charging nor discharging occurs, in order to stabilize the temperature of the 100B battery (battery temperature). By implementing a rest period, the effects of temperature rise due to charging and discharging, and the effects of changes in cooling amount due to turning the cooling fan on and off are minimized, thereby stabilizing the battery temperature. The time when the battery temperature stabilizes after the start of the rest period is called the stabilization time.

[0098] For example, when using a 100B battery to charge with electricity generated by solar power during the day and discharge it at night, the operation plan often includes a downtime. However, when using a 100B battery to bid in the supply and demand adjustment market, short-term charging and discharging cycles are repeated continuously, so the operation plan often does not include a downtime.

[0099] When the operational plan covers the period following the suspension period, a more accurate simulation can be performed compared to when the operational plan does not cover that period.

[0100] (When a priority period is set) [Securing a downtime and continuous simulation: Conventional processing method] Next, we will explain the method of creating an operational plan and conducting simulations when a priority period is set in the middle of the planned period. First, for comparison, we will explain the conventional method.

[0101] Figure 5 illustrates the conventional processing method when a priority period is set. As an example, Figure 5 assumes that, similar to Figure 4, an operational plan with a two-week planning period, created on August 31 and finalized after simulation, is reviewed on September 1, the following day, and the entire day of September 7 is set as the priority period PR. In addition, in the example shown in Figure 5, a pause period IA1 and a pause period IA2 are set immediately before and after the priority period PR, respectively.

[0102] On the other hand, Figure 6 shows an example of the state change of the battery 100B during the priority period and the preceding preceding period when the idle period IA1 is not provided. Figure 6(a) shows the change in power, Figure 6(b) shows the change in SOC (state of charge), and Figure 6(c) shows the change in temperature. In Figure 6(a), the discharge side is considered positive and the charging side is considered negative.

[0103] If no rest period is provided, the state of the battery 100B at the end of the preceding period becomes the initial state of the battery 100B at the start of the priority period. Therefore, as shown in Figure 6(a), if discharge is scheduled between the start time t0 of the priority period and a certain time t1, as shown in Figure 6(b), the SOC of the battery 100B will continue to decrease from the value SOC(t0) at time t0. Also, as shown in Figure 6(c), the temperature of the battery 100B will continue to rise from the value T(t0) at time t0. Therefore, depending on the discharge conditions, the magnitude of SOC(t0), and the height of T(t0), there is a risk that the SOC may become 0 at time ta before time t1, or that the battery temperature may reach the upper limit temperature Tu of the allowable range at time tb before time t1.

[0104] If an operational plan is adopted in which charging and discharging operations in the priority period are performed immediately following charging and discharging operations in the preceding period, even if simulations are conducted and the operational plan is finalized to prevent the above-mentioned problems from occurring, depending on the actual operating conditions of the battery 100B, the initial state of the battery 100B at the start of the priority period may be more severe than assumed in the simulation, which could result in the above-mentioned problems occurring.

[0105] In light of this, conventionally, when setting a priority period PR, it was practically essential to set a pause period IA1 immediately before the priority period PR to stabilize the state of the battery 100B, as shown in Figure 5, in order to ensure that the charging and discharging scheduled for the priority period PR were carried out reliably. Furthermore, in order to secure SOC during the priority period PR, it was sometimes necessary to revise the operational plan prior to the pause period IA1.

[0106] In addition, in order to minimize revisions to the operational plan after the priority period PR and to return to the operational plan planned for the period after the priority period PR as soon as possible, it was sometimes necessary to set up a shutdown period IA2 immediately after the priority period PR. In some cases, instead of or prior to the shutdown period IA2, an SOC adjustment period was set up to perform charging and discharging to adjust the SOC.

[0107] Furthermore, in the conventional approach, simulations to determine the feasibility of implementing an operational plan were performed as continuous simulations covering the entire planning period (for example, if September 1st was the date, the simulation period Sim1 would be the target), similar to cases where no priority period was set. Therefore, if a simulation targeting an operational plan that included a priority period PR within the planning period determined that the operational plan was unacceptable, it was necessary to redo the simulation covering the entire planning period, regardless of whether the cause lay within the priority period PR or outside of it.

[0108] [Split Simulation] In this embodiment, taking into consideration the circumstances of the conventional embodiment, the procedures and content for creating and simulating the operational plan when a priority period is set in the middle of the planned period have been devised to ensure the certainty of implementing the operational plan in the priority period while enabling efficient simulation. In general terms, in this embodiment, the feasibility of implementing the operational plan including the priority period is determined based on the results of individual simulations (split simulations) targeting the priority period, the preceding period, and the succeeding period, respectively. This will be explained below.

[0109] Figure 7 shows the processing procedure in this embodiment when a priority period is set in the middle of the planned period.

[0110] First, the operator of the operation guidance device 11 formulates and inputs a desired operation plan (initial plan), including the setting of a priority period (the period to be set and the desired charge / discharge pattern) (step S101). Except for the period to be set as the priority period and the operation plan for the last day newly included in the set period, the operation plan created on the previous day may be carried over.

[0111] Figure 8 is a diagram illustrating the processing method adopted in this embodiment when a priority period is set. In Figure 8, similar to the example shown in Figure 5, it is assumed that on August 31, the operational plan is created with September 1st to September 14th as the planned period Term0, and after simulation, the finalized operational plan is reviewed on September 1st, the following day, and the entire day of September 7th is set as the priority period PR. In this case, the planned period Term1 on September 1st will be divided into the priority period PR on September 7th, the preceding period from September 2nd to September 6th, and the succeeding period from September 8th to September 15th. However, unlike the example shown in Figure 5, the idle periods IA1 and IA2 are not set.

[0112] Once the operational plan, including the setting of priority periods, is entered, a process is then performed to finalize the operational plan for the priority periods.

[0113] Specifically, first, the simulation execution unit 7b creates multiple battery conditions (initial conditions) for the start of the priority period by different combinations of SOC (State of Condition), which is an indicator of the state of the storage battery 100B, and the set value (initial value) of the battery temperature. Then, the simulation execution unit 7b performs multiple simulations applying each battery condition to the charge and discharge patterns that are desired to be executed during the priority period (step S102). Alternatively, the operator of the operation guidance device 11 may input the battery conditions as appropriate. In the case shown in Figure 8, a simulation will be performed with September 7th as the simulation target period Sim1a.

[0114] Once multiple simulations are completed, the determination processing unit 8 determines whether any of the simulation results indicate that operation is possible during the priority period (step S103). More specifically, it determines whether there are any battery conditions that yield simulation results in which the SOC and battery temperature are kept within acceptable limits until the end of the priority period.

[0115] If no such simulation results are obtained (NO in step S103), the process of resetting the priority period itself or resetting the battery conditions at the start of the priority period (step S101) and performing a simulation (step S102) is repeated until a suitable simulation result is obtained.

[0116] On the other hand, if such a simulation result exists (YES in step S103), the determination processing unit 8 identifies the range of battery conditions (initial conditions) at the start of the priority period that yielded the corresponding simulation result and the range of battery conditions at the end of the priority period in the corresponding simulation result (step S104), and stores them in a storage unit (not shown) of the operation guidance device 11. The former corresponds to the range that the battery conditions should satisfy at the start of the priority period, i.e., at the end of the preceding period, and the latter corresponds to the range that the battery conditions can take at the end of the priority period, i.e., at the start of the subsequent period.

[0117] Figure 9 shows an example of the state change of the storage battery 100B when simulation results are obtained that the SOC and battery temperature are kept within acceptable limits, illustrating the range that the battery conditions should meet at the start of the priority period. Figure 9(a) shows the change in power, Figure 9(b) shows the change in SOC (remaining capacity), and Figure 9(c) shows the change in temperature. In Figure 9(a), the discharge side is considered positive and the charge side is considered negative. The settings for the priority period are assumed to be the same as in the example shown in Figure 6.

[0118] For example, as shown in Figure 9(a), if a priority period is set from time t0 onwards, and continuous discharge is set between time t0 and time t1, the State of Charge (SOC) of the battery 100B will be at its maximum at time t0 and will decrease thereafter as the discharge continues. Therefore, as shown in Figure 9(b), if we let C1 be the minimum value of the SOC set under the battery conditions (initial conditions) that resulted in the simulation result that operation was deemed possible during the priority period, then as long as the SOC at the start of the priority period is C1 or greater, it is considered that the SOC will not fall to 0% during the charge / discharge operation set for the priority period.

[0119] Based on this approach, the determination processing unit 8 identifies the range of the battery conditions (initial conditions) in the SOC that yielded simulation results deemed operational during the priority period, from the minimum value to the maximum value, as the starting capacity condition, which is one of the battery condition ranges that should be satisfied at the start of the priority period.

[0120] Furthermore, regarding battery temperature, as shown in Figure 9(a), when the priority period and discharge settings are configured, the temperature is at its lowest at time t0 and rises thereafter as the discharge continues. Therefore, as shown in Figure 9(c), if T1 is the highest value of the battery temperature set under the battery conditions (initial conditions) that resulted in the simulation result that operation was deemed possible during the priority period, then if the battery temperature at the start of the priority period is T1 or less, it is considered that the battery will not reach the upper limit temperature Tu of the acceptable range during the charge and discharge operation set for the priority period.

[0121] Based on this approach, the determination processing unit 8 identifies the range of the battery temperature between the minimum and maximum values ​​of the battery conditions (initial conditions) that yielded simulation results deemed operational during the priority period as the starting temperature condition, which is one of the battery condition ranges that should be met at the start of the priority period.

[0122] On the other hand, the battery condition range at the end of the priority period is determined as the termination capacity condition and termination temperature condition, respectively, which are the range between the minimum and maximum values ​​of the SOC at the end of the simulation results that determined the battery was operational during the priority period.

[0123] As described above, once the battery conditions at the start and end of the priority period have been identified, the process to finalize the operational plan for the preceding period is then carried out.

[0124] Specifically, first, the simulation execution unit 7b performs a simulation of the operational plan for the preceding period (step S105). This simulation is performed in the same way as when no priority period is set, except that the period covered is only the preceding period. Changes may be made prior to the simulation, but even though a priority period is set, it is not essential to set a pause period in advance in this embodiment.

[0125] In the case shown in Figure 8, the simulation will be run with the period Sim1b set as the simulation target period, from September 1st, the day the operational plan is created, to September 6th, immediately preceding the priority period. In this case, the treatment of periods Ta and Tb is the same as when no priority period is set.

[0126] The operational plan for the preceding period is the same as the one that was simulated the previous day and deemed operational, unless changed. However, the operating status of battery 100B during period Ta, which is the initial value, may differ from the previous day. Therefore, whether or not changes are made, a new simulation is performed to determine whether or not operation is feasible.

[0127] Once the results of the simulation for the preceding period are obtained, the determination processing unit 8 determines whether or not to implement the operational plan for the preceding period based on these results (step S106).

[0128] If the SOC and battery temperature are within the acceptable range during the preceding period, the determination processing unit 8 determines that the operation plan for the preceding period itself is feasible (YES in step S106). However, in order to determine whether it is possible to proceed with the operation of the priority period following that operation, it determines whether the SOC and battery temperature at the end of the preceding period meet the previously identified battery condition range at the start of the priority period (step S107).

[0129] For the priority period, for the reasons stated above, the set operation plan can be executed if the initial battery condition range (initial capacity condition and initial temperature condition) is met. The SOC and battery temperature at the end of the preceding period are none other than the SOC and battery temperature at the start of the priority period. Therefore, if they meet the initial battery condition range (YES in step S107), it can be determined that the operation plan for the preceding period, including the subsequent transition to the operation plan for the priority period, can be executed.

[0130] Furthermore, providing a rest period is not essential for the SOC and battery temperature at the end of the preceding period to meet the battery condition range. Therefore, according to this embodiment, it is possible to utilize the storage battery 100B with higher utilization efficiency compared to the conventional embodiment in which providing a rest period was substantially essential.

[0131] On the other hand, if it is determined that the operational plan for the preceding period is not feasible (NO in step S106), or if it is determined that the SOC and battery temperature at the end of the preceding period do not meet the battery condition range at the start of the priority period (NO in step S107), the operational plan for the preceding period is revised (step S108), and the simulation is performed again (step S105).

[0132] In the case shown in Figure 8, the simulation for the simulation target period Sim1b would need to be redone. However, this would require less time compared to redoing the simulation, which would include the entire planning target period Term1, as in the conventional approach.

[0133] Figure 10 shows an example where the battery condition range at the start of the priority period is satisfied by modifying the operational plan for the preceding period. Figure 10(a) shows the change in power, Figure 10(b) shows the change in SOC (state of charge), and Figure 10(c) shows the change in temperature. In Figure 10(a), the discharge side is considered positive and the charge side is considered negative. The settings for the priority period are assumed to be the same as in the example shown in Figure 6.

[0134] In Figure 10, as shown in Figure 10(a), a priority period is set from time t0 onwards, and the system is set to discharge continuously between time t0 and time t1. As shown by the arrows in the figure, the operation plan for the preceding period is modified to cancel the discharge immediately before the priority period. As a result, as shown in Figure 10(b), the SOC value SOC(t0) at time t0 becomes greater than or equal to the minimum value C1 in the starting capacity condition, and as shown in Figure 10(c), the battery temperature value T(t0) at time t0 becomes less than or equal to the maximum value T1 in the starting temperature condition.

[0135] In this embodiment, it is not mandatory to set the end of the preceding period as a downtime, but it is permissible to set a minimum downtime when modifying the operation plan for the preceding period so that the SOC and battery temperature at the end of the preceding period meet the battery condition range at the start of the priority period. The set time in such cases may be adjusted as appropriate according to the battery condition range at the start of the priority period.

[0136] If it is determined that a transition from the operational plan for the preceding period to the operational plan for the priority period is possible (YES in step S107), then the operational plan for the preceding period is finalized.

[0137] Once the operational plan for the preceding period is finalized, the process then proceeds to finalize the operational plan for the subsequent period.

[0138] Specifically, first, the simulation execution unit 7b performs a simulation of the operation plan for the subsequent period (step S109), and the determination processing unit 8 determines whether or not the operation plan for the subsequent period can be implemented based on the results of the simulation (step S110). In the case shown in Figure 8, the simulation will be performed with the simulation target period Sim1c set from September 8, immediately following the priority period, to September 15, the last day of the planned period Term 1.

[0139] The operational plan for the subsequent period will be the same as the one that was simulated the previous day and deemed operational, unless changed, except for the final day that is newly added to the target period. While changes may be made prior to the simulation, even though a priority period is provided, this embodiment does not immediately include a suspension period.

[0140] However, simulations covering subsequent periods are performed using initial values ​​determined from the termination capacity conditions and termination temperature conditions, which are identified as the battery condition range at the end of the priority period. Specifically, two types of simulations are performed: a first simulation using the minimum value of SOC under the termination capacity conditions and the maximum value of the battery temperature under the termination temperature conditions as the first initial values, and a second simulation using the maximum value of SOC under the termination capacity conditions and the maximum value of the battery temperature under the termination temperature conditions as the second initial values.

[0141] Then, the determination processing unit 8 determines that operation using the first initial value is possible based on the results of the first simulation, and also determines that operation using the second initial value is possible based on the results of the second simulation, and if so, it determines that operation using the operation plan for the subsequent period is possible (YES in step S110).

[0142] The combination of SOC and battery temperature values ​​in the first and second initial values ​​corresponds to the boundary conditions within the range of battery conditions that the battery conditions can take at the end of the priority period, i.e., at the start of the subsequent period. In other words, it is the combination of battery conditions that is most severe when executing the operation plan for the subsequent period. Specifically, the first initial value corresponds to a battery condition where further discharge becomes difficult, and the second initial value corresponds to a battery condition where further charging or discharging becomes difficult.

[0143] Since the actual SOC and battery temperature at the end of the priority period should be between the first and second initial values, if the operation plan for the subsequent period using the first and second initial values ​​is feasible, then it is naturally considered possible to operate (charge and discharge) using the values ​​in between as initial values.

[0144] If it is determined that the operation plan for the subsequent period is not feasible because at least one of the operations using the first initial value and the operation using the second initial value is deemed impossible (NO in step S110), the operation plan for the subsequent period is revised (step S111), and the simulation is performed again (step S109).

[0145] In the case shown in Figure 8, the simulation for the simulation target period Sim1c would need to be redone. However, this would require less time compared to redoing the simulation, which would include the entire planning target period Term1, as in the conventional method.

[0146] In this embodiment, it is not mandatory to set the beginning of the subsequent period as a downtime period. However, it is permissible to set a minimum downtime or SOC adjustment period when modifying the operation plan for the subsequent period, in order to ensure that the SOC and battery temperature at the start of the subsequent period meet the battery condition range at the end of the priority period. In such cases, the set time may be appropriately adjusted according to the battery condition range at the end of the priority period.

[0147] If the determination processing unit 8 determines that the operation plan for the subsequent period can be implemented, the operation plan, including the priority period, will be finalized for the period for which the operation plan is set. In the case shown in Figure 8, the creation of the operation plan for September 1st will be completed.

[0148] If a new operational plan is to be created (or revised) on the following day or later, the procedure shown in Figure 7 is basically repeated. However, setting a new priority period (step S101) is not required.

[0149] If no new priority period is set, the priority period set up by the previous day will remain the priority period for the planned period, and the periods before and after that priority period will be treated as the preceding and succeeding periods, respectively.

[0150] In the case shown in Figure 8, an operational plan was created on September 1st with September 7th as the priority period, but no new priority period was set on the following day, September 2nd. Therefore, within the planned period Term 2 on September 2nd, which is from September 3rd to September 16th, September 3rd to September 6th is designated as the preceding period, and September 8th to September 16th is designated as the succeeding period. Then, simulations are performed for the priority period with September 7th as the simulation target period Sim2a, for the preceding period with September 2nd to September 6th as the simulation target period Sim2b, and for the priority period with September 8th to September 16th as the simulation target period Sim2c. Appropriate processing is then carried out based on the results of each simulation.

[0151] Furthermore, if a new priority period is established, that priority period will be treated as a priority period for the planned period, just like the priority period established up to the previous day. If such establishment results in a period being sandwiched between preceding and succeeding priority periods, that period must simultaneously satisfy both the battery condition range requirements at the start of the later priority period and the battery condition range requirements at the end of the earlier priority period.

[0152] As explained above, in this embodiment, when a priority period is set in the battery operation plan to ensure that charging and discharging are carried out as planned, the battery conditions at the start and end of the priority period that enable the reliable implementation of the operation plan during the priority period are first identified based on the results of a simulation targeting only that priority period. Then, the feasibility of implementing the operation plan in the preceding period and the subsequent period following the priority period is determined based on the results of simulations targeting each respective period and the battery conditions at the start and end of the priority period. If it is determined that the operation plan for each period is not feasible, it is sufficient to revise the operation plan and redo the simulation targeting only that period. This reduces the time required for processing the operation plan revision compared to the conventional method of redoing the simulation for the entire planned period. Therefore, it is possible to create an operation plan including the priority period more efficiently than the conventional method of determining the feasibility of the operation plan based on the results of a simulation for the entire planned period.

[0153] Furthermore, while conventional methods essentially required a pause period before and after the priority period in order to stabilize the battery temperature, in this embodiment, the pause period can be omitted depending on the battery condition range at the start and end of the priority period. Therefore, it is possible to utilize the storage battery with higher utilization efficiency than conventional methods.

Claims

1. A method for creating an operation plan for a storage battery that includes a priority period as part of the planned period, comprising: a planning step of setting a schedule for charging and discharging the storage battery for each unit time during a predetermined planned period, setting a part of the planned period as a priority period, and creating an operation plan for a storage battery in which the planned period consists of the priority period, a preceding period preceding the priority period, and a succeeding period following the priority period; and a priority period processing step of performing multiple first simulations, each with a different value of the battery condition, which is an indicator of the state of the storage battery, at the start of the priority period, for the priority period only of the operation plan, determining for each of the multiple first simulations whether the operation plan can be operated during the priority period, and if there is no operation plan that is determined to be operable during the priority period, modifying the operation plan and repeating the multiple first simulations; A method for creating an operation plan for a storage battery, comprising: a battery condition identification step, which, based on the simulation results obtained in the priority period processing step, that the operation plan can be operated during the priority period, identifies a first range that the battery conditions should satisfy at the end of the preceding period and a second range that the battery conditions should satisfy at the start of the subsequent period; a preceding period processing step, which performs a second simulation targeting only the preceding period of the operation plan, and if the simulation results indicate that the operation plan cannot be operated during the preceding period, or if the first range is not satisfied, modifies the operation plan for the preceding period and repeats the second simulation; and a subsequent period processing step, which uses each of the two boundary conditions in the second range as the initial value of the battery conditions, performs two third simulations targeting only the subsequent period, and if at least one of the two third simulations indicates that the operation plan cannot be operated during the subsequent period, modifies the operation plan for the subsequent period and repeats the third simulation.

2. A method for creating an operation plan for a storage battery according to claim 1, characterized in that the battery conditions are the remaining capacity and temperature of the storage battery, in the battery condition identification step, a first range and a second range are identified for the remaining capacity and the temperature, in the preceding period processing step, if the first range of either the remaining capacity or the temperature is not met, the operation plan for the preceding period is modified, and in the succeeding period processing step, two types of boundary conditions are determined based on the combination of the second ranges of the remaining capacity and the temperature.

3. A method for creating an operation plan for a storage battery according to claim 2, characterized in that, in the battery condition identification step, among the battery conditions at the start of the priority period used in the plurality of first simulations, the range of the remaining capacity between the minimum and maximum values ​​and the range of the temperature between the minimum and maximum values ​​for the battery conditions that yielded a simulation result indicating that the operation plan can be implemented during the priority period are identified as the first range for the remaining capacity and the temperature, respectively.

4. A method for creating an operation plan for a storage battery according to claim 2 or claim 3, characterized in that, in the battery condition identification step, the range of the remaining capacity at the end of the priority period, which is between the minimum and maximum values ​​of the remaining capacity and the range of the temperature at the end of the priority period, is identified as the second range for the remaining capacity and the temperature, respectively, for the simulation in which the result obtained that the operation plan can be operated during the priority period among the plurality of first simulations.

5. A device for creating an operation plan for a storage battery, comprising: an operation plan creation unit that creates and modifies an operation plan for a storage battery, which sets a schedule for charging and discharging the storage battery at unit time intervals during a predetermined planning period; a simulation execution unit that can execute a simulation targeting the operation plan for the storage battery; and a determination processing unit that determines whether or not the operation plan can be implemented based on the results of the simulation, wherein in the operation plan, a priority period is set for a part of the planning period, and the planning period consists of the priority period, a preceding period preceding the priority period, and a subsequent period following the priority period, the simulation execution unit is capable of executing: a first simulation targeting only the priority period; a second simulation targeting only the preceding period; and a third simulation targeting only the subsequent period, respectively, and the determination processing unit is capable of determining whether or not the operation plan can be implemented during the priority period, the preceding period, and the subsequent period, based on the results of the first simulation, the second simulation, and the third simulation, respectively. The simulation execution unit performs multiple first simulations with different values ​​for the battery conditions, which are an indicator of the state of the storage battery, at the start of the priority period; the determination processing unit determines for each of the multiple first simulations whether the operation plan can be operated during the priority period; if there is no operation plan that is determined to be operable during the priority period, the operation plan creation unit modifies the operation plan, and then the simulation execution unit repeats the first simulation; if a simulation result is obtained in one of the multiple first simulations indicating that the operation plan can be operated during the priority period, the simulation execution unit identifies a first range that the battery conditions should satisfy at the end of the preceding period and a second range that they should satisfy at the start of the succeeding period, based on the simulation result; and once the first range and the second range have been identified, the simulation execution unit executes the second simulation.The determination processing unit determines, based on the results of the second simulation, whether the operation plan can be implemented during the preceding period and whether the battery conditions satisfy the first range at the end of the preceding period. If the simulation result indicates that the operation plan cannot be implemented during the preceding period, or if the result indicates that the first range is not satisfied, the operation plan creation unit modifies the operation plan for the preceding period and then causes the simulation execution unit to repeat the second simulation. The simulation execution unit performs two types of third simulations, using each of the two types of boundary conditions in the second range as the initial value of the battery conditions. The determination processing unit determines, based on the results of the two types of third simulations, whether the operation plan can be implemented during the subsequent period. If the simulation result indicates that the operation plan cannot be implemented during the subsequent period in at least one of the two types of third simulations, the operation plan creation unit modifies the operation plan for the subsequent period and then causes the simulation execution unit to repeat the third simulation. This is the operation plan creation support device.

6. An operation plan creation support device according to claim 5, wherein the battery conditions are the remaining capacity and temperature of the storage battery, the determination processing unit specifies a first range and a second range for each of the remaining capacity and the temperature, causes the operation plan creation unit to modify the operation plan for the preceding period if the first range for either the remaining capacity or the temperature is not met, and determines the two types of boundary conditions based on the combination of the second ranges for each of the remaining capacity and the temperature.

7. An operation plan creation support device according to claim 6, characterized in that the determination processing unit identifies, among the battery conditions at the start of the priority period used in the plurality of first simulations, the range of the remaining capacity between the minimum and maximum values ​​and the range of the temperature between the minimum and maximum values, respectively, as the first range for the remaining capacity and the temperature, in the battery conditions that yielded a simulation result indicating that the operation plan can be implemented during the priority period.

8. An operation plan creation support device according to claim 6 or claim 7, characterized in that the determination processing unit identifies the range of the remaining capacity at the end of the priority period, which is between the minimum and maximum values ​​of the remaining capacity and the range of the temperature at the end of the priority period, as the second range for the remaining capacity and the temperature, respectively, for the simulation in which the result obtained that the operation plan can be implemented during the priority period among the plurality of first simulations.

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