Electric power control device

Abstract

To provide an electric power control unit capable of properly charging a battery while suppressing battery degradation.SOLUTION: The electric power control device is configured to predict the electricity consumption and generation balance for a specified period as the predicted electricity supply and demand balance X based on the amount of electricity generated by the power generation system, the predicted electricity consumption during the day based on the load demand, and the predicted amount of electricity required for cooling the battery, and when the difference between the total energy that is calculated by adding the predicted energy balance X and the remaining battery capacity F and the battery degradation prevention threshold Y is greater than the lower limit threshold SOCth of the battery, discharge an amount of power equivalent to the difference between the remaining battery capacity and the power threshold for preventing battery degradation.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a power control device. [Background technology]

[0002] The power control system described in Patent Document 1 below controls the supply of power to a house equipped with solar panels and a stationary storage battery. The power control system predicts the amount of power consumed by the house, predicts the amount of power generated by the solar panel, and predicts the amount of surplus and shortage of power due to the power generated by the solar panel. The power control system determines the amount of charge to the stationary storage battery and the on-board battery based on the results of these predictions and the predicted driving schedule of an electric vehicle equipped with an on-board battery. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-78144 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the charge amount is determined regardless of the charge state of the stationary storage battery and the vehicle battery, so in some cases the battery may be charged beyond the appropriate charge amount. When a storage battery is charged beyond the appropriate charge amount, it enters a so-called high SOC state, which accelerates the deterioration of the storage battery.

[0005] The present disclosure aims to appropriately charge a storage battery while suppressing deterioration of the storage battery. [Means for solving the problem]

[0006] The present disclosure relates to a power control device that predicts the power balance for a specified period as a predicted power balance based on the amount of power generated by a power generation device, the amount of power consumption predicted from the daytime power consumption of a load, and the amount of cooling power predicted to be required to cool a storage battery, and if the difference between the total amount of power obtained by adding the predicted power balance and the remaining power amount of the storage battery and the deterioration prevention power threshold of the storage battery is greater than the lower power threshold of the storage battery, discharges power equivalent to the difference between the remaining power amount of the storage battery and the deterioration prevention power threshold. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to appropriately charge a storage battery while suppressing deterioration of the storage battery. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of a power supply system including a power control device according to this embodiment. [Figure 2] FIG. 2 is a flowchart illustrating the operation of the power control device shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components in the drawings will be denoted by the same reference numerals as much as possible, and duplicated descriptions will be omitted.

[0010] The power supply system 2 will be described with reference to Fig. 1. The power supply system 2 is a system that supplies power to, for example, a facility. The power supply system 2 includes a power control device 21, an equipment monitoring device 22, a power usage prediction unit 23, a power generation prediction unit 24, a power generation device 25, a storage battery 26, a battery cooling device 27, a load 28, and grid power 29.

[0011] In this embodiment, the power control device 21, the facility monitoring device 22, the power usage prediction unit 23, the generated power prediction unit 24, the power generation device 25, the storage battery 26, the battery cooling device 27, and the load 28 are installed in a facility to which power is supplied by the power supply system 2. The grid power 29 is a grid power network that supplies power to the facility to which the power supply system 2 supplies power.

[0012] The power usage prediction unit 23 is provided, for example, in a server provided in a location different from the facility. The generated power amount prediction unit 24 is provided, for example, in a server provided in a location different from the facility. The power usage prediction unit 23 and the generated power amount prediction unit 24 may be provided in the same server, or may be provided in different servers. The power usage prediction unit 23 and the generated power amount prediction unit 24 may be provided within the facility.

[0013] In this embodiment, the power generation device 25 is, for example, a solar cell panel. A solar cell panel is a device that generates electricity by converting sunlight into electricity using a solar cell. The solar cell panel is a device that can supply electricity only during times when it can receive sunlight. The DC power generated by the solar cell panel is converted into AC power by a power conditioner (not shown) and used. Note that the power generation device 25 can also be a power generation means other than a solar cell panel, such as wind power generation or geothermal power generation, as long as it is a power supply source different from the grid power 29.

[0014] The storage battery 26 is connected to a power conditioner (not shown) to control charging and discharging. For example, the storage battery 26 is charged with low-priced electricity such as late-night electricity supplied from the grid power 29 or electricity generated by the power generation device 25.

[0015] Battery cooling device 27 is a device for cooling storage battery 26. Battery cooling device 27 circulates, for example, cooling water or cooling oil, cools storage battery 26 by exchanging heat with it, and dissipates the heat in a heat exchanger. The structure of battery cooling device 27 is not particularly limited as long as it can cool storage battery 26. Power supplied to a pump for circulating the cooling water or cooling oil in battery cooling device 27 is supplied from storage battery 26, for example.

[0016] The load 28 includes, for example, an air conditioner or other air conditioning device, a water heater, a lighting device such as a light stand or ceiling light, and a home appliance such as a refrigerator or television.

[0017] The equipment monitoring device 22 is a device that monitors equipment such as the storage battery 26 and the battery cooling device. The equipment monitoring device 22 measures and monitors the remaining capacity of the storage battery 26, and transmits the remaining capacity data of the storage battery 26 to the power control device 21. The equipment monitoring device 22 measures and monitors the operating status of the battery cooling device 27, and transmits the power data required for the operation of the battery cooling device 27 to the power control device 21.

[0018] The power usage prediction unit 23 is a part that predicts the hourly power consumption of the load 28. The power usage prediction unit 23 can predict the hourly power consumption of the facility for the next day on the previous day. The power usage prediction unit 23 predicts the hourly power consumption of the air conditioning load and the hot water supply load, which are easily affected by weather conditions such as temperature, based on weather forecast data. The power usage prediction unit 23 predicts the hourly power consumption of other loads, which are less affected by weather conditions such as temperature, based on past history data, and adds these up to predict the hourly power consumption of the facility.

[0019] When predicting the hourly power consumption of the air conditioning load and the hot water supply load, the power consumption prediction unit 23 refers to the following day's weather forecast data, such as temperature, stored in the weather forecast database. When predicting the hourly power consumption of other loads, the power consumption prediction unit 23 refers to past history data stored by category in the power consumption history database. The power consumption prediction unit 23 sums up this data to predict the hourly power consumption of the facility.

[0020] The power generation amount prediction unit 24 predicts the amount of power generated by the power generation device 25 for each hour. The power generation amount prediction unit 24 can predict the amount of power generated by the facility for each hour for the next day on the previous day. For example, if the power generation device 25 is a solar panel, the power generation amount prediction unit 24 refers to weather forecast data for the next day, such as the amount of solar radiation, stored in a weather forecast database (not shown), and predicts the amount of power generated by the facility for each hour.

[0021] The power control device 21 is a device that adjusts the power supplied from the power generation device 25, the storage battery 26, and the grid power 29, and supplies the power to the load 28. The power control device 21 controls the charging and discharging of the storage battery 26. When the power generated by the power generation device 25 becomes surplus, the power control device 21 sells the surplus power to the grid power 29.

[0022] The power control device 21 receives remaining battery charge data of the storage battery 26 and power data required for the operation of the battery cooling device 27, transmitted from the equipment monitoring device 22. The power control device 21 receives a predicted value of the amount of power consumption transmitted from the power usage prediction unit 23. The power control device 21 receives a predicted value of the amount of power generation transmitted from the power generation amount prediction unit 24.

[0023] The power control device 21 has, as electrical components, a microcomputer, a wireless circuit, a data transfer circuit, and a power supply circuit. The microcomputer has a CPU, a ROM, a RAM, and a flash memory. The flash memory includes a secure area in which information cannot be read from outside the power control device 21. The microcomputer executes various control programs stored in a non-transitory physical storage medium to perform various processes and control the operation of the power control device 21. The wireless circuit controls data communication with external devices via a communication network. The data transfer circuit controls data communication with the equipment monitoring device 22.

[0024] The power control device 21 has, as functional components, a power balance prediction unit 211 and a battery control unit 212. The power balance prediction unit 211 is a part that predicts the power balance for a predetermined period as a predicted power balance X from the amount of power generated by the power generation device 25, the amount of power usage predicted from the daytime power usage of the load 28, and the amount of cooling power predicted to be required to cool the storage battery 26.

[0025] The battery control unit 212 is a part that discharges power equivalent to the difference between the remaining power F of the storage battery 26 and the deterioration prevention power threshold Y when the difference between the total power obtained by adding the predicted power balance X and the remaining power F of the storage battery 26 and the deterioration prevention power threshold Y of the storage battery 26 is greater than the lower power threshold SOCth of the storage battery 26.

[0026] Next, the operation of the power control device 21 will be described with reference to Fig. 2. In step S01, the power balance prediction unit 211 calculates the amount of power required for equipment operation. The power balance prediction unit 211 calculates the amount of power required for operation of the battery cooling device 27 based on, for example, power data required for operation of the battery cooling device 27 transmitted from the equipment monitoring device 22.

[0027] In step S02, the power balance prediction unit 211 acquires a predicted value of the amount of power generated by the power generation device 25. The predicted value of the amount of power generated by the power generation device 25 is included in, for example, prediction data transmitted from the power generation amount prediction unit 24. In the description with reference to Fig. 2, the prediction data includes the amount of power generated by the facility for each hour on the next day.

[0028] In step S03, the power balance prediction unit 211 acquires a predicted value of the power consumption of the load 28. The predicted value of the power consumption of the load 28 is included, for example, in prediction data transmitted from the power usage prediction unit 23. In the description given with reference to FIG. 2, the prediction data includes the hourly power consumption of the facility for the next day.

[0029] The processes in steps S01 to S03 do not necessarily have to be performed in order, but may be performed in parallel or with a time lag.

[0030] In step S04 following the processing of steps S01 to S03, the power balance prediction unit 211 predicts the predicted power balance X of the facility. In the explanation given with reference to Fig. 2, the predicted power balance X is calculated by subtracting the predicted value of the amount of power consumed in the facility on the next day and the predicted value of the amount of power required for operation of the battery cooling device 27 on the next day from the predicted value of the amount of power generated in the facility on the next day.

[0031] Steps S11 and S21 are executed in parallel with steps S01 to S04. In step S11, the power balance prediction unit 211 calculates the remaining energy F of the storage battery 26. The remaining energy F of the storage battery 26 is included in the remaining capacity data of the storage battery 26 transmitted from the equipment monitoring device 22.

[0032] In step S21, the power balance prediction unit 211 calculates a deterioration prevention power threshold Y of the storage battery 26. The deterioration prevention power threshold Y is a threshold of the SOC that accelerates deterioration of the storage battery 26 if the storage battery 26 is charged in excess of Y.

[0033] When the processing of steps S04, S11, and S21 is completed, the process proceeds to step S05. In step S05, the battery control unit 212 determines whether the difference between the total amount of power obtained by adding the predicted power balance X and the remaining power amount F of the storage battery 26 and the deterioration prevention power threshold Y of the storage battery 26 is greater than the lower limit power threshold SOCth of the storage battery 26. The lower limit power threshold SOCth is a predetermined SOC that must be ensured.

[0034] If the difference between the total amount of power obtained by adding the predicted power balance X and the remaining energy F of the storage battery 26 and the deterioration prevention power threshold Y of the storage battery 26 is greater than the lower limit power threshold SOCth of the storage battery 26 (step S05: YES), the process proceeds to step S06. If the difference between the total amount of power obtained by adding the predicted power balance X and the remaining energy F of the storage battery 26 and the deterioration prevention power threshold Y of the storage battery 26 is not greater than the lower limit power threshold SOCth of the storage battery 26 (step S05: NO), the process proceeds to step S07.

[0035] In step S06, the battery control unit 212 determines that there is no need to charge the storage battery 26 overnight. If the remaining energy F of the storage battery 26 is greater than the deterioration prevention power threshold Y of the storage battery 26, the battery control unit 212 discharges the difference between the remaining energy F and the power corresponding to the deterioration prevention power threshold Y.

[0036] In step S07, battery control unit 212 charges storage battery 26 to an amount of power equivalent to the predicted value of the power consumption of load 28. If the predicted value of the power consumption of load 28 is greater than deterioration prevention power threshold Y, battery control unit 212 charges storage battery 26 to an amount of power equivalent to deterioration prevention power threshold Y.

[0037] In step S05, the charge / discharge conditions are determined for the storage battery 26 installed in the facility, but if an electric vehicle is connected to the facility, the charge / discharge conditions may also be determined for the battery of the electric vehicle. For example, the running time of the electric vehicle may be predicted, and the surplus power of the battery may be calculated and included in the determination of the charge / discharge conditions for the storage battery 26.

[0038] The power control device 21 according to this embodiment controls the exchange of power among the storage battery 26, the power generation device 25, and the load 28. The power control device 21 includes a power balance prediction unit 211 and a battery control unit 212. The power balance prediction unit 211 predicts the power balance for a predetermined period as a predicted power balance X based on the amount of power generated by the power generation device 25, the amount of power usage predicted from the daytime power usage of the load 28, and the amount of cooling power predicted to be required to cool the storage battery 26. When the difference between the combined amount of power obtained by adding the predicted power balance X and the remaining power F of the storage battery 26 and the deterioration prevention power threshold Y of the storage battery 26 is greater than the lower limit power threshold SOCth of the storage battery 26, the battery control unit 212 discharges power equivalent to the difference between the remaining power F of the storage battery 26 and the deterioration prevention power threshold Y.

[0039] According to this embodiment, the power balance for a predetermined period is predicted as the predicted power balance X from the amount of power generated by the power generation device 25, the amount of power usage predicted from the daytime power usage of the load 28, and the amount of cooling power predicted to be required to cool the storage battery 26. Therefore, the predicted power balance X can be predicted taking into account not only the load 28 but also the power required to cool the storage battery 26. Since surplus power equivalent to the difference between the remaining power amount F of the storage battery 26 and the degradation prevention power threshold Y is discharged, it is possible to avoid maintaining the storage battery 26 in a high SOC state and suppress degradation of the storage battery 26.

[0040] The control unit (ECU) and methods described herein may be implemented by a special-purpose computer configured by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control unit (ECU) and methods described herein may be implemented by a special-purpose computer configured by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit (ECU) and methods described herein may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory storage medium.

[0041] The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Design modifications to these specific examples made by a person skilled in the art as appropriate are also included within the scope of the present disclosure as long as they comprise the features of the present disclosure. The elements of the above-described specific examples, as well as their arrangement, conditions, shape, etc., are not limited to those exemplified and can be modified as appropriate. The elements of the above-described specific examples can be combined in various ways as appropriate, as long as no technical contradictions arise. [Explanation of symbols]

[0042] 2: Power supply system 21: Power control device 211: Power balance forecasting unit 212: Battery control unit 22: Equipment monitoring device 23: Power consumption prediction unit 24: Power generation prediction unit 25: Power generation equipment 26: Storage battery 27:Battery cooling device 28: Load 29: System Power

Claims

[Claim 1] A power control device that controls power exchange between a storage battery, a power generation device, and a load, predicting a power balance for a predetermined period as a predicted power balance from the amount of power generated by the power generation device, the amount of power usage predicted from the daytime power usage of the load, and the amount of cooling power predicted to be required to cool the storage battery; When the difference between the total amount of power obtained by adding the predicted power balance and the remaining amount of power of the storage battery and the deterioration prevention power threshold of the storage battery is greater than the lower limit power threshold of the storage battery, the power control device discharges power equivalent to the difference between the remaining amount of power of the storage battery and the deterioration prevention power threshold.

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