Power supply system

Abstract

To provide a power supply system that minimizes capital investment.SOLUTION: A power supply system includes a solar power generation device 13 that generates power when irradiated with sunlight, a fuel cell 14 that generates power when supplied with fuel, a secondary battery 15 that can be charged and discharged, and a control unit 16 that controls the solar power generation device 13, the fuel cell 14, and the secondary battery 15. The control unit 16 obtains a power demand forecast of the power that is to be required from the power demand 11 and a solar power generation forecast of the power that is to be generated by the solar power generation device 13, and formulates an operation plan for operating the fuel cell 14, the solar power generation device 13, and the secondary battery 15 in response to the power demand 11 on the basis of the power demand forecast and the solar power generation forecast, and controls the operation of the fuel cell 14 to follow the power demand load of the power demand 11 based on the operation plan.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a power supply system. [Background technology]

[0002] Conventionally, a power supply system having a fuel cell to which load following control is applied and a secondary battery for supplementing the load following capability of the fuel cell has been proposed, for example, in Patent Document 1. In this power supply system, when the power consumption of the load increases, a first discharge control is performed to discharge the secondary battery so as to supplement the shortfall in the output power of the fuel cell.

[0003] In addition, in the power supply system, when the power consumption of the load increases and exceeds the rated output power of the fuel cell, a first discharge control is performed, and then a second discharge control is performed to further discharge at least a portion of the stored electricity in the secondary battery. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-074757 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned conventional technology, the shortage of the fuel cell's output power is compensated for by the amount of electricity stored in the secondary battery, so there is a possibility that the amount of electricity stored in the secondary battery will quickly run out.

[0006] One solution is to increase the storage capacity of secondary batteries in advance. In other words, prepare a large number of secondary batteries in advance. However, the capital investment costs for power supply systems that supply power to loads are high. Furthermore, without a well-planned operation plan, energy consumption and energy costs may increase further. In other words, introducing secondary batteries requires a large capital investment, and there is a possibility that the cost and operation of the power supply system may not be viable.

[0007] In view of the above, an object of the present invention is to provide a power supply system that takes into consideration minimizing capital investment. [Means for solving the problem]

[0008] In order to achieve the above object, in the invention described in claim 1, the power supply system includes a solar power generation device (13) that generates electricity when exposed to sunlight, a fuel cell (14) that generates electricity when supplied with fuel, a secondary battery (15) that can be charged and discharged, and a control unit (16) that controls the solar power generation device, the fuel cell, and the secondary battery.

[0009] The control unit obtains a power demand forecast of the power that will be required from the power demand (11) and a solar power generation forecast of the power that will be generated by the solar power generation device, and creates an operation plan for operating the fuel cell, the solar power generation device, and the secondary battery in response to the power demand based on the power demand forecast and the solar power generation forecast, and controls the operation of the fuel cell to follow the power demand load of the power demand based on the operation plan.

[0010] This allows the secondary battery to be charged with the discharge amount required to compensate for the load-following delay of the fuel cell using the surplus solar power generation from the solar power generation device and the minimum surplus power generation from the fuel cell. This eliminates the need for excessive secondary battery equipment, allowing for reduced capital investment for secondary batteries. Therefore, it is possible to provide a power supply system that takes into consideration minimizing capital investment.

[0011] The symbols in parentheses for each means described in this section and in the claims indicate the correspondence with the specific means described in the embodiments described later. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram showing the overall configuration of a power supply system according to a first embodiment. [Figure 2]10 is a flowchart showing the contents of an operation plan for a secondary battery. [Figure 3] 10 is a flowchart showing the contents of the charge / discharge control of the secondary battery, the solar power generation device, and the fuel cell. [Figure 4] 10 is a diagram showing the power demand and the power generation target of the fuel cell during load following average power generation during load following averaging time t. FIG. [Figure 5] FIG. 10 is a diagram showing the relationship between load following averaging time and the amount of response delay of a fuel cell. [Figure 6] This is a diagram showing the change in PV power generation when there are many weather fluctuations. [Figure 7] This figure shows the change in PV power generation when there is little weather fluctuation. [Figure 8] FIG. 10 is a diagram showing the fuel cell power generation target value, current power generation value, and real-time required power (load-PV power generation) at load following averaging time t1 when there are many weather fluctuations. [Figure 9] FIG. 10 is a diagram showing the fuel cell power generation target value, current power generation value, and real-time required power (load-PV power generation) at load following averaging time t2 when there are many weather fluctuations. [Figure 10] FIG. 10 is a diagram showing the fuel cell power generation target value, current power generation value, and real-time required power (load-PV power generation) at load following averaging time t1 when there is little weather fluctuation. [Figure 11] FIG. 10 is a diagram showing the fuel cell power generation target value, current power generation value, and real-time required power (load-PV power generation) at load following averaging time t2 when there is little weather fluctuation. [Figure 12] FIG. 10 is a diagram showing the relationship between a weather change frequency forecast value and a load following averaging time t. [Figure 13] FIG. 10 is a diagram showing the overall configuration of a power supply system according to a second embodiment. [Figure 14] 10 is a flowchart showing the contents of an operation plan for a secondary battery according to a second embodiment. [Figure 15] 10 is a flowchart showing the contents of an EV charging plan according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment will be assigned the same reference numerals, and duplicated explanations may be omitted. In each embodiment, when only a part of the configuration is described, the other previously described embodiments may be applied to the other parts of the configuration.

[0014] In each embodiment, it is possible to combine parts that are specifically expressly possible to combine with each other. Furthermore, even if it is not expressly expressly possible to combine, it is also possible to partially combine embodiments with each other, embodiments with variations, and variations with each other, as long as there are no particular problems with the combination.

[0015] (First embodiment) The first embodiment will be described below with reference to the drawings. As shown in Fig. 1, a power supply system 10 includes a power demand 11, a grid power 12, a solar power generation device 13 (hereinafter, solar power generation will be referred to as PV power generation), a fuel cell 14, a secondary battery 15, a control unit 16, and a provider of weather data 17.

[0016] The power demand 11, grid power 12, PV power generation device 13, fuel cell 14, and secondary battery 15 are electrically connected by high-voltage electrical wiring. The control unit 16 is connected by wireless communication to the power demand 11, PV power generation device 13, fuel cell 14, secondary battery 15, and a provider of weather data 17. Of course, the control unit 16 may also be connected by wire to the power demand 11, PV power generation device 13, fuel cell 14, secondary battery 15, and a provider of weather data 17.

[0017] The power demand 11 is a facility or the like that requires power. The power demand 11 is capable of transmitting power information to the outside in real time using a monitoring device such as a power meter. The power information is information about the power used by the power demand load of the power demand 11.

[0018] A power demand load is a load of a facility or the like that consumes power. Typically, a power demand load operates on AC power. Therefore, when a power demand load receives power, DC power is converted into AC power.

[0019] The grid power 12 is power from a commercial grid. The grid power 12 is power purchased from an external source such as an electric power company. The type of power generation (fossil fuel, green power, etc.) of the power supplied from the grid power 12 does not matter.

[0020] The PV power generation device 13 is a device that generates power by irradiating sunlight onto a solar panel for converting light energy into electrical energy, and outputs DC power by generating electricity.

[0021] The fuel cell 14 is a device that generates electricity when supplied with fuel. The fuel cell 14 generates electricity, for example, by utilizing an electrochemical reaction between hydrogen as a fuel and oxygen as an oxidant. The fuel cell 14 has a stack structure in which a plurality of unit cells, each having an electrolyte sandwiched between a pair of electrodes, are stacked. The fuel cell 14 is, for example, a solid oxide fuel cell (SOFC) that uses an electrolyte made of an oxygen ion conductive oxide.

[0022] The fuel cell 14 is supplied with hydrogen from a fuel supply device, or fuel (e.g., city gas) is supplied to the fuel cell system, and hydrogen is extracted by internal reforming. The fuel supply device can be, for example, a hydrogen tank filled with high-pressure hydrogen. The amount of fuel or hydrogen supplied to the fuel cell 14 is controlled by a control unit 16.

[0023] In the fuel cell 14, an electrochemical reaction occurs between hydrogen and oxygen in the air, generating electrical energy. Of the hydrogen supplied to the fuel cell 14, unreacted hydrogen that is not used in the electrochemical reaction is discharged from the fuel cell 14 as exhaust gas. The fuel cell 14 generates power and outputs DC power.

[0024] The fuel cell 14 may be a polymer electrolyte fuel cell (PEFC) that uses an ion-conductive polymer membrane as an electrolyte.

[0025] The secondary battery 15 is a storage battery that can be charged and discharged. The secondary battery 15 forms a battery module in which multiple battery cells are connected in series. Each battery cell is, for example, a lithium-ion secondary battery. The secondary battery 15 is charged with DC power and outputs DC power by discharging.

[0026] The battery module may also include a configuration in which each battery cell is connected in parallel. In addition to a lithium ion battery, the secondary battery 15 may be a lead acid battery, a redox flow battery, or a battery capable of storing and discharging electric charge, such as a capacitor.

[0027] The control unit 16 controls the solar power generation device 13, the fuel cell 14, and the secondary battery 15 to supply power to the power demand load of the power demand 11. The control unit 16 is configured by, for example, an energy management system (EMS) terminal.

[0028] The control unit 16 is configured as, for example, a dedicated electronic device such as a computer or a server, or as software such as a cloud connected to the Internet, or an app, etc. Of course, the control unit 16 may also be configured as a system in which an electronic device and a cloud are integrated.

[0029] The control unit 16 sends a request for the device status to each of the PV power generation device 13, the fuel cell 14, and the secondary battery 15, and receives a response to the request. The control unit 16 also acquires information on the power demand load of the power demand 11, and responds to a request for power usage information.

[0030] In this embodiment, the control unit 16 obtains a power demand forecast of the power that will be required from the power demand 11 and a PV power generation forecast of the power that will be generated by the solar power generation device 13. The control unit 16 formulates an operation plan for operating the fuel cell 14, the PV power generation device 13, and the secondary battery 15 in response to the power demand 11 based on the power demand forecast and the PV power generation forecast. The control unit 16 then controls the operation of the fuel cell 14 to follow the power demand load of the power demand 11 based on the operation plan. The control unit 16 also controls the charging and discharging of the secondary battery 15, the fuel cell 14, and the power generation of the PV power generation device 13 based on the formulated operation plan for the secondary battery 15.

[0031] The weather data 17 is data indicating weather forecast information that is provided free of charge or for a fee. The weather data 17 is provided by the Japan Meteorological Agency or a private company. The weather data 17 indicates hourly weather information such as weather, solar radiation, temperature, cloud cover, and wind speed. The weather data 17 is periodically acquired by the control unit 16 via communication such as the Internet. The time interval for weather forecasting may be every minute or every hour. The forecast interval for periodic acquisition may be just for the current day, or may include the current day through tomorrow, or any other interval.

[0032] For example, weather forecast information is updated five times in 24 hours, at 11:00 PM, 3:00 AM, 6:00 AM, 12:00 PM, and 3:00 PM. The weather forecast information includes weather data such as sunny, cloudy, and rainy, as well as global solar radiation and temperature, presented at 30-minute intervals. In other words, the weather for one day is represented by 48 frames. The control unit 16 periodically acquires weather forecast information for the current day, the next day, and the day after that. This completes the overall configuration of the power supply system 10.

[0033] FIG. 2 is a flowchart showing the content of determining an operation plan for the secondary battery 15 in the power supply system 10. The flowchart in FIG. 2 is executed by the control unit 16 and starts each time the timing at which weather forecast information is acquired or the date is updated. The operation plan for the day is completed at the latest by the time the secondary battery 15 reaches daytime surplus power generation. For example, it is completed between midnight and 3:00 AM.

[0034] 3 is a flowchart showing the contents of charge / discharge of the secondary battery 15 and power generation control of the fuel cell 14 and the PV power generation device 13. The flowchart in FIG.

[0035] First, the operation plan of the secondary battery 15 in Fig. 2 will be described. In step S110, the control unit 16 externally acquires weather data 17 including weather forecast information. The control unit 16 acquires the information at intervals at which the weather forecast information is updated.

[0036] In step S120, the control unit 16 acquires a power demand forecast. For example, the control unit 16 calculates the power demand forecast based on the results of statistics using either or both of the weather forecast information acquired in step S110 and the past power demand record of the power demand 11, or the results of machine learning.

[0037] As the past power demand record, data for various periods can be used, such as yesterday's power demand record, last week's power demand record, one month's power demand record, several months' power demand record, yearly power demand record, etc. Weather forecast information includes, for example, solar radiation and temperature.

[0038] The control unit 16 may calculate the power demand forecast using past operation plans in addition to the weather forecast information and past power demand results.

[0039] In step S130, the control unit 16 acquires a PV power generation amount prediction. The control unit 16 executes hourly PV power generation amount prediction based on, for example, weather forecast information. The control unit 16 also calculates the PV power generation amount using the number of solar panels, capacity, correction coefficient, solar radiation, temperature, etc.

[0040] In step S140, a required discharge amount prediction A is obtained, which indicates the amount of discharge from the secondary battery 15 that will be required to compensate for the power generation response delay of the fuel cell 14. The power generation response delay of the fuel cell 14 is caused by a lack of output power due to the inability to suddenly change the amount of power generated by the fuel cell 14, which is due to the power generation principle of the fuel cell 14. In order to compensate for this power generation response delay of the fuel cell 14 by discharging the secondary battery 15, the control unit 16 calculates how much discharge amount is required from the secondary battery 15.

[0041] 4, the power required by the power demand 11 changes over time. For example, if the integrated value of the power required within a time t is Σ load, the power generation target of the fuel cell 14 after the time t has elapsed is expressed as (Σ load / time t).

[0042] The power generation target of the fuel cell 14 is to generate power equal to the power generation target at time t before the power currently requested by the power demand 11. That is, the control unit 16 determines the power generation target of the fuel cell 14 as a load following average. Time t is the load following averaging time. In this way, the fuel cell 14 generates power with a delay so as to follow the power requested by the current power demand 11. Therefore, in step S140, the discharge amount of the secondary battery 15 is predicted in advance when there is currently insufficient power to meet the power demand 11.

[0043] 5, the response delay of the fuel cell 14 changes depending on weather fluctuations. For example, when the load following averaging time t of the power generation target is short (t1), the response delay of the fuel cell 14 is greater when there is a lot of weather fluctuation than when there is little weather fluctuation. On the other hand, when the load following averaging time t of the power generation target is long (t2), the difference in the response delay of the fuel cell 14 between when there is a lot of weather fluctuation and when there is little weather fluctuation becomes smaller.

[0044] The control unit 16 calculates an index indicating the load factor fluctuation frequency based on, for example, weather forecast information, PV power generation forecast, and power demand forecast, and calculates a required discharge amount forecast A of the secondary battery 15 that compensates for the power generation response delay of the fuel cell 14 based on the index. The load factor fluctuation frequency indicates the degree of fluctuation in the load factor of the fuel cell 14. The load factor of the fuel cell 14 can be calculated, for example, from (power of power demand forecast - power of PV power generation forecast) / (rated power of the fuel cell 14).

[0045] Here, because the fuel cell 14 has a relatively long power generation response time, the amount of adjustment by the secondary battery 15 varies depending on, for example, the frequency of fluctuations in PV power generation. For example, as shown in Fig. 6, when there are many weather fluctuations, the amount of power generated by PV power generation fluctuates greatly. In contrast, as shown in Fig. 7, when there are few weather fluctuations, the amount of power generated by PV power generation fluctuates little and is stable.

[0046] 8 and 9 show the target power generation value and current power generation value of the fuel cell 14 when there are frequent weather fluctuations. As shown in FIG. 8, when the load following averaging time is t1, there is a large fluctuation in the target power generation value of the fuel cell 14. Also, the current power generation value of the fuel cell 14 lags significantly behind the target power generation value. Note that the load-PV power generation is the power required in real time. As shown in FIG. 9, when the load following averaging time is t2, which is longer than t1, the current power generation value of the fuel cell 14 has less power generation response delay than at t1, but still lags significantly behind the target power generation value, just like at t1.

[0047] In contrast, Figures 10 and 11 show the target power generation value and current power generation value of the fuel cell 14 when there is little weather fluctuation. As shown in Figures 10 and 11, when there is little weather fluctuation, there is little fluctuation in the target power generation value of the fuel cell 14 whether the load following averaging time is t1 or t2. Also, the current power generation value of the fuel cell 14 lags only slightly behind the target power generation value. Note that in Figures 8 to 11, in addition to PV power generation, load factor fluctuations due to the power demand 11 itself are also assumed.

[0048] This step is incorporated into the operation planning flow, focusing on the fact that the power generation response delay of the fuel cell 14 operating in load following mode correlates with fluctuations in PV power generation, i.e., weather fluctuations, and is the total power generation required of the secondary battery 15. This step makes it possible to predict how much the secondary battery 15 will discharge in order for it to assist the fuel cell 14. It can also be used to improve the accuracy of peak cut control of the secondary battery 15, and to manage and control the remaining capacity of the secondary battery 15, which reduces power generation costs and CO2 emissions.

[0049] In step S150, the control unit 16 acquires a grid power usage forecast B that predicts the usage amount of the external grid power 12. The control unit 16 calculates the hourly grid power usage forecast B based on, for example, the PV power generation forecast, the power demand forecast, and the rated power generation amount of the fuel cell 14, on the assumption that the secondary battery 15 will not discharge. The power demand forecast is the power that will be required from the power demand load of the power demand 11, and is a load forecast.

[0050] In step S160, the control unit 16 acquires a PV power generation surplus prediction C of power that will be extra generated by the photovoltaic power generation device 13. The control unit 16 calculates the PV power generation surplus prediction C for each hour based on, for example, the PV power generation amount prediction and the load prediction. Specifically, the control unit 16 calculates the PV power generation surplus prediction C as C = (PV power generation amount prediction - power demand prediction).

[0051] In step S170, the control unit 16 acquires the fluctuation in the load factor of the fuel cell 14, which is likely to change over time, as the load factor fluctuation prediction D. As described above, the control unit 16 can acquire the load factor fluctuation prediction D by calculating the load factor of the fuel cell 14 for each prediction time from the difference between the power demand prediction and the PV power generation prediction. Alternatively, the control unit 16 can acquire the load factor fluctuation prediction D using one or more of the weather forecast changes in weather conditions, cloud cover changes, and solar radiation included in the weather data 17 acquired from the outside. Using more than one includes using two items, such as weather conditions and cloud cover changes, or cloud cover changes and solar radiation, and using three items, such as weather conditions, cloud cover changes, and solar radiation.

[0052] For example, when the load factor of the fuel cell 14 is 100% or more, the fuel cell 14 generates rated power. When the load factor of the fuel cell 14 is 0%, the fuel cell 14 is in a standby state. For example, the fuel cell 14 stops generating power when the power demand load drops for a long period of time.

[0053] Here, in step S140, the control unit 16 can determine the predicted discharge amount A required for the secondary battery 15 based on the predicted load rate fluctuation D for the fuel cell 14. The control unit 16 predicts that the predicted discharge amount A will be larger as the predicted load rate fluctuation D for the fuel cell 14 becomes larger.

[0054] In step S180, the control unit 16 calculates a peak cut target value for the secondary battery 15 to reduce power usage of the secondary battery 15 during peak hours. The control unit 16 includes a peak cut plan for the secondary battery 15 in the charge / discharge plan for the secondary battery 15, and can set the peak cut target for the secondary battery 15 based on a power demand forecast and a PV power generation amount forecast. The control unit 16 can determine the target remaining battery capacity of the secondary battery 15 based on, for example, the sum of a required discharge amount forecast A and a grid power usage forecast B.

[0055] Alternatively, the control unit 16 can set a peak cut target for the secondary battery 15 based on the predicted discharge amount of the secondary battery 15 for that day, which is determined from the sum of the predicted discharge requirement amount A and the predicted grid power usage B, and the SOC (State Of Charge) of the secondary battery 15. That is, the control unit 16 can calculate the peak cut target value for the secondary battery from Target Value = {(A + B) - SOC of secondary battery 15}. If the value obtained by this formula is negative, the peak cut target value becomes 0. In this way, the control unit 16 includes a plan for peak cut for the secondary battery 15 in the plan for charging and discharging the secondary battery 15.

[0056] In this step, it is possible to set a target value for peak shaving control that can be implemented on that day, taking into account the amount required to accommodate delays in the power generation response of the fuel cell 14, the estimated purchase amount of grid power 12 that takes into account PV power generation and the rated power generation of the fuel cell 14, and the SOC of the secondary battery 15. This makes it possible to improve the accuracy of peak shaving control of the secondary battery 15.

[0057] In step S190, the control unit 16 determines a main discharge time for discharging the secondary battery 15 to the power demand load with priority over the fuel cell 14 based on the PV power generation surplus prediction C and the SOC of the secondary battery 15.

[0058] For this reason, the control unit 16 obtains the currently chargeable amount of power stored from the difference between the maximum SOC of the secondary battery 15 and the current SOC, the sum of the PV power generation surplus prediction C at each time within a predetermined time range, and the time period within the predetermined time range during which the PV power generation surplus prediction C becomes positive. Then, the control unit 16 determines the time period during which the secondary battery 15 is preferentially discharged before the time period during which the PV power generation surplus prediction C becomes positive, so that the secondary battery 15 can be charged with power based on the sum of the PV power generation surplus prediction C.

[0059] For example, if a day is divided into 48 frames, the predicted surplus PV power generation C for one day is the sum of the surplus PV power generation for the 48 frames. The control unit 16 acquires the time period Tc during which surplus PV power generation is produced by the PV power generation device 13, such as the start and end time. The control unit 16 also calculates the difference (SOCmax-SOC) between SOCmax, which is the maximum battery capacity, and the current remaining battery capacity SOC, thereby calculating how much power can be stored in the secondary battery 15 from its current state.

[0060] Then, in order to charge the secondary battery 15 with as much surplus PV power generation as possible, the control unit 16 frees up capacity in the secondary battery 15 for charging the surplus PV power generation by the time slot when the surplus PV power generation occurs. That is, the control unit 16 determines what time to start discharging the secondary battery 15 so that the surplus PV power generation can be freed up in the secondary battery 15. Therefore, the control unit 16 starts discharging the secondary battery 15 from a time slot (Tc-n) that is n hours earlier than the time slot Tc when the surplus PV power generation occurs. In this way, the control unit 16 includes in the charge / discharge plan for the secondary battery 15 a plan to discharge the secondary battery 15 to a power demand load with priority over the fuel cell 14.

[0061] When surplus PV power generation is expected and the remaining capacity of secondary battery 15 is large, there is a possibility that the surplus PV power generation will be wasted (when there is no reverse current). However, in this step, in order to avoid wasting the surplus PV power generation, it is possible to calculate backwards from the time when the surplus PV power generation will occur and the power demand 11, and determine a priority discharge time so that the surplus PV power generation can be sufficiently stored in secondary battery 15 without the capacity of secondary battery 15 becoming empty. Therefore, it is possible to reduce power generation costs and the CO2 emission coefficient by effectively utilizing the surplus PV power generation.

[0062] In step S200, the control unit 16 determines the power generation time of the fuel cell 14 for charging the secondary battery 15 from the fuel cell 14.

[0063] For example, when the predicted value of the total discharge amount of secondary battery 15 is greater than the current SOC of secondary battery 15 and the surplus power generation to secondary battery 15 based on the PV power generation surplus prediction C is insufficient, control unit 16 sets the amount of power including the power to the power demand load and the amount charged to secondary battery 15 as the power generation target of fuel cell 14 and determines the power generation time of fuel cell 14 for charging secondary battery 15. The predicted value of the total discharge amount of secondary battery 15 can be calculated, for example, as predicted value of total discharge amount = A + Σ (Bi - peak cut target value), where Bi is the hourly grid power usage prediction B.

[0064] The control unit 16 can select a time period with a small load factor fluctuation prediction D. Furthermore, the control unit 16 can preferentially select a time period late at night on the day or a time period during the day when the PV power generation device 13 is operating.

[0065] Furthermore, when the charge amount of the secondary battery 15 due to power generation by the fuel cell 14 is insufficient, the control unit 16 causes the fuel cell 14 to generate power at night rather than during the day based on the grid power usage prediction B. This makes it possible to plan the charge amount of the secondary battery 15 so that the peak usage of the grid power 12 is evened out.

[0066] To compensate for the insufficient charge in the secondary battery 15, the nighttime system where electricity is cheap is used within a range where the grid power 12 is below the peak cut target value, and the secondary battery 15 is charged. This step enables the operation and management of the secondary battery 15 while suppressing the power generation cost of the power supply system 10 and CO2 emissions.

[0067] In step S210, the control unit 16 determines the load following averaging control time for the fuel cell 14. That is, the control unit 16 determines the load following averaging time t.

[0068] The control unit 16 can determine the load following averaging time for calculating the load following average based on the load factor fluctuation prediction D. The control unit 16 sets the load following averaging time t to be long when the load factor fluctuation frequency, which indicates the degree of fluctuation in the load factor of the fuel cell 14, is large, and sets the load following averaging time t to be short when the load factor fluctuation frequency is small. The control unit 16 can obtain the load factor fluctuation frequency based on an accumulation of the differential value of the load factor of the fuel cell 14.

[0069] Based on the frequency with which weather changes from cloudy or rainy to sunny, the control unit 16 can obtain a load factor fluctuation frequency that indicates the degree of fluctuation in the load factor of the fuel cell 14. In other words, the load factor fluctuation frequency can be said to be a weather change frequency prediction value.

[0070] 12, the smaller the weather change frequency forecast value, the shorter the load following averaging time t is set, and the larger the weather change frequency forecast value, the longer the load following averaging time t is set. This makes it possible to reduce the amount of assistance provided by the secondary battery 15 or to suppress the use of the grid power 12.

[0071] The predicted required discharge amount A of the secondary battery 15 in step S140 and the predicted weather change frequency value in step S210 can be determined as follows.

[0072] First, the control unit 16 can add the load factor fluctuation frequency (weather change frequency predicted value) when the load factor of the fuel cell 14 changes to a positive value. Specifically, the response delay can be estimated from the deviation of the load factor of the fuel cell 14. The deviation represents how much the load factor has changed from the previous load factor state to the current load factor state. For example, when the weather changes from rainy to sunny to rainy, the load changes from heavy load to no load to heavy load, with a small deviation from heavy load to no load and a large deviation from no load to heavy load. The deviation from light load to heavy load, which results in a large response delay of the fuel cell 14, is integrated (added) to the load factor fluctuation frequency.

[0073] Second, the control unit 16 can directly calculate the predicted value of the frequency of weather changes based on the weather forecast, and calculate the predicted required discharge amount A of the secondary battery 15. For this reason, the control unit 16 receives the weather forecast with a resolution of one hour, such as sunny at 8:00, sunny at 9:00, cloudy at 10:00, sunny at 11:00, cloudy at 12:00, rainy at 13:00, sunny at 14:00, etc. By viewing the weather every hour, the frequency of weather changes occurs several times. In other words, it is possible to directly quantify the frequency of weather changes. Therefore, the control unit 16 greatly controls the predicted required discharge amount A of the secondary battery 15 according to the frequency count.

[0074] Third, the control unit 16 can calculate the predicted required discharge amount A of the secondary battery 15 based on the predicted surplus PV power generation C acquired in step S160. The existence of surplus PV power generation in the PV power generation device 13 means that the load factor of the fuel cell 14 is small. Conversely, the absence of surplus PV power generation in the PV power generation device 13 means that the load factor of the fuel cell 14 is large. Note that when PV power generation exceeds the power demand load, the fuel cell 14 goes into standby mode, resulting in the slowest power generation response of the fuel cell 14. Therefore, there is an advantage to calculating the predicted required discharge amount A of the secondary battery 15 in advance from the surplus PV power generation.

[0075] Fourth, the control unit 16 may combine the first and second features described above.

[0076] Fifth, in relation to the second aspect above, the control unit 16 may count the frequency of weather changes based on the amount of cloud cover.

[0077] Sixth, the control unit 16 may count the frequency of weather changes only during the time period when there is global solar radiation, with respect to the first to fifth contents described above.

[0078] Seventh, in the sixth aspect described above, the control unit 16 may also calculate the predicted discharge amount A required for the secondary battery 15 from predicted information on global solar radiation.

[0079] As described above, the control unit 16 plans the charging and discharging of the secondary battery 15 based on the discharge requirement prediction A, the grid power usage prediction B, the PV power generation surplus prediction C, and the load factor fluctuation prediction D, and plans the operation of the fuel cell 14 based on the plan for charging and discharging the secondary battery 15.

[0080] Next, the charging and discharging of the secondary battery 15, and the power generation control of the PV power generation device 13 and the fuel cell 14 based on the above-mentioned operation plan will be described.

[0081] 3, the control unit 16 acquires the current values ​​of the power demand load of the power demand 11, and the power generation equipment, that is, the PV power generation device 13 and the fuel cell 14. The current values ​​are the power currently required by the power demand load, the current power generation amount of the PV power generation device 13, and the current power generation amount of the fuel cell 14.

[0082] Next, in step S320, the control unit 16 determines whether there is surplus power supply relative to the power demand 11. That is, the control unit 16 determines whether the current amount of power generated by the power generator acquired in step S310 is greater than the power required by the power demand 11. In this step, if the current amount of power generated by the power generator is greater than the power required by the power demand 11, the process proceeds to step S330.

[0083] In step S330, the control unit 16 sets the charge amount of the secondary battery 15. That is, the control unit 16 sets the secondary battery 15 to be charged with surplus power from the power generation equipment. When suppressing reverse power flow to the grid power 12, the control unit 16 suppresses the output in the order of fuel cell 14 > PV power generation device 13. That is, the control unit 16 reduces the output of the fuel cell 14. After this, the process returns to step S310, and the flow is repeated.

[0084] In step S320, if the current amount of power generated by the power generation equipment is less than the power required by the power demand 11, the process proceeds to step S340.

[0085] In step S340, the control unit 16 determines whether or not to prioritize discharging the secondary battery 15 based on the main discharge time of the secondary battery 15 acquired in step S190. For example, the control unit 16 determines whether or not the current time is a time period in which the secondary battery 15 is to be prioritized for discharge. If it is determined in this step that the current time period is a time period in which the secondary battery 15 is to be prioritized for discharge, the process proceeds to step S350.

[0086] In step S350, the control unit 16 determines the power generation priority order of the fuel cell 14 and the secondary battery 15 that supply power to the power demand 11 based on the PV power generation surplus prediction C and the SOC of the secondary battery 15 in accordance with the operation plan.

[0087] During the time period when the secondary battery 15 is to be preferentially discharged over the fuel cell 14, the control unit 16 sets the power generation priority order for the power demand load to be the photovoltaic power generation device 13, the secondary battery 15, and the fuel cell 14. Although it is determined in step S340 that the secondary battery 15 is to be preferentially discharged, the PV power generation device 13 is given priority over the secondary battery 15 because the PV power generation device 13 can generate power at low cost.

[0088] Therefore, the fuel cell 14 is in a state where power generation is suppressed or is on standby because discharge of the secondary battery 15 to the power demand 11 takes priority. Furthermore, since surplus PV power generation is expected from the PV power generation device 13 and the SOC of the secondary battery 15 is excessive, the secondary battery 15 is put into a state where discharge is prioritized over the fuel cell 14 in response to the power demand load. After this, the process proceeds to step S400.

[0089] If it is determined in step S340 that it is not a time period in which the secondary battery 15 is to be preferentially discharged, the process proceeds to step S360.

[0090] In step S360, the control unit 16 determines whether or not to charge the secondary battery 15 using the fuel cell 14. The control unit 16 determines whether or not to generate power using the fuel cell 14 based on the power generation time of the fuel cell 14 acquired in step S200 described above. If it is determined in this step that the secondary battery 15 is to be charged using the fuel cell 14, the process proceeds to step S370.

[0091] In this way, when the process proceeds to step S350, power is supplied to the power demand 11 in the order of secondary battery 15 > fuel cell 14, and when the process proceeds to step S360, power is supplied from the fuel cell 14 to the power demand 11. In this way, the power generation priority order between the fuel cell 14 and secondary battery 15 may be reversed depending on the operation plan.

[0092] In step S370, the control unit 16 sets an output target for the fuel cell 14. That is, the fuel cell 14 is in a state of generating power at a power generation target value obtained by adding the charge amount of the secondary battery 15 to the load following average in order to charge the secondary battery 15. Therefore, the control unit 16 sets the output target to, for example, (power amount of the power demand load + charge amount of the secondary battery 15 - PV power generation amount).

[0093] Thereafter, in step S380, similar to step S320, control unit 16 determines whether there is surplus power supply for power demand 11. If it is determined that there is no surplus power supply, the process proceeds to step S400.

[0094] If it is determined that there is surplus power to be supplied, the process proceeds to step S330. That is, the secondary battery 15 is in a state where it is charged by the fuel cell 14 when there is surplus power generation in the fuel cell 14.

[0095] If it is determined in step S360 that the secondary battery 15 is not to be charged by the fuel cell 14, the process proceeds to step S390.

[0096] In step S390, the control unit 16 controls the fuel cell 14 to perform load-following average power generation. As a result, the fuel cell 14 enters a state in which the power generation target of the fuel cell 14 is determined by load-following average with respect to the power demand load in accordance with step S210. Then, the process proceeds to step S400.

[0097] In step S400, the control unit 16 determines whether or not peak cut discharge is necessary for the secondary battery 15. That is, the control unit 16 determines whether or not a peak cut target value has been set for the secondary battery 15 in step S180. If a peak cut target value has not been set, the process returns to step S310.

[0098] On the other hand, if a peak cut target value has been set, the process proceeds to step S410. In step S410, the control unit 16 sets a peak cut target value for the secondary battery 15 and controls the discharge of the secondary battery 15 in accordance with the target value.

[0099] Therefore, the secondary battery 15 assumes a state of load-following discharge based on a predetermined peak cut target to make up for the shortfall in the PV power generation by the PV power generation device 13 and the power generation by the fuel cell 14 with respect to the power demand load. Then, the process returns to step S310.

[0100] As described above, in this embodiment, an operation plan for the secondary battery 15 and a charging plan for the fuel cell 14 are made according to the operation plan flow shown in Fig. 2. Furthermore, according to the control flow shown in Fig. 3, power is supplied in the order of PV power generation system 13 > fuel cell 14 > secondary battery 15, following the power demand load in real time. If surplus PV power generation is expected in the flow of Fig. 2, the power supply priority is reversed to the order of PV power generation system 13 > secondary battery 15 > fuel cell 14.

[0101] The discharge amount of the secondary battery 15 that compensates for the load following delay of the fuel cell 14 can be appropriately charged to the secondary battery 15 using the PV power generation surplus of the PV power generation device 13 and the minimum power generation surplus of the fuel cell 14. This eliminates the need for an excessive installation of the secondary battery 15. This makes it possible to reduce capital investment in the secondary battery 15, and ultimately minimize capital investment in the power supply system 10.

[0102] 2, the order of steps S120 and S130 may be interchanged. The order of steps S140, S150, S160, and S170 may be interchanged. The order of steps S180, S190, S200, and S210 may be interchanged. Alternatively, the processing order of steps S140 to S210 may be interchanged.

[0103] (Second embodiment) In this embodiment, differences from the first embodiment will be mainly described. FIG. 13 shows the overall configuration of a power supply system 10 according to this embodiment. As shown in FIG. 13, the power supply system 10 includes a power storage capacity connected by V2X 18 (Vehicle to X) in addition to the configuration shown in FIG. 1. V2X 18 refers to technology for communication and cooperation between a vehicle and various things. It can be said that V2X 18 is a power transfer device for the system.

[0104] The power storage capacity is, for example, an in-vehicle secondary battery 19 mounted on the vehicle. The in-vehicle secondary battery 19 is not limited to a lithium-ion battery, but may be a lead battery. Furthermore, the power storage capacity is not limited to the in-vehicle secondary battery 19, but may also include storage batteries such as V2H (Vehicle to Home) and V2G (Vehicle to Grid). V2G and V2H are systems that electrically connect an electric vehicle and the power system of the power supply system 10 to effectively utilize each other's power. Note that the number of power storage capacities connected to the power supply system 10 by V2X 18 is not limited to one, but may be multiple.

[0105] Based on the EV operation plan, the control unit 16 adds the SOC of the in-vehicle secondary battery 19 that is not scheduled for operation to the SOC of the stationary secondary battery 15, and controls the secondary battery 15 and the in-vehicle secondary battery 19.

[0106] Next, the determination of the operation plan for the secondary battery 15 according to this embodiment will be described with reference to Fig. 14. The difference from the flowchart in Fig. 2 is that steps S115 and S175 have been added.

[0107] After step S110, in step S175, the control unit 16 acquires an EV operation plan for the in-vehicle secondary battery 19. The EV operation plan is a usage schedule for the in-vehicle secondary battery 19, such as when the in-vehicle secondary battery 19 will be used and from what time to what time it will be used. The usage schedule is managed, for example, in the vehicle in which the in-vehicle secondary battery 19 is installed, or externally, such as on the computer of the user who owns the vehicle in which the in-vehicle secondary battery 19 is installed, or on the cloud. Therefore, the control unit 16 acquires the usage schedule for the in-vehicle secondary battery 19 as the EV operation plan. Note that the control unit 16 may also manage the EV operation plan for the in-vehicle secondary battery 19. Then, the process proceeds to step S120.

[0108] After step S170, in step S175, the control unit 16 acquires an EV charging plan for the in-vehicle secondary battery 19. The control unit 16 acquires a power demand forecast excluding charging of the in-vehicle secondary battery 19, a load factor fluctuation forecast D, and a grid power usage forecast B, and creates an EV charging plan for the in-vehicle secondary battery 19 based on these. The EV charging plan for the in-vehicle secondary battery 19 is created according to the EV charging plan flow shown in Fig. 15.

[0109] In step S500, the control unit 16 determines whether the amount of charge required for the vehicle-mounted secondary battery 19 is greater than the PV power generation surplus prediction C. The control unit 16 uses the PV power generation surplus prediction C calculated in step S350. If the amount of charge required for the vehicle-mounted secondary battery 19 is less than the PV power generation surplus prediction C, the process proceeds to step S510.

[0110] In step S510, the control unit 16 formulates a plan to charge the in-vehicle secondary battery 19 using surplus PV power generation. For example, even if the in-vehicle secondary battery 19 needs to be charged, if use is planned for the next day or later, the control unit 16 lowers the charging priority of the in-vehicle secondary battery 19 and schedules charging using surplus PV power generation. After this, the process returns to step S500.

[0111] In step S500, if it is determined that the amount of charge required for the vehicle-mounted secondary battery 19 is greater than the predicted PV power generation surplus C, the process proceeds to step S520.

[0112] In step S520, the control unit 16 determines whether the power of (required charging amount - predicted surplus PV power generation C) can be charged by the fuel cell 14, based on the current operating state or standby state of the fuel cell 14. If it is determined that the power can be charged by the fuel cell 14, the process proceeds to step S530.

[0113] In step S530, the control unit 16 creates a charging plan for the vehicle-mounted secondary battery 19 according to the priority order of surplus PV power generation, fuel cell 14, and grid power 12. As a result, the vehicle-mounted secondary battery 19 is planned to be charged according to a schedule that suppresses the peak of the grid power 12. After this, the process returns to step S500.

[0114] If it is determined in step S520 that charging is not possible using the fuel cell 14, the process proceeds to step S540.

[0115] In step S540, the control unit 16 creates a charging plan for the in-vehicle secondary battery 19 based on the priority of PV power generation surplus and the fuel cell 14. For example, if the in-vehicle secondary battery 19 needs to be charged and the in-vehicle secondary battery 19 is planned to be used from the next day onwards, the control unit 16 lowers the charging priority of the in-vehicle secondary battery 19 and creates a charging plan for the in-vehicle secondary battery 19 so that the in-vehicle secondary battery 19 is charged using PV power generation surplus based on the PV power generation surplus prediction C or power generation by the fuel cell 14. After this, the process returns to step S500 and repeatedly creates an EV charging plan. After acquiring the EV charging plan in step S175, the process proceeds to step S180.

[0116] As described above, even when another power storage capacity such as the in-vehicle secondary battery 19 is connected to the power supply system 10 by the V2X 18, the capital investment for the secondary battery 15 can be reduced, as in the first embodiment.

[0117] 14, the order of steps S120, S115, and S130 may be interchanged, and the order of steps S175, S180, S190, S200, and S210 may be interchanged.

[0118] Regarding the correspondence between the description of this embodiment and the description of the claims, the in-vehicle secondary battery 19 corresponds to the "electricity storage capacity" in the claims.

[0119] (Other embodiments) The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure.

[0120] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure. [Explanation of symbols]

[0121] 10 Power Supply System 11 Electricity demand 12 Grid power 13. Solar power generation equipment 14 Fuel Cell 15 Secondary battery 16 Control Unit 17 Weather Data 18 V2X 19 Automotive secondary batteries

Claims

1. a solar power generation device (13) that generates electricity by being irradiated with sunlight; a fuel cell (14) that generates electricity when supplied with fuel; a secondary battery (15) that can be charged and discharged; a control unit (16) that controls the solar power generation device, the fuel cell, and the secondary battery; Including, The control unit obtains a power demand forecast of the power that will be required from the power demand (11) and a solar power generation forecast of the power that will be generated by the solar power generation device, and creates an operation plan for operating the fuel cell, the solar power generation device, and the secondary battery in response to the power demand based on the power demand forecast and the solar power generation forecast, and controls the operation of the fuel cell to follow the power demand load of the power demand based on the operation plan.

2. The control unit Obtaining weather data (17) from an external source; 2. The power supply system according to claim 1, wherein the power demand forecast is obtained based on a result of statistics or a result of machine learning using either or both of weather forecast information based on the weather data and past power demand results of the power demand.

3. The control unit Obtaining a load factor fluctuation prediction of the fuel cell that will likely change over time; The power supply system according to claim 1 , wherein the operation plan includes planning charging and discharging of the secondary battery based on the load factor fluctuation prediction, and planning operation of the fuel cell based on the plan for charging and discharging of the secondary battery.

4. The control unit Obtaining a load factor fluctuation prediction of the fuel cell that will likely change over time; determining a power generation target of the fuel cell as a load following average, and determining an averaging time for calculating the load following average based on the load factor fluctuation prediction; 2. The power supply system according to claim 1, wherein the averaging time is set to be long when the load rate fluctuation frequency, which indicates the degree of fluctuation in the load rate of the fuel cell, is large, and the averaging time is set to be short when the load rate fluctuation frequency is small.

5. The control unit obtaining a solar power surplus forecast of power that will be extra generated by the solar power generation device; In the operation plan, a power generation priority order of the fuel cell and the secondary battery that supply power to the power demand is determined based on the solar power generation surplus prediction and the SOC of the secondary battery; The power supply system according to claim 1 , wherein the power generation priority order of the fuel cell and the secondary battery is reversed according to the operation plan.

6. The control unit Obtaining a load factor fluctuation prediction of the fuel cell that will likely change over time; In the operation plan, charging and discharging of the secondary battery is planned based on the load factor fluctuation prediction; The fuel cell comprises: a state in which a power generation target of the fuel cell is determined by load following averaging with respect to the power demand load; a state in which power generation is suppressed or power generation is put on hold by prioritizing discharge of the secondary battery to meet the power demand based on a charge / discharge plan for the secondary battery; a state in which power is generated at a power generation target value obtained by adding the charge amount of the secondary battery to the load following average in order to charge the secondary battery; a state in which power generation is stopped when the power demand load decreases for a long period of time; The power supply system according to claim 1 , wherein the power supply system has the following states:

7. The secondary battery is a state in which a shortage of photovoltaic power generation by the photovoltaic power generation device and power generation by the fuel cell is compensated for by load-following discharge based on a predetermined peak cut target, in response to the power demand load; a state in which the fuel cell is charged when there is a surplus of fuel cell power generation in the fuel cell; a state in which, when surplus solar power generation is expected in the solar power generation device and the SOC of the secondary battery is excessive, the secondary battery is discharged with priority over the fuel cell to the power demand load; The power supply system according to claim 1 , wherein the power supply system has the following states:

8. 4. The power supply system according to claim 3, wherein the control unit obtains the load factor fluctuation prediction by calculating the load factor of the fuel cell for each prediction time from the difference between the power demand prediction and the solar power generation prediction, and obtains the load factor fluctuation frequency based on an accumulation of a differential value of the load factor of the fuel cell.

9. The control unit Obtaining weather data (17) from an external source; The power supply system according to claim 3 , wherein the load factor fluctuation prediction is obtained using one or more of a weather condition change, a cloud cover change, and solar radiation in a weather forecast included in the weather data.

10. 9. The power supply system according to claim 8, wherein the control unit increases the load factor fluctuation frequency when the load factor of the fuel cell changes to a positive value.

11. 10. The power supply system according to claim 9, wherein the control unit acquires a load factor fluctuation frequency indicating a degree of fluctuation in the load factor of the fuel cell based on a frequency at which weather corresponding to cloudy or rainy weather changes to sunny weather.

12. The control unit a required discharge amount prediction indicating the amount of discharge of the secondary battery that will be required to compensate for the power generation response delay of the fuel cell, a grid power usage prediction that predicts the amount of usage of external grid power (12), and a solar power generation surplus prediction of power that will be extraneously generated by the solar power generation device are respectively obtained; The power supply system according to claim 3 , wherein charging and discharging of the secondary battery is planned based on the required discharge amount prediction, the grid power usage prediction, and the photovoltaic power generation surplus prediction.

13. The power supply system according to claim 12 , wherein the control unit determines a target remaining battery level of the secondary battery based on a sum of the predicted required discharge amount and the predicted grid power usage.

14. The power supply system according to claim 12 , wherein the control unit determines the required discharge amount prediction based on the load factor fluctuation prediction, and predicts the required discharge amount to be larger as the load factor fluctuation prediction increases.

15. The power supply system according to claim 12 , wherein the control unit determines the grid power usage prediction based on the power demand prediction, the solar power generation amount prediction, and a rated power generation amount of the fuel cell.

16. 4. The power supply system according to claim 3, wherein the control unit includes a plan for peak shaving of the secondary battery in a plan for charging and discharging the secondary battery, and sets a peak shaving target for the secondary battery based on the power demand forecast and the solar power generation forecast.

17. The control unit The charge / discharge plan for the secondary battery includes a peak shaving plan for the secondary battery, a required discharge amount prediction indicating the discharge amount of the secondary battery that will be required to compensate for the power generation response delay of the fuel cell, and a grid power usage prediction predicting the usage amount of external grid power (12); 4. The power supply system according to claim 3, wherein a peak cut target for the secondary battery is set based on a predicted discharge amount of the secondary battery on the day determined from a sum of the predicted discharge requirement amount and the predicted grid power usage amount, and an SOC of the secondary battery.

18. The control unit the charge / discharge plan for the secondary battery includes a plan for discharging the secondary battery to the power demand load in priority to the fuel cell; obtaining a solar power surplus forecast of power that will be extra generated by the solar power generation device; determining a time for discharging the secondary battery to the power demand load in preference to the fuel cell based on the solar power generation surplus prediction and the SOC of the secondary battery; 4. The power supply system according to claim 3, wherein during a time period in which the secondary battery is preferentially discharged over the fuel cell, the power generation priority order for the power demand load is set to the solar power generation device, the secondary battery, and the fuel cell in that order.

19. The control unit obtain a currently chargeable amount of stored power from a difference between a maximum SOC and a current SOC of the secondary battery, a sum of the predicted surplus photovoltaic power generation at each time within a predetermined time range, and a time period within the predetermined time range in which the predicted surplus photovoltaic power generation becomes positive; 19. The power supply system according to claim 18, wherein a time period during which the secondary battery is preferentially discharged is determined before a time period during which the solar power generation surplus prediction becomes positive, so that the secondary battery can be charged with power based on a sum of the solar power generation surplus predictions.

20. The control unit obtaining a solar power surplus forecast of power that will be extra generated by the solar power generation device; 17. The power supply system according to claim 16, wherein, when a predicted value of the total discharge amount of the secondary battery is greater than a current SOC of the secondary battery and surplus power generation to the secondary battery based on the predicted surplus solar power generation is insufficient, a power generation target of the fuel cell is set to an amount of power including power to the power demand load and power charged to the secondary battery, and a power generation time of the fuel cell for charging the secondary battery is determined.

21. The control unit Obtain a grid power usage forecast that predicts the usage of external grid power (12); When charging the secondary battery using the fuel cell, a time period when the load factor of the fuel cell is small is selected; 21. The power supply system according to claim 20, wherein, when the charge amount of the secondary battery due to power generation by the fuel cell is insufficient, the charge amount of the secondary battery is planned so that peak usage of the grid power is equalized by having the fuel cell generate power at night rather than during the day based on the grid power usage prediction.

22. The power supply system according to claim 1, wherein the secondary battery includes a storage capacity (19) connected by a V2X (18).

23. The control unit Acquire an EV operation plan for operating an in-vehicle secondary battery (19) connected via the V2X and mounted on the vehicle as the storage capacity; 23. The power supply system according to claim 22, wherein the secondary battery and the on-board secondary battery are controlled by adding an SOC of the on-board secondary battery that is not scheduled to be operated based on the EV operation plan to an SOC of the stationary secondary battery.

24. 23. The power supply system according to claim 22, wherein the control unit acquires an EV operation plan for operating an on-board secondary battery (19) connected by the V2X and mounted on the vehicle as the power storage capacity, the power demand forecast excluding the on-board secondary battery, a load factor fluctuation forecast indicating fluctuations in the load factor of the fuel cell that will change over time, and a grid power usage forecast that predicts usage of external grid power (12), and creates a charging plan for the on-board secondary battery based on these.

25. The control unit obtaining a solar power surplus forecast of power that will be extra generated by the solar power generation device; 25. The power supply system according to claim 24, wherein, when charging of the vehicle-mounted secondary battery is required and use of the vehicle-mounted secondary battery is planned for the next day or later, a charging priority for the vehicle-mounted secondary battery is lowered, and a charging plan for the vehicle-mounted secondary battery is formulated so that the vehicle-mounted secondary battery is charged by surplus solar power generation based on the solar power generation surplus prediction or by power generation by the fuel cell.

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