Power conditioner and power storage system

Abstract

To provide a power conditioner capable of creating a space for surplus electric energy in a storage battery of a power storage device more reliably than before.SOLUTION: A power conditioner 10A includes a control unit 50 including a surplus power amount prediction unit 54 and a system charging necessity determination unit 55. The surplus power amount prediction unit 54 predicts the amount of surplus power, which is the difference between the amount of power generated by the photovoltaic power generation device 80 and the amount of power consumed by the home load 85. When the surplus power amount is larger than the available power amount of the storage battery 81a constituting the electrical storage device 81, the storage battery charging necessity determination unit 55 transfers an amount of power calculated by the formula "surplus power amount-available power amount of storage battery 81a" from the storage battery 83a to the storage battery 81a constituting the electric vehicle 83 connected to the charging device 82 for electric motor vehicle, and when the charging ratio of the storage battery 83a does not reach a predetermined target charging ratio due to the transfer, the storage battery 83a is charged using power from the commercial power system 84.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 connecting to a commercial power grid, a solar power generation device, a power storage device, a charging device for an electric vehicle, and a load device. [Background technology]

[0002] Conventionally, a system has been known in which a rectifier that converts AC power supplied from a commercial power system into DC power and outputs it, a solar power generation device, and a power storage device work together to supply the DC power required by a communication device as a load (see, for example, Patent Document 1).

[0003] This system is configured so that when the combined power output by the rectifier and the solar power generation system exceeds the power consumption of the load, the surplus is charged to the storage battery of the power storage system, and when the opposite occurs, the storage battery of the power storage system discharges the shortage. This system also estimates the amount of surplus power, which is the difference between the amount of power generated by the solar power generation system and the amount of power consumed by the load on the following day, and discharges the storage battery of the power storage system in advance to create space for the estimated surplus power. This configuration prevents a portion of the generated power from being wasted as surplus power.

[0004] The part that realizes the transfer of power between the commercial power grid, the solar power generation device, the power storage device, and the load is called a "power conditioner." [Prior art documents] [Non-patent literature]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-100956 Summary of the Invention [Problem to be solved by the invention]

[0006] If the load is a communication device that operates 24 hours a day, such as a wireless base station, the load constantly consumes power, making it possible to create a free battery of surplus energy in the storage device at any time. However, if the load is a typical household load, the load does not always consume power, so even if an attempt is made to discharge the storage battery of the storage device to create a free battery of surplus energy, there is nowhere to discharge the energy, and the battery cannot be discharged. For example, between midnight and 5 a.m., when many people are asleep, typical household loads consume almost no power. For this reason, the conventional system described above could not discharge the storage battery of the storage device to create a free battery of surplus energy between midnight and 5 a.m.

[0007] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a power conditioner and a power storage system that can more reliably create a surplus amount of power in advance in the storage battery of a power storage device than conventional methods. [Means for solving the problem]

[0008] In order to solve the above problems, the power conditioner according to the present invention is used by connecting to a commercial power grid, a solar power generation system, a power storage device including a first storage battery, an electric vehicle charging device connected to an electric vehicle including a second storage battery, and a load device, and includes a power conversion unit located between the commercial power grid and the electric vehicle charging device, a first control unit that controls the power storage device, a second control unit that controls the electric vehicle charging device, a third control unit that controls the power conversion unit, and a control unit that includes a surplus energy prediction unit and a system charging necessity determination unit, and the surplus energy prediction unit calculates a surplus energy amount that is the difference between the amount of power generated by the solar power generation system and the amount of power consumed by the load device. The system charging necessity determination unit predicts the amount of power, and if the amount of surplus power is greater than the amount of available power in the first storage battery, the system charging necessity determination unit causes the storage device to discharge via the first control unit and causes the electric vehicle charging device to charge via the second control unit, thereby transferring an amount of power calculated by the formula "amount of surplus power - amount of available power in the first storage battery" from the first storage battery to the second storage battery, and further, if the charging rate of the second storage battery does not reach a predetermined target charging rate due to the transfer of power from the first storage battery, the system charging necessity determination unit operates the power conversion unit via the third control unit to charge the second storage battery using power from the commercial power system.

[0009] According to this configuration, by discharging to the second storage battery of the electric vehicle, it is possible to create a surplus amount of energy in the first storage battery of the power storage device even when the load device is not consuming power. Also, according to this configuration, it is possible to charge the second storage battery to a target charging rate while minimizing the amount of power supplied to the second storage battery from the commercial power grid.

[0010] It is preferable that the system charging necessity determination unit of the power conditioner is configured to charge the second storage battery using power from the commercial power grid by activating the power conversion unit via the third control unit if it is expected that the transfer of power will not be completed by a predetermined time, even if the charging rate of the second storage battery reaches a target charging rate due to the transfer of power from the first storage battery.

[0011] According to this configuration, the amount of power supplied to the second storage battery from the commercial power system can be minimized, and the second storage battery can be charged to the target state of charge more reliably.

[0012] The grid charging necessity determination unit of the power conditioner may be configured to determine at a predetermined determination time whether to charge the second storage battery using power from the commercial power grid. In this case, it is preferable that the control unit of the power conditioner further includes a load power consumption prediction unit and an electric vehicle power consumption prediction unit, wherein the load power consumption prediction unit predicts, at a predetermined preparation time, the amount of power consumption of the load device until the determination time, the electric vehicle power consumption prediction unit predicts the amount of power consumption of the electric vehicle until the determination time based on information about the state of the electric vehicle acquired at the preparation time, and the first control unit does not cause the power storage device to discharge from the preparation time until the determination time if the amount of power calculated by the formula "surplus power amount - available power amount of the first storage battery at the determination time calculated from the amount of power consumption of the load device" is less than the available power amount of the second storage battery at the determination time calculated from the amount of power consumption of the electric vehicle.

[0013] According to this configuration, by suppressing the consumption of the power stored in the first storage battery between the preparation time and the determination time, the amount of power supplied from the commercial power grid to the second storage battery that constitutes the electric vehicle can be further reduced.

[0014] In order to solve the above-mentioned problems, the present invention provides a power storage system comprising a solar power generation device, a power storage device including a first storage battery, an electric vehicle charging device connected to an electric vehicle including a second storage battery, and a power conditioner connected to these devices, wherein the power conditioner has a power conversion unit located between a commercial power grid and the electric vehicle charging device, and is connected to a load device for use, and the power conditioner comprises a first control unit that controls the power storage device, a second control unit that controls the electric vehicle charging device, a third control unit that controls the power conversion unit, a surplus energy prediction unit, and a grid charging necessity determination unit, and the surplus energy prediction unit calculates the amount of power generated by the solar power generation device and the load The grid charging necessity determination unit predicts the amount of surplus energy, which is the difference between the amount of power consumed by the device and the amount of available energy in the first storage battery, and if the amount of surplus energy is greater than the amount of available energy in the first storage battery, the grid charging necessity determination unit causes the storage device to discharge via the first control unit and causes the electric vehicle charging device to charge via the second control unit, thereby transferring an amount of energy calculated by the formula "amount of surplus energy - amount of available energy in the first storage battery" from the first storage battery to the second storage battery, and further, if the charging rate of the second storage battery does not reach a predetermined target charging rate due to the transfer of energy from the first storage battery, the grid charging necessity determination unit operates the power conversion unit via the third control unit to charge the second storage battery using energy from the commercial power grid. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a power conditioner and a power storage system that can more reliably create a free space in advance for the amount of surplus power in the storage battery of the power storage device than ever before. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a block diagram showing a power storage system including a power conditioner according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing the movement of power in the power conditioner according to the first embodiment of the present invention. [Figure 3] FIG. 3 is a flowchart showing the operation of the grid charging necessity determination unit of the power conditioner according to the first embodiment of the present invention. [Figure 4]FIG. 10 is a block diagram showing a power storage system including a power conditioner according to a second embodiment of the present invention. [Figure 5] FIG. 10 is a diagram showing the movement of power in a power conditioner according to a second embodiment of the present invention. [Figure 6] FIG. 10 is a flowchart showing the operation of a grid charging necessity determination unit of a power conditioner according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a block diagram showing a power storage system including a power conditioner according to a modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] 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.

[0018] [First Example] Fig. 1 shows a power storage system including a power conditioner 10A according to a first embodiment of the present invention. As shown in the figure, power conditioner 10A is used by connecting to a solar power generation device 80, a power storage device 81, an electric vehicle charging device 82, a commercial power system 84, and a household load 85, and includes a DC / DC conversion unit 20, a bidirectional DC / DC conversion unit 30, a bidirectional DC / AC conversion unit 40, and a control unit 50A.

[0019] Solar power generation device 80 includes solar cells 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."

[0020] The power storage device 81 is P S The power storage device 81 includes a storage battery 81a having a storage capacity of [kWh] (see FIG. 2(A)). The power storage device 81 can charge the storage battery 81a with DC power supplied from the bidirectional DC / DC converter 30, and can discharge the storage battery 81a to supply DC power to the bidirectional DC / DC converter 30. The storage battery 81a corresponds to the "first storage battery" of the present invention.

[0021] The charging device 82 for an electric vehicle includes a DC / DC converter 82a and a charging cable 82b. The charging device 82 for an electric vehicle is connected to the P EV The charging device 82 for the electric vehicle is connected to an electric vehicle 83 equipped with a storage battery 83a having a storage capacity of [kWh] (see FIG. 2(B)). The charging device 82 for the electric vehicle can charge the storage battery 83a with DC power supplied from the connection point 11. The storage battery 83a corresponds to the "second storage battery" of the present invention.

[0022] The electric vehicle charging device 82 can also supply DC power to the connection point 11 by discharging the storage battery 83a.

[0023] The connection between the electric vehicle charging device 82 and the electric vehicle 83 may be a contactless connection instead of a connection using the charging cable 82b.

[0024] The electric vehicle 83 is an electric vehicle (EV) or a plug-in hybrid vehicle (PHV).

[0025] The DC / DC converter 20 boosts the DC power output by the solar power generation device 80 and outputs the boosted DC power to the connection point 11.

[0026] The bidirectional DC / DC converter 30 can step down the DC power supplied from the coordination point 11 and supply the stepped-down DC power to the power storage device 81. The bidirectional DC / DC converter 30 can also step up the DC power supplied from the power storage device 81 and supply the stepped-up DC power to the coordination point 11.

[0027] The bidirectional DC / AC conversion unit 40 includes a DC-side input / output terminal connected to the coordination point 11 and an AC-side input / output terminal connected to the commercial power system 84 and the household load 85. The bidirectional DC / AC conversion unit 40 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 40 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 40 corresponds to the "power conversion unit" of the present invention.

[0028] Between the AC side input / output terminal and the commercial power system 84, and between the AC side input / output terminal and the household load 85, there may be switches, relays, etc. not shown in FIG.

[0029] When the amount of power generated by the solar power generation device 80 is relatively large and is greater than the amount of power consumed by the household load 85, the surplus power calculated by the formula "amount of power generated - amount of power consumed" is basically used to charge the storage battery 81a. When an electric vehicle 83 is connected to the electric vehicle charging device 82, part of the surplus power may be used to charge the storage battery 83a.

[0030] On the other hand, when the amount of power generated by the solar power generation device 80 is relatively small (or zero) and is less than the amount of power consumed by the household load 85, the power shortage calculated by the formula "power consumption amount - power generation amount" is covered by at least one of the power supplied from the commercial power grid 84 and the power obtained by discharging the storage battery 81a. In this case, the power of the storage battery 81a is used preferentially.

[0031] The control unit 50A includes a power storage device control unit 51 that controls the operation of the power storage device 81 and the bidirectional DC / DC conversion unit 30, an electric vehicle charging device control unit 52 that controls the operation of the electric vehicle charging device 82, and a bidirectional DC / AC control unit 53 that controls the operation of the bidirectional DC / AC conversion unit 40. The power storage device control unit 51 corresponds to the "first control unit" of the present invention, the electric vehicle charging device control unit 52 corresponds to the "second control unit" of the present invention, and the bidirectional DC / AC control unit 53 corresponds to the "third control unit" of the present invention.

[0032] The control unit 50A further includes a surplus energy prediction unit 54 and a grid charging necessity determination unit 55.

[0033] The surplus power amount prediction unit 54 predicts the surplus power amount P of the day using a trained model created in advance by machine learning using the weather conditions of the day, the amount of power generated in the past, the amount of power consumed in the past, and the like as training data. PV [kWh] (see FIG. 2(A)). The surplus energy prediction unit 54 may also use other methods to predict the surplus energy P PV may be predicted.

[0034] The surplus power prediction unit 54 makes this prediction at midnight. When making a prediction before midnight, the surplus power prediction unit 54 predicts the surplus power P PV This will predict the following.

[0035] The grid charging necessity determination unit 55 calculates the surplus energy amount P PV When the prediction is completed, the available energy amount P S2 [kWh](=storage capacity P S - Remaining power P S1 ) and surplus power P PV Based on this, the amount of surplus power P is stored in the storage battery 81a only by transferring power from the storage battery 81a to the storage battery 83a (hereinafter referred to as "ELEMOVE"; "ELEMOVE" is a registered trademark owned by the applicant). PV It is determined whether or not there is enough free space and the charging rate of the storage battery 83a reaches a predetermined target charging rate (100% in this embodiment).

[0036] The grid charging necessity determination unit 55 calculates the surplus energy amount P PV Once the prediction is completed, the grid charging necessity determination unit 55 immediately makes the determination. In other words, the grid charging necessity determination unit 55 essentially makes the determination at midnight. Note that midnight corresponds to the "determination time" of the present invention.

[0037] Figure 2 shows a schematic representation of the ELEMOVE. PVis the available energy P of the storage battery 81a at midnight. S2 If this is exceeded, the surplus power P PV Since it is not possible to store all of the PV -P S2 The amount of power calculated by " is transferred to the storage battery 83a of the electric vehicle 83.

[0038] The available power amount P of storage battery 83a at midnight EV2 [kWh](=storage capacity P EV - Remaining power P EV1 ) is “P PV -P S2 ", the charging rate of the storage battery 83a can be made 100% by the ELEMOVE, so the system charging necessity determination unit 55 determines that charging of the storage battery 83a with power supplied from the commercial power system 84 (hereinafter referred to as system charging) is not necessary. On the other hand, if the available energy amount P EV2 "P PV -P S2 If the amount of surplus power P is greater than the amount of surplus power P, the charging rate of the storage battery 83a cannot be made 100% by the EleMove alone, so the system charging necessity determination unit 55 determines that it is necessary to make up for the shortage by system charging. PV is the available energy amount P of the storage battery 81a S2 , the grid charging necessity determination unit 55 also determines that grid charging is necessary.

[0039] Naturally, Elemove requires the amount of power to be moved, "P PV -P S2 ". Furthermore, charging of the storage battery 83a must be completed by a predetermined time (for example, 6:00) to prevent a decrease in the convenience of the electric vehicle 83 and to be performed during a time period when electricity rates are low. For this reason, when making the above determination, the grid charging necessity determination unit 55 also takes into consideration whether or not the Elemove will be completed by the predetermined time.

[0040] The determination made by grid charging necessity determination unit 55 will be specifically described with reference to FIG.

[0041] In step S1-1, the grid charging necessity determination unit 55 determines whether or not "P PV -P S2 Determine whether "P" is greater than 0. PV -P S2 If " is greater than 0, proceed to step S1-2. PV -P S2 If " is equal to or less than 0, proceed to step S1-6.

[0042] In step S1-2, the grid charging necessity determination unit 55 determines whether or not "P PV -P S2 " is P EV2 Determine whether it is greater than "P PV -P S2 " is P EV2 If it is greater than , proceed to step S1-3 and PV -P S2 " is P EV2 If it is equal to or less than this, proceed to step S1-5.

[0043] In step S1-3, the grid charging necessity determination unit 55 determines whether or not "P PV -P S2 It is determined whether the "elemove" of "" will be completed by the predetermined time (6 o'clock), that is, whether it will be in time. If it will be in time, the process proceeds to step S1-4, and if it will not be in time, the process proceeds to step S1-5.

[0044] In step S1-4, grid charging necessity determination unit 55 determines that grid charging is unnecessary because the storage battery 83a of electric vehicle 83 can be charged to the target charging rate by the predetermined time using only Elemove. In this case, grid charging necessity determination unit 55 causes the power storage device 81 to discharge via the power storage device control unit 51 and causes the electric vehicle charging device 82 to charge via the electric vehicle charging device control unit 52.

[0045] In step S1-5, system charging necessity determination unit 55 determines that system charging together with Elemove is necessary because the storage battery 83a of electric vehicle 83 cannot be charged to the target charging rate by the predetermined time using only Elemove. In this case, system charging necessity determination unit 55 causes the power storage device 81 to discharge via the power storage device control unit 51, causes the electric vehicle charging device 82 to charge via the electric vehicle charging device control unit 52, and further operates the bidirectional DC / AC conversion unit 40 via the bidirectional DC / AC control unit 53.

[0046] In step S1-6, the grid charging necessity determination unit 55 determines that grid charging is necessary because there is no power available for removal. In this case, the grid charging necessity determination unit 55 activates the bidirectional DC / AC conversion unit 40 via the bidirectional DC / AC control unit 53.

[0047] In this way, according to the power conditioner 10A of this embodiment, by discharging to the storage battery 83a of the electric vehicle 83, it is possible to create a surplus amount of energy in the storage battery 81a of the power storage device 81 even when the household load 85 is not consuming power, by discharging to the storage battery 83a of the electric vehicle 83. Furthermore, according to the power conditioner 10A of this embodiment, by supplying the minimum necessary amount of power from the commercial power grid 84, it is possible to reliably charge the storage battery 83a of the electric vehicle 83 to the target charging rate by a predetermined time.

[0048] [Second Example] 4 shows a power storage system including a power conditioner 10B according to a second embodiment of the present invention. As shown in the figure, power conditioner 10B differs from power conditioner 10A in that it includes a control unit 50B instead of control unit 50A and in that it also includes a communication unit 60, but is otherwise similar to power conditioner 10A. However, power conditioner 10A and power conditioner 10B also differ slightly in the operation of surplus energy prediction unit 54 and grid charging necessity determination unit 55.

[0049] The communication unit 60 can obtain information about the state of the electric vehicle 83 by wireless communication. The communication unit 60 may obtain the information directly from the electric vehicle 83, may obtain the information indirectly via an appropriate relay device, or may obtain the information from a server that stores information about the electric vehicle 83.

[0050] The information about the electric vehicle 83 acquired by the communication unit 60 includes, for example, the current position of the electric vehicle 83, the current number of passengers, the current usage status of electrical components, and the current remaining amount of power in the storage battery 83a.

[0051] The control unit 50B is configured by adding a load power consumption prediction unit 56 and an electric vehicle power consumption prediction unit 57 to the control unit 50A.

[0052] When the time when the power generation by the solar power generation device 80 is about to end (for example, 5 p.m.) is reached, the load power consumption prediction unit 56 uses a trained model created in advance by machine learning using the past power consumption amount of the household load 85 as training data to predict the power consumption amount P of the household load 85 from 5 p.m. to midnight of the next day (hereinafter referred to as load power consumption amount). L Then, the load power consumption prediction unit 56 predicts the available power P S4 [kWh](=storage capacity P S - Remaining power P S3 ) and the predicted load power consumption P L Based on this, the available power amount of the storage battery 81a at midnight of the next day is calculated. L As a result, the available power of the storage battery 81a at midnight on the following day is "P S4 +P L ". 17:00 corresponds to the "preparation time" of the present invention.

[0053] At the preparation time (17:00), the electric vehicle power consumption prediction unit 57 calculates the power consumption of the electric vehicle 83 from 17:00 to midnight (hereinafter referred to as electric vehicle power consumption) P based on the information on the electric vehicle 83 acquired by the communication unit 60. DFor example, the electric vehicle power consumption prediction unit 57 predicts the position of the electric vehicle 83 at 5 p.m. (i.e., the distance from the electric vehicle charging device 82 to the electric vehicle 83) and the remaining energy P EV3 Using a trained model created in advance by machine learning using training data such as [kWh], the electric vehicle power consumption P D Then, the electric vehicle power consumption prediction unit 57 predicts the available power amount P EV4 [kWh](=storage capacity P EV - Remaining power P EV3 ) and the predicted electric vehicle power consumption P D Based on this, the available power amount of the storage battery 83a at midnight on the following day is calculated. The power stored in the storage battery 83a on the way home until arriving at the electric vehicle charging device 82 is P D As a result, the available power of the storage battery 83a at midnight on the following day is "P EV4 +P D "

[0054] The surplus power amount prediction unit 54 calculates the surplus power amount P for the next day at 5:00 PM (preparation time) instead of at midnight (determination time). PV Predict.

[0055] After 5 p.m., when the amount of power generated by the solar power generation device 80 starts to decrease, the power storage device control unit 51 causes the power storage device 81 to discharge, and supplies the power stored in the storage battery 81a to the household load 85. However, the power storage device control unit 51 controls the amount of surplus power P PV and the available energy amount of the storage battery 81a at midnight of the next day, “P S4 +P L " and the difference "P PV -(P S4 +P L )” is the free energy amount of the storage battery 83a at midnight of the next day, “P EV4 +P D ", the power storage device 81 is not allowed to discharge between 5 pm and midnight. In this case, power is supplied from the commercial power grid 84 to the household load 85.

[0056] As shown in FIG. 6, the grid charging necessity determination unit 55 PV -P S2 "P" instead of " PV -(P S4 +P L ), and P EV2 Instead of "P EV4 +P D " is used to perform the determinations in steps S2-1 to S2-3. Steps S2-4 to S2-6 correspond to steps S1-4 to S1-6 in the first embodiment.

[0057] In this way, according to the power conditioner 10B of this embodiment, by suppressing the consumption of the power stored in the storage battery 81a from the preparation time to the judgment time, it is possible to reduce or completely eliminate the amount of system charging performed together with Elemove after the judgment time.

[0058] Although the first and second 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.

[0059] [Variations] For example, the power conditioner according to the present invention may have a configuration similar to that of the power conditioner 10C shown in Fig. 7, i.e., a configuration including a control unit 50C instead of the control unit 50A. The control unit 50C differs from the control unit 50A in that it further includes an electric vehicle usage prediction unit 58.

[0060] The electric vehicle usage prediction unit 58 determines the target charging rate based on at least one of the past usage status of the electric vehicle 83 and the schedule of the person using the electric vehicle 83 for that day. For example, the electric vehicle usage prediction unit 58 predicts the traveling distance of the electric vehicle 83 for that day from the past usage status of the electric vehicle 83 and the user's schedule, and determines the target charging rate according to the predicted traveling distance. If the traveling distance is relatively short, the electric vehicle usage prediction unit 58 sets the target charging rate to, for example, 60%. In this case, the grid charging necessity determination unit 55 determines whether grid charging is necessary to bring the charging rate of the storage battery 83a of the electric vehicle 83 to 60%. With this configuration, the amount of grid charging performed together with the Elemove can be further reduced.

[0061] 1, 4, and 7 depict control units 51, 52, and 53, prediction units 54, 56, 57, and 58, determination unit 55, and bidirectional DC / AC conversion unit 40, etc. as components of power conditioners 10A to 10C, but all or part of control units 51, 52, and 53, prediction units 54, 56, 57, and 58, and determination unit 55 may be arranged outside power conditioners 10A to 10C.

[0062] Furthermore, although FIGS. 1, 4, and 7 depict the DC / DC conversion unit 20 and the bidirectional DC / DC conversion unit 30 as components of the power conditioners 10A to 10C housed in the same housing, all or part of these may be housed in separate housings.

[0063] Furthermore, midnight in the first and second embodiments is merely an example of the determination time. In the present invention, it is preferable to set the determination time between 11:00 PM and 3:00 AM the next day, when the amount of power consumption of the household load 85 is low and there is ample time before the start of use of the electric vehicle 83.

[0064] 17:00 in the second embodiment is merely an example of the preparation time. In the present invention, it is preferable to set the preparation time between 16:00 and 19:00, when the amount of power generated by the solar power generation device 80 is low and there is ample time until the determination time. If the time from the preparation time to the determination time is short, it is not possible to sufficiently reduce the amount of grid charging performed together with Elemove. [Explanation of symbols]

[0065] 10A, 10B, 10C power conditioner 11 Linkage Points 20 DC / DC conversion section 30 Bidirectional DC / DC conversion section 40 Bidirectional DC / AC conversion section 50A, 50B, 50C Control section 51 Power storage device control unit (first control unit) 52 Electric vehicle charging device control unit (second control unit) 53 Bidirectional DC / AC control section (third control section) 54 Surplus power prediction unit 55 Grid charging necessity determination unit 56 Load power consumption prediction unit 57 Electric vehicle power consumption prediction unit 58 Electric Vehicle Usage Forecasting Department 60 Communications Department 80 Solar power generation equipment 81 Power storage device 81a Storage battery (first storage battery) 82 Charging device for electric vehicles 82a DC / DC conversion unit 82b charging cable 83 Electric vehicle 83a Storage battery (second storage battery) 84 Commercial power system 85 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 charging 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 device; a control unit including a first control unit that controls the power storage device, a second control unit that controls the electric vehicle charging device, a third control unit that controls the power conversion unit, a surplus energy prediction unit, and a grid charging necessity determination unit; Equipped with the surplus power prediction unit predicts an amount of surplus power, which is a difference between an amount of power generated by the solar power generation device and an amount of power consumed by the load device; When the amount of surplus energy is greater than the amount of available energy of the first storage battery at a predetermined determination time, the grid charging necessity determination unit determines, at the determination time, whether grid charging is necessary based on whether the charging rate of the second storage battery reaches a predetermined target charging rate by transferring an amount of power calculated by the formula "the amount of surplus energy - the amount of available energy of the first storage battery at the determination time" from the first storage battery to the second storage battery, and (1) when the target charging rate is reached, the grid charging necessity determination unit causes the power storage device to discharge via the first control unit and the electric vehicle charging device to charge via the second control unit, thereby transferring the calculated amount of power from the first storage battery to the second storage battery, and (2) when the target charging rate is not reached, the grid charging necessity determination unit transfers the calculated amount of power from the first storage battery to the second storage battery and also causes the power conversion unit to operate via the third control unit to perform grid charging of the second storage battery using power from the commercial power grid, The charging device for an electric vehicle can also discharge the second storage battery, The determination time is set to a time when the grid charging is completed during a time period when electricity rates are low. A power conditioner characterized by the above.

2. Even if the charging rate of the second storage battery reaches the target charging rate due to the transfer of power from the first storage battery, if it is expected that the transfer of power will not be completed by a predetermined time, the system charging necessity determination unit operates the power conversion unit via the third control unit to charge the second storage battery using power from the commercial power system. The power conditioner according to claim 1 .

3. the control unit further includes a load power consumption prediction unit and an electric vehicle power consumption prediction unit; the load power consumption prediction unit predicts, at a predetermined preparation time, the power consumption of the load device until the determination time; the electric vehicle power consumption prediction unit predicts the amount of power consumption of the electric vehicle until the determination time based on information about the state of the electric vehicle acquired at the preparation time; When the amount of power calculated by the formula "the surplus power amount - the available power amount of the first storage battery at the determination time calculated from the power consumption amount of the load device" is smaller than the available power amount of the second storage battery at the determination time calculated from the power consumption amount of the electric vehicle, the first control unit does not allow the power storage device to discharge during the period from the preparation time to the determination time. The power conditioner according to claim 2 .

4. A power storage system comprising: a solar power generation device; a power storage device including a first storage battery; an electric vehicle charging device connected to an electric vehicle including a second storage battery; and a power conditioner connected to these devices, wherein the power conditioner has a power conversion unit located between a commercial power system and the electric vehicle charging device, and is connected to a load device for use; a first control unit that controls the power storage device; a second control unit that controls the electric vehicle charging device; a third control unit that controls the power conversion unit; a surplus power amount prediction unit; Grid charging necessity determination unit Equipped with the surplus power prediction unit predicts an amount of surplus power, which is a difference between an amount of power generated by the solar power generation device and an amount of power consumed by the load device; When the amount of surplus energy is greater than the amount of available energy of the first storage battery at a predetermined determination time, the grid charging necessity determination unit determines, at the determination time, whether grid charging is necessary based on whether the charging rate of the second storage battery reaches a predetermined target charging rate by transferring an amount of power calculated by the formula "the amount of surplus energy - the amount of available energy of the first storage battery at the determination time" from the first storage battery to the second storage battery, and (1) when the target charging rate is reached, the grid charging necessity determination unit causes the power storage device to discharge via the first control unit and the electric vehicle charging device to charge via the second control unit, thereby transferring the calculated amount of power from the first storage battery to the second storage battery, and (2) when the target charging rate is not reached, the grid charging necessity determination unit transfers the calculated amount of power from the first storage battery to the second storage battery and also causes the power conversion unit to operate via the third control unit to perform grid charging of the second storage battery using power from the commercial power grid, The charging device for an electric vehicle can also discharge the second storage battery, The determination time is set to a time when the grid charging is completed during a time period when electricity rates are low. A power storage system characterized by:

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