Power conditioner and power storage system

Abstract

To provide a power conditioner which can be offgrid in more various conditions than before.SOLUTION: (1) If use schedule information stored in a storage unit 16 indicates that use of an electric vehicle 50 is not scheduled, a control unit 14 of a power conditioner 10 according to the present invention starts a power storage device 30 and an electric vehicle charging / discharging device 40 to transfer power in a power storage battery 31 to a power storage battery 51 on condition that a predetermined relationship is established between the sum of the available capacity of the power storage battery 31 and the available capacity of the power storage battery 51 and a surplus power amount. (2) If the use schedule information indicates that use of the electric vehicle 50 is scheduled, the control unit 14 starts the power storage device 30 and the electric vehicle charging / discharging device 40 to transfer the power in the power storage battery 31 to the power storage battery 51 on condition that a predetermined relationship is established between the available capacity of the power storage battery 31 and the surplus power amount.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power conditioner and a power storage system that are used by being connected to a commercial power grid, a solar power generation device, a power storage device, an electric vehicle charge / discharge device, and a load device. [Background technology]

[0002] Conventionally, there is known a system that determines how much to charge a storage battery mounted on an electric vehicle during the night based on a predicted value of the amount of power generated by a photovoltaic power generation device, a predicted value of the amount of power consumed by a load device, and the remaining capacity of the storage battery (see, for example, Patent Document 1). This system is configured to charge the storage battery mounted on the electric vehicle with power purchased from a commercial power grid when, for example, the predicted value of the amount of power generated is small and the predicted value of the amount of power consumed is large.

[0003] The part that realizes the transfer of power between the commercial power grid, the solar power generation device, the load device, and the charging / discharging device for electric vehicles for charging / discharging the storage battery installed in the electric vehicle is called a "power conditioner." The charging / discharging device for electric vehicles is also called "V2H (Vehicle to Home)." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7254481 Summary of the Invention [Problem to be solved by the invention]

[0005] In response to the recent increase in the electricity purchase price (the unit price applied when purchasing electricity from the commercial power grid) and the decrease in the electricity selling price (the unit price applied when selling electricity generated by solar power generation equipment), there is a growing need for an "off-grid" system in which generated electricity is used for self-consumption rather than sold, and no electricity is purchased at all. However, the above-mentioned conventional system was configured to purchase electricity when the predicted amount of electricity generated was small and the predicted amount of electricity consumed was large, and therefore did not adequately meet the needs of the off-grid system.

[0006] The present invention has been made in consideration of the above circumstances, and has an object to provide a power conditioner and a power storage system that can realize off-grid operation in more situations than ever before. [Means for solving the problem]

[0007] In order to solve the above problems, the power conditioner of the present invention is a power conditioner used by connecting to a commercial power system, a solar power generation device, a power storage device including a first storage battery, an electric vehicle charging / discharging device connected to an electric vehicle including a second storage battery, and a load device, and is provided with a power conversion unit located between the commercial power system and the electric vehicle charging / discharging device, a control unit that controls the power storage device, the electric vehicle charging / discharging device, and the power conversion unit, a prediction unit that predicts the amount of surplus power, which is the difference between the amount of power generated by the solar power generation device and the amount of power consumed by the load device on a control day, and a memory unit that stores planned use information regarding whether or not the electric vehicle is scheduled to be used on the control day, and the control unit is configured to operate the power storage device and the electric vehicle charging / discharging device under condition (1) or (2) below to transfer power from the first storage battery to the second storage battery. (1) When the usage schedule information indicates that no usage is scheduled, a condition is that the sum of the available capacity of the first storage battery and the available capacity of the second storage battery has a predetermined relationship with the amount of surplus electricity. (2) When the usage schedule information indicates that usage is scheduled, a condition is that the available capacity and the amount of surplus power of the first storage battery have a predetermined relationship.

[0008] In this configuration, the power of the first storage battery is transferred to the second storage battery on the condition that the sum of the free capacity of the first storage battery and the free capacity of the second storage battery has a predetermined relationship with the amount of surplus power, or the free capacity of the first storage battery has a predetermined relationship with the amount of surplus power. Therefore, with this configuration, it is possible to create free space in the first storage battery for the amount of surplus power, or to charge the second storage battery without purchasing power, and as a result, the amount of power purchased and sold can be reduced.

[0009] The control unit of the power conditioner may be configured, for example, as follows: when the usage schedule information indicates that no use is scheduled and the sum of the available capacity of the first storage battery and the available capacity of the second storage battery is less than the surplus power amount, (1-1) if the total capacity of the first storage battery is equal to or greater than the surplus power amount, operate the power storage device and the electric vehicle charging / discharging device to transfer power from the first storage battery to the second storage battery, and (1-2) if the total capacity of the first storage battery is less than the surplus power amount, operate the power storage device, the electric vehicle charging / discharging device, and the power conversion unit to discharge the first storage battery and the second storage battery to the load device.

[0010] The control unit of the power conditioner may be configured, for example, as follows: when the usage schedule information indicates that usage is scheduled, (2-1) if the available capacity of the first storage battery is equal to or greater than the surplus power amount, operate the electric vehicle charging / discharging device and the power conversion unit to charge the second storage battery with power from the commercial power system, and (2-2) if the available capacity of the first storage battery is less than the surplus power amount, operate the storage device and the electric vehicle charging / discharging device to transfer power from the first storage battery to the second storage battery.

[0011] Furthermore, in order to solve the above-mentioned problems, the energy storage system of the present invention is an energy storage system comprising a solar power generation device, an energy storage device including a first storage battery, an electric vehicle charging / discharging device connected to an electric vehicle including a second storage battery, and a power conditioner connected to these, wherein the power conditioner has a power conversion unit located between a commercial power system and the electric vehicle charging / discharging device and is connected to a load device for use, the energy storage system comprising: a control unit that controls the energy storage device, the electric vehicle charging / discharging device, and the power conversion unit; a prediction unit that predicts an amount of surplus power, which is the difference between the amount of power generated by the solar power generation device and the amount of power consumed by the load device on a control day; and a memory unit that stores planned use information regarding whether or not the electric vehicle is scheduled to be used on the control day, and the control unit operates the energy storage device and the electric vehicle charging / discharging device under the condition (1) or (2) below to transfer power from the first storage battery to the second storage battery. (1) When the usage schedule information indicates that no usage is scheduled, a condition is that the sum of the available capacity of the first storage battery and the available capacity of the second storage battery has a predetermined relationship with the amount of surplus electricity. (2) When the usage schedule information indicates that usage is scheduled, a condition is that the available capacity and the amount of surplus power of the first storage battery have a predetermined relationship.

[0012] The control unit, the prediction unit, and the storage unit of the power storage system may be included in, for example, a power conditioner. Effect of the Invention

[0013] According to the present invention, it is possible to provide a power conditioner and a power storage system that can realize off-grid operation in more situations than ever before. [Brief description of the drawings]

[0014] [Figure 1] 1 is a block diagram showing a power storage system including a power conditioner according to an embodiment of the present invention. [Diagram 2]FIG. 1A is a diagram showing the relationship between the total capacity, remaining capacity, and available capacity of storage batteries included in a power storage device, and FIG. 1B is a diagram showing the relationship between the total capacity, remaining capacity, and available capacity of storage batteries mounted on an electric vehicle. [Diagram 3] FIG. 4 is a flow diagram showing control executed by a control unit of the power conditioner according to the embodiment. [Figure 4] 4 is a flow diagram showing control executed by a control unit of the power conditioner according to the embodiment after the control shown in FIG. 3. [Diagram 5] 4 is a flow chart showing another control executed by a control unit of the power conditioner according to the embodiment after the control shown in FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, embodiments of a power conditioner and a power storage system according to the present invention will be described with reference to the accompanying drawings.

[0016] [Example] 1 shows a power storage system including a power conditioner 10 according to an embodiment of the present invention. As shown in the figure, the power conditioner 10 is used by being connected to a solar power generation device 20, a power storage device 30, an electric vehicle charging / discharging device 40, a commercial power system 60, and a household load 70, and includes a DC / DC conversion unit 11, a bidirectional DC / DC conversion unit 12, a bidirectional DC / AC conversion unit 13, a control unit 14, a prediction unit 15, and a storage unit 16.

[0017] The solar power generation device 20 includes a solar cell installed on the roof of a house or the like, and outputs DC power in an amount corresponding to the amount of solar radiation. In this specification, this amount of DC power will be referred to as the "amount of generated power."

[0018] The power storage device 30 includes a storage battery 31 having a total capacity of BS [kWh] (see FIG. 2(A)). The power storage device 30 can charge the storage battery 31 with DC power supplied from the bidirectional DC / DC conversion unit 12. The power storage device 30 can also discharge the storage battery 31 to supply DC power to the bidirectional DC / DC conversion unit 12. The storage battery 31 corresponds to the "first storage battery" of the present invention.

[0019] The electric vehicle charging / discharging device 40 includes a bidirectional DC / DC converter 41 and a cable 42. The electric vehicle charging / discharging device 40 is connected via the cable 42 to an electric vehicle 50 equipped with a storage battery 51 having a total capacity of BEV [kWh] (see FIG. 2(B)). The electric vehicle charging / discharging device 40 (bidirectional DC / DC converter 41) can charge the storage battery 51 with DC power supplied from the coordination point 17. The electric vehicle charging / discharging device 40 (bidirectional DC / DC converter 41) can also discharge the storage battery 51 to supply DC power to the coordination point 17. The storage battery 51 corresponds to the "second storage battery" of the present invention.

[0020] The electric vehicle 50 is an electric vehicle (EV) or a plug-in hybrid vehicle (PHV).

[0021] The household load 70 is a refrigerator, a television, or the like that consumes AC power supplied from at least one of the commercial power system 60 and the bidirectional DC / AC converter 13. In this specification, the amount of power consumed by the household load 70 is referred to as the "power consumption amount."

[0022] The DC / DC converter 11 can boost the DC power output by the solar power generation device 20 and supply the boosted DC power to the connection point 17 .

[0023] The bidirectional DC / DC converter 12 can step down the DC power supplied from the connection point 17 and supply the stepped-down DC power to the power storage device 30. The bidirectional DC / DC converter 12 can also step up the DC power supplied from the power storage device 30 and supply the stepped-up DC power to the connection point 17.

[0024] The bidirectional DC / AC conversion unit 13 includes a DC side input / output terminal connected to the coordination point 17, and an AC side input / output terminal connected to the commercial power system 60 and the household load 70. The bidirectional DC / AC conversion unit 13 can convert DC power supplied to the DC side input / output terminal into AC power and output it from the AC side input / output terminal. The bidirectional DC / AC conversion unit 13 can also convert AC power supplied to the AC side input / output terminal into DC power and output it from the DC side input / output terminal. The bidirectional DC / AC conversion unit 13 corresponds to the "power conversion unit" of the present invention.

[0025] 1 may be present between the bidirectional DC / AC conversion unit 13 and the commercial power grid 60, and between the bidirectional DC / AC conversion unit 13 and the household load 70. The same applies to between the coordination point 17 and each unit (DC / DC conversion unit 11, bidirectional DC / DC conversion unit 12, bidirectional DC / AC conversion unit 13, and electric vehicle charging / discharging device 40).

[0026] The control unit 14 controls the operations of the power storage device 30, the electric vehicle charging / discharging device 40, the bidirectional DC / DC conversion unit 12, and the bidirectional DC / AC conversion unit 13. This will be described in detail later.

[0027] The prediction unit 15 uses a trained model created in advance by machine learning using teacher data such as past weather conditions, past power generation amounts, and past power consumption amounts to predict the amount of power generation PG [kWh] from 1:00 a.m. on the control day to 12:59 a.m. the next day, the amount of power consumption PC [kWh] during the time period when power is generated on the control day (e.g., from 7:00 a.m. to 5:00 p.m.), and the amount of power consumption PC′ [kWh] during the time period when power is generated and the time period when power is not generated on the control day (e.g., from 5:00 p.m. to 12:59 a.m. the next day) (i.e., from 7:00 a.m. on the control day to 12:59 a.m. the next day) based on the weather conditions (weather forecast) on the day when the control unit 14 should perform control. The prediction unit 15 makes this prediction at 12:30 a.m. on the control day.

[0028] The storage unit 16 stores planned use information on whether or not the electric vehicle 50 is scheduled to be used on a daily basis. The planned use information includes at least whether or not the electric vehicle 50 is scheduled to be used on the control day. The user can store new planned use information in the storage unit 16 or change the stored planned use information via an appropriate user interface device. The user needs to store in the storage unit 16 whether or not the electric vehicle 50 will be used on the control day by 12:30 a.m. on the control day, that is, before the prediction by the prediction unit 15 starts.

[0029] The storage unit 16 also stores a set upper limit value related to charging the storage battery 51. This will be described in detail later.

[0030] Next, the control (control flows F1, F2, F3) by the control unit 14 will be described in detail with reference to Figures 3 to 5. The control unit 14 sequentially executes each step of the control flows F1, F2, F3 immediately after the prediction unit 15 completes prediction of the generated power amount PG and the consumed power amounts PC, PC', that is, just after 12:30 a.m. on the control day.

[0031] In step S1-1 of the control flow F1, the control unit 14 calculates the surplus energy PE [kWh] and the shortage energy PI [kWh]. The surplus energy PE can be calculated using the formula "power generation PG - power consumption PC". The shortage energy PI [kWh] can be calculated using the formula "power consumption PC' - power generation PG".

[0032] As described above, the generated power amount PG and the consumed power amounts PC and PC' are predicted values. Therefore, it can be said that the control unit 14 predicts the surplus power amount PE and the shortage power amount PI in step S1-1.

[0033] In step S1-2, the control unit 14 acquires the remaining capacity BS1 [kWh] of the storage battery 31 included in the power storage device 30 (hereinafter referred to as "remaining battery capacity") and the remaining capacity BEV1 of the storage battery 51 mounted on the electric vehicle 50 (hereinafter referred to as "remaining EV capacity") (see FIG. 2). The control unit 14 can acquire the value of the remaining battery capacity BS1 via a BMS (Battery Management System) associated with the storage battery 31. The control unit 14 can also acquire the value of the remaining EV capacity BEV1 via the BMS associated with the storage battery 51.

[0034] In step S1-3, the control unit 14 calculates the free capacity BS2 [kWh] of the storage battery 31 included in the power storage device 30 (hereinafter referred to as "free battery capacity") and the free capacity BEV2 of the storage battery 51 mounted on the electric vehicle 50 (hereinafter referred to as "free EV capacity") (see FIG. 2). The free battery capacity BS2 can be calculated using the formula "total capacity BS - remaining battery capacity BS1". Also, the free EV capacity BEV2 can be calculated using the formula "total capacity BEV - remaining EV capacity BEV1".

[0035] In step S1-4, the control unit 14 determines whether or not there is a plan to use the electric vehicle 50 on the control day, by referring to the usage plan information stored in the memory unit 16. If there is no plan to use the electric vehicle 50, the control unit 14 proceeds to control flow F2, and if there is a plan to use the electric vehicle 50, the control unit 14 proceeds to control flow F3.

[0036] In step S2-1 of control flow F2, which is executed when the usage plan information indicates that there is no plan for use (i.e., when electric vehicle 50 is connected to electric vehicle charging / discharging device 40 during the day on the control day and storage battery 51 can be used as a power supply source for household load 70), control unit 14 determines whether or not the surplus energy PE predicted in step S1-1 is equal to or greater than 0. If the surplus energy PE is equal to or greater than 0, the process proceeds to step S2-2, and if not, the process proceeds to step S2-6.

[0037] In step S2-2, the control unit 14 judges whether the sum of the storage battery free capacity BS2 and the EV free capacity BEV2 is equal to or greater than the surplus energy amount PE. The sum of the storage battery free capacity BS2 and the EV free capacity BEV2 being equal to or greater than the surplus energy amount PE means that the storage batteries 31, 51 already have a free capacity that is sufficient to store all of the surplus energy expected to occur on the control day. For this reason, if the sum of the storage battery free capacity BS2 and the EV free capacity BEV2 is equal to or greater than the surplus energy amount PE, the control unit 14 ends the control flow F2 without doing anything. On the other hand, the sum of the storage battery free capacity BS2 and the EV free capacity BEV2 being less than the surplus energy amount PE means that the storage batteries 31, 51 do not have a free capacity that is sufficient to store all of the surplus energy expected to occur on the control day. The surplus energy that could not be stored in the storage batteries 31, 51 is sold at a low unit price. Therefore, when the sum of the storage battery free space BS2 and the EV free space BEV2 is less than the surplus power amount PE, the control unit 14 proceeds to step S2-3 to avoid undesirable power sale.

[0038] In step S2-3, the control unit 14 determines whether the total capacity BS of the storage battery 31 is equal to or greater than the surplus energy PE. The total capacity BS being equal to or greater than the surplus energy PE means that there is a possibility that all of the surplus power can be stored by the storage battery 31 alone. Therefore, if the total capacity BS is equal to or greater than the surplus energy PE, the control unit 14 proceeds to step S2-4 to increase the storage battery free capacity BS2. On the other hand, if not, the control unit 14 proceeds to step S2-5 to increase the storage battery free capacity BS2 and the EV free capacity BEV2.

[0039] In step S2-4, the control unit 14 operates the power storage device 30, the electric vehicle charging / discharging device 40, and the bidirectional DC / DC conversion unit 12 to transfer the power of the storage battery 31 to the storage battery 51 via the connection point 17. In this specification, this transfer is referred to as "EleMove." EleMove is a registered trademark owned by the applicant. EleMove ends when the EV free capacity BEV2 becomes 0. At this time, the remaining battery capacity BS1 has not yet become 0.

[0040] After the EleMove operation is completed, the control unit 14 operates the power storage device 30, the bidirectional DC / DC conversion unit 12, and the bidirectional DC / AC conversion unit 13 to discharge the storage battery 31 to the household load 70 so that the available battery capacity BS2 matches the surplus power amount PE. If the power consumption of the household load 70 is low and the available battery capacity BS2 does not match the surplus power amount PE even after this discharge, a small amount of power is sold during the day on the control day.

[0041] In step S2-5, control unit 14 operates power storage device 30, electric vehicle charging / discharging device 40, bidirectional DC / DC converter 12 and bidirectional DC / AC converter 13 to discharge batteries 31, 51 to household load 70 so that the sum of battery free capacity BS2 and EV free capacity BEV2 matches the surplus energy PE. If the power consumption of household load 70 is low and this discharge does not cause the sum of battery free capacity BS2 and EV free capacity BEV2 to match the surplus energy PE, electricity will be sold during the day on the control day.

[0042] In step S2-6, which is executed when it is determined that the surplus energy PE is less than 0, the control unit 14 determines whether or not the sum of the battery remaining capacity BS1 and the EV remaining capacity BEV1 is equal to or greater than the energy shortage PI. The sum of the battery remaining capacity BS1 and the EV remaining capacity BEV1 being equal to or greater than the energy shortage PI means that the power shortage occurring on the control day can be compensated for by the power already stored in the storage batteries 31, 51. For this reason, if the sum of the battery remaining capacity BS1 and the EV remaining capacity BEV1 is equal to or greater than the energy shortage PI, the control unit 14 ends the control flow F2 without doing anything. On the other hand, if the sum of the battery remaining capacity BS1 and the EV remaining capacity BEV1 is less than the energy shortage PI, it means that power purchase will have to be performed at a high unit price during the day of the control day if things continue as they are. For this reason, if the sum of the battery remaining capacity BS1 and the EV remaining capacity BEV1 is less than the energy shortage PI, the control unit 14 proceeds to step S2-7 to avoid undesirable power purchase.

[0043] In step S2-7, the control unit 14 operates the power storage device 30, the electric vehicle charging / discharging device 40, the bidirectional DC / DC converter 12, and the bidirectional DC / AC converter 13 to charge the storage batteries 31, 51 with power supplied from the commercial power grid 60 until the sum of the storage battery remaining capacity BS1 and the EV remaining capacity BEV1 matches the power shortage amount PI. As described above, the control unit 14 executes step S2-7 just after 12:30 a.m. on the control day. Also, the unit price of power purchased late at night is lower than the unit price of power purchased during the day. Therefore, according to step S2-7, it is possible to reduce the electricity bill burden on the user compared to the case where power is purchased during the day.

[0044] In step S3-1 of control flow F3, which is executed when the usage plan information indicates that usage is planned (i.e., when electric vehicle 50 is not connected to electric vehicle charging / discharging device 40 during the day on the control day and storage battery 51 cannot be used as a power supply source for household load 70), control unit 14 determines whether or not surplus energy PE is equal to or greater than 0. If surplus energy PE is equal to or greater than 0, the process proceeds to step S3-2, and if not, the process proceeds to step S3-5.

[0045] In step S3-2, the control unit 14 determines whether the storage battery free capacity BS2 is equal to or greater than the surplus power amount PE. When the storage battery free capacity BS2 is equal to or greater than the surplus power amount PE, this means that the storage battery 31 already has a free capacity sufficient to store all of the surplus power expected to be generated on the control day. For this reason, when the storage battery free capacity BS2 is equal to or greater than the surplus power amount PE, the control unit 14 proceeds to step S3-3 to charge the storage battery 51 of the electric vehicle 50 in preparation for use of the electric vehicle 50. On the other hand, when the storage battery free capacity BS2 is less than the surplus power amount PE, this means that the storage battery 31 does not have a free capacity sufficient to store all of the surplus power expected to be generated on the control day. The surplus power that could not be stored in the storage battery 31 is sold at a low unit price. Therefore, when the available battery capacity BS2 is less than the surplus power amount PE, the control unit 14 proceeds to step S3-4 to avoid undesirable power sale and to charge the storage battery 51 of the electric vehicle 50 in preparation for use of the electric vehicle 50.

[0046] In step S3-3, control unit 14 operates electric vehicle charging / discharging device 40 and bidirectional DC / AC conversion unit 13 to charge storage battery 51 with power supplied from commercial power system 60 until EV remaining capacity BEV1 matches the set upper limit value stored in memory unit 16. The set upper limit value may be stored in memory unit 16 from the beginning, or may be stored together with the planned use information when the user stores the planned use information in memory unit 16. In the latter case, it is preferable that the user can arbitrarily set the set upper limit value within a range of, for example, total capacity BEV×0.5 to total capacity BEV×0.95.

[0047] In step S3-4, control unit 14 operates power storage device 30, electric vehicle charging / discharging device 40, and bidirectional DC / DC converter 12 to ele-move power from storage battery 31 to storage battery 51, aiming for battery free capacity BS2 to match surplus power amount PE. The ele-move ends when battery remaining capacity BS1 becomes 0 or EV free capacity BEV2 becomes 0. If the ele-move does not cause battery free capacity BS2 to match surplus power amount PE, control unit 14 discharges battery 31 toward household load 70, as in step S2-4, aiming for battery free capacity BS2 to match surplus power amount PE.

[0048] In addition, together with or after the Elemove, the control unit 14 charges the storage battery 51 with power supplied from the commercial power grid 60 until the EV remaining capacity BEV1 matches the set upper limit value stored in the memory unit 16, in the same manner as in step S3-3.

[0049] In step S3-5, which is executed when it is determined that the surplus energy amount PE is less than 0, the control unit 14 determines whether or not the storage battery remaining capacity BS1 is equal to or greater than the energy shortage amount PI. The storage battery remaining capacity BS1 being equal to or greater than the energy shortage amount PI means that the power shortage occurring on the control day can be compensated for by the power already stored in the storage battery 31. For this reason, when the storage battery remaining capacity BS1 is equal to or greater than the energy shortage amount PI, the control unit 14 proceeds to step S3-6 to charge the storage battery 51 of the electric vehicle 50 in preparation for use of the electric vehicle 50. On the other hand, when the storage battery remaining capacity BS1 is less than the energy shortage amount PI, it means that if things continue as they are, power purchase will have to be made at a high unit price during the day of the control day. For this reason, when the storage battery remaining capacity BS1 is less than the energy shortage amount PI, the control unit 14 proceeds to step S3-7 to avoid undesirable power purchases and to charge the storage battery 51 of the electric vehicle 50 in preparation for use of the electric vehicle 50.

[0050] In step S3-6, the control unit 14 charges the storage battery 51 with power supplied from the commercial power system 60 until the EV remaining capacity BEV1 matches the set upper limit value stored in the storage unit 16, in the same manner as in step S3-3.

[0051] In step S3-7, control unit 14 operates power storage device 30, bidirectional DC / DC converter 12, and bidirectional DC / AC converter 13 to charge storage battery 31 with power supplied from commercial power grid 60 until remaining battery capacity BS1 matches the amount of power shortage PI. In parallel with this, control unit 14 charges storage battery 51 with power supplied from commercial power grid 60 until remaining EV capacity BEV1 matches the set upper limit stored in memory unit 16, similar to step S3-3.

[0052] In this way, in the power conditioner 10 and the power storage system according to the present embodiment, the power of the storage battery 31 is transferred to the storage battery 51 during the night on the condition that the sum of the storage battery free capacity BS2 and the EV free capacity BEV2 has a predetermined relationship with the surplus power amount PE, or the storage battery free capacity BS2 and the surplus power amount PE have a predetermined relationship. Therefore, according to this configuration, it is possible to create a free space of the surplus power amount PE in the storage battery 31, or to charge the storage battery 51 without purchasing power, and as a result, the amount of power purchased and sold can be reduced. As a result, even if there are several rainy days in a row when power generation is not expected, it is possible to cover the power consumption of the household load 70 with the discharged power from the storage battery 31 and the storage battery 51 without purchasing power.

[0053] Although the embodiments of the power conditioner and the power storage system according to the present invention have been described above, the configurations of the present invention are not limited to these.

[0054] [Variations] For example, in FIG. 1, the control unit 14, the prediction unit 15, and the memory unit 16 are depicted as components of the power conditioner 10, but all or some of these may be located outside the power conditioner 10.

[0055] In addition, in FIG. 1, the DC / DC conversion unit 11 and the bidirectional DC / DC conversion unit 12 are depicted as if they were contained in the same housing as components of the power conditioner 10, but all or part of these may be contained in separate housings.

[0056] The prediction unit 15 may predict the generated power amount PG and the consumed power amount PC using a method other than the method using the learned model. For example, the prediction unit 15 may predict the generated power amount PG and the consumed power amount PC by averaging the past generated power amounts and the past consumed power amounts.

[0057] Moreover, "12:30 AM on the control day" when the prediction unit 15 makes the prediction and "after 12:30 AM on the control day" when the control unit 14 executes each step of the control flows F1, F2, and F3 are merely examples. In the present invention, it is preferable to perform the prediction and the subsequent execution of the control flows F1, F2, and F3 between 11:00 PM on the day before the control day and 3:00 AM on the control day, when the amount of power consumption of the household load 70 is relatively small and there is ample time until the start of use of the electric vehicle 50.

[0058] Furthermore, the connection between electric vehicle charging / discharging device 40 and electric vehicle 50 does not have to be a physical connection via cable 42, but may be a non-contact connection. [Explanation of symbols]

[0059] 10 Power conditioner 11 DC / DC conversion section 12 Bidirectional DC / DC conversion section 13 Bidirectional DC / AC conversion section 14 Control section 15 Prediction Department 16 Memory section 17 Linkage points 20. Solar power generation equipment 30 Energy storage device 31 Storage battery (first storage battery) 40 Charging and discharging equipment for electric vehicles 41 Bidirectional DC / DC conversion section 42 Cable 50 Electric Vehicles 51 Battery (Second Battery) 60 Commercial Power Systems 70 Household Load

Claims

1. A power conditioner used by connecting to a commercial power grid, a solar power generation device, a power storage device including a first storage battery, an electric vehicle charge / discharge device connected to an electric vehicle including a second storage battery, and a load device, a power conversion unit located between the commercial power system and the electric vehicle charging / discharging device; a control unit that controls the power storage device, the electric vehicle charging / discharging device, and the power conversion unit; a prediction unit that predicts an amount of surplus power, which is a difference between an amount of power generated by the photovoltaic power generation device and an amount of power consumed by the load device on a control day; a storage unit that stores usage plan information regarding whether or not the electric vehicle is scheduled to be used on the control day; and Equipped with The control unit operates the power storage device and the electric vehicle charging / discharging device under the following condition (1) or (2), to transfer electric power of the first storage battery to the second storage battery: The power conditioner is characterized by the above. (1) When the usage schedule information indicates that there is no usage schedule, the condition is that the sum of the free capacity of the first storage battery and the free capacity of the second storage battery has a predetermined relationship with the amount of surplus electricity. (2) When the use schedule information indicates that the use is scheduled, a condition is that the available capacity of the first storage battery and the amount of surplus power have a predetermined relationship.

2. When the use schedule information indicates that the use schedule is not scheduled, and the sum of the available capacity of the first storage battery and the available capacity of the second storage battery is less than the surplus power amount, (1-1) when the total capacity of the first storage battery is equal to or greater than the surplus power amount, operate the power storage device and the electric vehicle charging / discharging device to transfer power from the first storage battery to the second storage battery; (1-2) When the total capacity of the first storage battery is less than the surplus power amount, the power storage device, the electric vehicle charging / discharging device, and the power conversion unit are operated to drive the load device with the power of the first storage battery and the second storage battery. The power conditioner according to claim 1 .

3. When the use schedule information indicates that the use is scheduled, the control unit: (2-1) when the free capacity of the first storage battery is equal to or greater than the surplus power amount, operate the electric vehicle charging / discharging device and the power conversion unit to charge the first storage battery with power from the commercial power system; (2-2) When the free capacity of the first storage battery is less than the surplus power amount, the storage device and the electric vehicle charging / discharging device are operated to transfer the power of the first storage battery to the second storage battery. The power conditioner according to claim 1 or 2.

4. A power storage system including a solar power generation device, a power storage device including a first storage battery, an electric vehicle charging / discharging device connected to an electric vehicle including a second storage battery, and a power conditioner connected to these devices, the power conditioner having a power conversion unit located between a commercial power system and the electric vehicle charging / discharging device, and connected to a load device for use, a control unit that controls the power storage device, the electric vehicle charging / discharging device, and the power conversion unit; a prediction unit that predicts an amount of surplus power, which is a difference between an amount of power generated by the photovoltaic power generation device and an amount of power consumed by the load device on a control day; a storage unit that stores usage plan information regarding whether or not the electric vehicle is scheduled to be used on the control day; and Equipped with The control unit operates the power storage device and the electric vehicle charging / discharging device under the following condition (1) or (2), to transfer electric power of the first storage battery to the second storage battery: The present invention relates to an energy storage system. (1) When the usage schedule information indicates that there is no usage schedule, the condition is that the sum of the free capacity of the first storage battery and the free capacity of the second storage battery has a predetermined relationship with the amount of surplus electricity. (2) When the use schedule information indicates that the use is scheduled, a condition is that the available capacity of the first storage battery and the amount of surplus power have a predetermined relationship.

5. The control unit, the prediction unit, and the storage unit are included in the power conditioner. The power storage system according to claim 4 .

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