Charging / discharging device and charging / discharging system

Abstract

To provide a charge / discharge device which reduces the number of reception times of a stop signal from an electric vehicle and can further improve convenience.SOLUTION: A charge / discharge device 20 includes a vehicle connection unit 21, a power conversion unit 22 and a control unit 23. The control unit 23 performs connection processing for performing connection operation of the vehicle connection unit 21 and an electric vehicle 70; charge / discharge start processing for allowing the power conversion unit 22 to start charge / discharge operation, information acquisition processing for acquiring battery information on an upper limit value and a lower limit value of SOC of an on-vehicle battery 71 from the electric vehicle 70 between the connection processing and the charge / discharge start processing, and limit value setting processing for setting a charge limit value to a value smaller than the upper limit value and setting a discharge limit value to a value larger than the lower limit value between the information acquisition processing and the charge / discharge start processing. The power conversion unit 22 performs charge / discharge operation in a charge / discharge band from the discharge limit value to the charge limit value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a charging / discharging device and a charging / discharging system for charging / discharging an on-board battery. [Background technology]

[0002] A known example of a charging / discharging device for charging / discharging an onboard battery is described in Patent Document 1. The charging / discharging device described in Patent Document 1 charges an onboard battery of an electrically powered vehicle such as an electric vehicle using power generated by a solar power generation device and commercial power (grid power) supplied from a power grid. With this charging / discharging device, the user can select between a mode in which the onboard battery is charged using only the generated power, and a mode in which the onboard battery is charged using both the generated power and commercial power.

[0003] As shown in Figure 6, when the SOC of the onboard battery reaches a predetermined upper limit (e.g., SOC 90%) or a predetermined lower limit (e.g., SOC 20%), a typical electric vehicle sends a stop signal regarding a normal stop to the charging / discharging device, and opens the contactor based on an instruction from the charging / discharging device to disconnect the onboard battery from the charging / discharging device.

[0004] In a conventional charging / discharging device that uses power generated by a solar power generation system to charge an onboard battery, if the onboard battery's SOC is close to its upper limit, there is a possibility that charging will be completed (stopped) and then discharged repeatedly. In this case, the contactor on the electric vehicle side will be opened and closed many times, shortening the contactor's lifespan.

[0005] Furthermore, each time the charging / discharging device receives a stop signal from the electric vehicle, it temporarily disconnects and reconnects the electric vehicle. When reconnecting, the charging / discharging device performs predetermined processing, such as insulation diagnosis. This means that it takes time to resume charging / discharging, and during this time, the power generated by the solar power generation system cannot be used effectively.

[0006] The present inventors have invented a charging / discharging device to solve the above problems (see Patent Document 2). This charging / discharging device can reduce the number of times it receives a stop signal from an electric vehicle by setting a charge limit value and a discharge limit value, without excessively narrowing the SOC band (charge / discharge band) of the onboard battery. However, because this charging / discharging device needs to receive a stop signal from the electric vehicle once during charging and once during discharging in order to set the charge limit value and the discharge limit value (because the process of disconnecting and reconnecting the electric vehicle with the device needs to be performed once during charging and once during discharging), further improvements in convenience were desired. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-228714 [Patent Document 2] Japanese Patent Publication No. 2020-18120 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a charging / discharging device and a charging / discharging system that can reduce the number of times a stop signal is received from an electric vehicle and further improve convenience. [Means for solving the problem]

[0009] In order to solve the above problems, the charging / discharging device according to the present invention comprises: a vehicle connection unit configured to be connectable to an electric vehicle; a power conversion unit that performs charging and discharging operations on an on-board battery of the electric vehicle via the vehicle connection unit; a control unit that controls the charging operation and the discharging operation of the power conversion unit; A charging / discharging device comprising: The control unit a connection process for performing a connection operation between the vehicle connection unit and the electric vehicle; a charge / discharge start process for causing the power conversion unit to start the charging operation or the discharging operation; an information acquisition process, performed between the connection process and the charge / discharge start process, for acquiring battery information relating to an upper limit value and a lower limit value of a SOC of the on-board battery from the electric vehicle; a limit value setting process for setting a discharge limit value during the discharging operation to a value greater than the lower limit value between the information acquisition process and the charge / discharge start process; The power conversion unit performs the charging operation and the discharging operation in a charging / discharging band equal to or greater than the discharge limit value.

[0010] In this configuration, between the information acquisition process and the charge / discharge start process, the control unit sets a discharge limit value, and the power conversion unit performs charging and discharging operations in a charge / discharge band equal to or greater than the discharge limit value. Therefore, with this configuration, it is possible to reduce the number of times a stop signal is received from the electric vehicle to zero, at least during discharging operations, thereby further improving convenience.

[0011] In the charging / discharging device, When the control unit acquires the total battery capacity value of the on-board battery without acquiring an SOC value corresponding to the upper limit value as the battery information, the control unit can be configured to convert the total battery capacity value into an SOC value of the on-board battery and set the SOC value as the upper limit value.

[0012] In the charging / discharging device, The control unit may be configured to set the charge limit value during the charging operation to a value smaller than the upper limit value between the information acquisition process and the charge / discharge start process as the limit value setting process; The control unit The charge / discharge band is set to a band from the discharge limit value to the upper limit value, When a stop signal for stopping the charging operation is received from the electric vehicle during the charging operation, the charge / discharge band is changed to a band from the discharge limit value to a charge limit value that is smaller than the upper limit value, The power conversion unit may be configured to perform the charging operation and the discharging operation in the changed charging / discharging band.

[0013] In the charging / discharging device, when the control unit receives a stop signal from the electric vehicle during the charging operation or the discharging operation to stop the charging operation or the discharging operation, the control unit executes a limit value change process to change at least one of the charging limit value or the discharging limit value to narrow the charging / discharging band; The power conversion unit may be configured to perform the charging operation and the discharging operation in the changed charging / discharging band.

[0014] In order to solve the above problem, the charge / discharge system according to the present invention comprises: A charging / discharging system including the charging / discharging device and a power conditioner device, The power conditioner device is connected to the charging / discharging device, the power generation device, and the load, and is characterized by performing the operations of supplying the power generated by the power generation device to the charging / discharging device, and converting the DC power input from the charging / discharging device into AC power and supplying it to the load.

[0015] The charging / discharging system includes: further comprising a storage battery; The power conditioner device can be configured to perform an operation of charging the storage battery and an operation of discharging the storage battery. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a charging / discharging device and a charging / discharging system that can reduce the number of times a stop signal is received from an electric vehicle and further improve convenience. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a block diagram of a charging / discharging device and a charging / discharging system according to the present invention. [Figure 2]FIG. 2 is a block diagram of a control unit of the charging / discharging device according to the present invention. [Figure 3] 4 is a flowchart of the charge / discharge control according to the present invention before the start of charge / discharge processing. [Figure 4] 4 is a flowchart of the charge / discharge control according to the present invention after the charge / discharge start process. [Figure 5] 10 is a graph showing changes in the SOC of an in-vehicle battery during charge / discharge control according to a modified example. [Figure 6] 1 is a graph showing changes in SOC of an in-vehicle battery during conventional charge / discharge control. DETAILED DESCRIPTION OF THE INVENTION

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a charging / discharging device and a charging / discharging system according to the present invention will be described with reference to the accompanying drawings.

[0019] 1 shows a charge / discharge system 1 according to one embodiment of the present invention. The charge / discharge system 1 includes a power conditioner device 10, a charge / discharge device 20 according to one embodiment of the present invention, and a storage battery 30.

[0020] The power conditioner device 10 includes a first converter unit 11, a second converter unit 12, an inverter unit 13, and a power conditioner control unit 14. The power conditioner device 10 is connected to a storage battery 30, a solar power generation device 40, a load (domestic load) 50, and a power grid 60.

[0021] The first converter unit 11 is, for example, a DC / DC converter configured with a boost chopper circuit. The first converter unit 11 performs MPPT operation (maximum power point tracking operation) on the power generated by the solar power generation device 40 under the control of the power conditioner control unit 14. The first converter unit 11 boosts the power generated by the solar power generation device 40 and outputs DC power.

[0022] The second converter unit 12 is, for example, a bidirectional DC / DC converter configured with a bidirectional chopper circuit. The second converter unit 12 charges and discharges the storage battery 30 under the control of the power conditioner control unit 14.

[0023] The inverter unit 13 is, for example, a bidirectional AC / DC converter. An AC terminal side of the inverter unit 13 is connected to the load 50 and the power grid 60, and a DC terminal side is connected to the first converter unit 11 and the second converter unit 12. The inverter unit 13 converts system power supplied from the power grid 60 into DC power and supplies it to the second converter unit 12, and converts DC power input to the DC terminal into AC power and supplies it to the load 50 and the power grid 60.

[0024] The power conditioner control unit 14 is configured with an analog control circuit, a digital control circuit using a microcontroller or the like, or a circuit that combines an analog control circuit and a digital control circuit. The power conditioner control unit 14 controls the first converter unit 11, the second converter unit 12, and the inverter unit 13 while switching between multiple operation modes.

[0025] The power conditioner device 10 has two operating modes: an economic mode and a green mode. The economic mode is a mode that emphasizes economy, in which all surplus power generated by the solar power generation device 40 is output to the power grid and sold. On the other hand, the green mode is a mode in which the surplus power generated by the solar power generation device 40 is used to charge an electric vehicle 70, such as an electric vehicle or a plug-in hybrid vehicle, connected to the charging / discharging device 20, or to charge the storage battery 30. In this embodiment, charging of the electric vehicle 70 is given priority, and the storage battery 30 is charged only when the electric vehicle 70 is not being charged.

[0026] When the operating mode is the green mode and the power generated by the solar power generation device 40 is greater than the power consumed by the load 50, the surplus power is preferentially supplied to the electric vehicle 70. For example, if the generated power is 4 kW and the power consumed by the load 50 is 3 kW, the surplus of 1 kW is supplied to the electric vehicle 70. On the other hand, when the operating mode is the green mode and the generated power of the solar power generation device 40 is less than the power consumed by the load 50, the shortfall in the generated power is made up for by the electric vehicle 70. For example, if the generated power is 2 kW and the power consumed by the load 50 is 3 kW, the shortfall of 1 kW is supplied from the electric vehicle 70.

[0027] In this way, when the operating mode is the green mode, the charging operation and discharging operation of the electric vehicle 70 are frequently switched depending on the situation of the power generated by the solar power generation device 40 and the power consumption of the load 50.

[0028] A charging / discharging device 20 according to one embodiment of the present invention is, for example, a V2H (Vehicle to Home) stand, and includes a vehicle connection unit 21, a power conversion unit 22, and a control unit .

[0029] Vehicle connection unit 21 is configured to be connected to electric vehicle 70. Vehicle connection unit 21 includes a connector and a cable. The connector of vehicle connection unit 21 is, for example, a charge / discharge connector that complies with the CHAdeMO standard.

[0030] The power conversion unit 22 is, for example, a bidirectional DC / DC converter, and performs charging and discharging operations (charging operation and discharging operation) on the on-board battery 71 of the electric vehicle 70. In the electric vehicle 70, a contactor 72 is interposed in the power line connecting the power conversion unit 22 and the on-board battery 71.

[0031] The control unit 23 is configured with an analog control circuit, a digital control circuit using a microcontroller or the like, or a circuit that combines an analog control circuit and a digital control circuit. As shown in Fig. 2, the control unit 23 includes a communication unit 24, a storage unit 25, a limit value setting unit 26, and a charge / discharge control unit 27.

[0032] The communication unit 24 is configured to communicate with the power conditioner control unit 14 and the vehicle control unit 73. Communication with the vehicle control unit 73 (for example, CAN communication or PLC communication) is performed via the vehicle connection unit 21.

[0033] Before the power conversion unit 22 starts a charging / discharging operation, the communication unit 24 receives battery information from the vehicle control unit 73. The battery information is information relating to the upper and lower limits of the SOC of the in-vehicle battery 71, and specifically includes the SOC value and / or total battery capacity value corresponding to the upper limit and the SOC value corresponding to the lower limit. Even while the power conversion unit 22 is performing a charging / discharging operation, the communication unit 24 receives various information (e.g., the SOC value and command signals of the in-vehicle battery 71) from the vehicle control unit 73.

[0034] Regarding the upper and lower limit values of the SOC of the vehicle battery 71, when the SOC of the vehicle battery 71 reaches the upper or lower limit value, the electric vehicle 70 sends a stop signal regarding a normal stop to the control unit 23 and opens the contactor 72 to disconnect the vehicle battery 71 from the power conversion unit 22.

[0035] The storage unit 25 stores information received by the communication unit 24, information set by the limit value setting unit 26, etc. The information stored in the storage unit 25 can also be shared by the communication unit 24, the limit value setting unit 26, and the charge / discharge control unit 27.

[0036] The limit value setting unit 26 is configured to set a charge limit value and a discharge limit value. Specifically, the limit value setting unit 26 sets the charge limit value during a charge operation to a value smaller than the upper limit value, and sets the discharge limit value during a discharge operation to a value larger than the lower limit value, based on the battery information received by the communication unit 24. In this embodiment, the charge limit value is set to a value 5% smaller than the upper limit value, and the discharge limit value is set to a value 5% larger than the lower limit value.

[0037] When a stop signal is received from the vehicle control unit 73, the limit value setting unit 26 changes at least one of the set charge limit value or discharge limit value. In this embodiment, when the operation of the power conversion unit 22 is a charging operation, the limit value setting unit 26 stores the SOC value of the in-vehicle battery 71 at the time the stop signal is received as an upper limit value in the storage unit 25. When the operation of the power conversion unit 22 is a discharging operation, the limit value setting unit 26 stores the SOC value of the in-vehicle battery 71 at the time the stop signal is received as a lower limit value in the storage unit 25. Then, the limit value setting unit 26 sets the charge limit value to a value 5% smaller than the upper limit value stored in the storage unit 25, and sets the discharge limit value to a value 5% larger than the lower limit value stored in the storage unit 25.

[0038] The charge / discharge control unit 27 performs a connection operation (connector lock operation) between the vehicle connection unit 21 and the electric vehicle 70 while the connector of the vehicle connection unit 21 is connected to the electric vehicle 70. After the charge limit value and the discharge limit value are set by the limit value setting unit 26, the charge / discharge control unit 27 causes the power conversion unit 22 to start a charge / discharge operation.

[0039] During charging and discharging operations, the charge / discharge control unit 27 stops the charging operation of the power conversion unit 22 when the SOC value of the in-vehicle battery 71 reaches the charge limit value, and stops the discharging operation of the power conversion unit 22 when the SOC value of the in-vehicle battery 71 reaches the discharge limit value. As a result, the power conversion unit 22 performs charging and discharging operations only in the charge / discharge band from the discharge limit value to the charge limit value.

[0040] When the charge / discharge control unit 27 receives a stop signal from the vehicle control unit 73 during a charge / discharge operation, the charge / discharge control unit 27 stops the charge / discharge operation and performs a disconnection operation to release the connection with the electric vehicle 70, and a reconnection operation to resume the connection with the electric vehicle 70 after the disconnection operation. The disconnection operation includes an operation to open the contactor 72 through an opening command from the vehicle control unit 73 (an operation to send an opening command for the contactor 72 to the vehicle control unit 73), and an operation to cut off communication with the vehicle control unit 73. The reconnection operation includes an operation to resume communication with the vehicle control unit 73 and an operation to close the contactor 72 through a closing command from the vehicle control unit 73 (an operation to send a closing command for the contactor 72 to the vehicle control unit 73). The charge / discharge control unit 27 resumes the charge / discharge operation after the reconnection operation.

[0041] 3 and 4, a method for controlling charging and discharging of the in-vehicle battery 71 performed by the control unit 23 will be described. Here, it is assumed that the operation mode of the power conditioner device 10 is the green mode, and that a time period is available in which surplus power generated by the solar power generation device 40 can be used to charge the in-vehicle battery 71.

[0042] When the connector of vehicle connection unit 21 is connected to electric vehicle 70 (when a connector lock button is pressed if charging / discharging device 20 is provided with one), control unit 23 performs a connection process. During the connection process, charge / discharge control unit 27 of control unit 23 performs a connection operation (connector lock operation) between vehicle connection unit 21 and electric vehicle 70 (S1). The connection operation locks the connector of vehicle connection unit 21 to electric vehicle 70.

[0043] When the connector of the vehicle connection unit 21 is locked to the electric vehicle 70, the control unit 23 performs an information acquisition process. During the information acquisition process, the communication unit 24 of the control unit 23 acquires battery information relating to the lower and upper limits of the SOC of the on-board battery 71 from the vehicle control unit 73 (S2).

[0044] In this embodiment, the battery information related to the lower limit value includes an SOC value corresponding to the lower limit value. The communication unit 24 acquires, for example, battery information such as "lower limit value=20[%]." The battery information corresponding to the upper limit value includes an SOC value corresponding to the upper limit value and / or the total battery capacity value of the in-vehicle battery 71. The communication unit 24 acquires, for example, battery information such as "upper limit value=90[%]," or battery information such as "total battery capacity value=X[kWh]."

[0045] When the battery information corresponding to the upper limit is a total battery capacity value, the limit value setting unit 26 converts the total battery capacity value to an SOC value of the in-vehicle battery 71 and sets the SOC value as the upper limit. For example, the total battery capacity value = X [kWh] is set to SOC100 [%], and the upper limit is set to SOC100 [%]. Note that even when the battery information corresponding to the upper limit is an SOC value, if the SOC value is smaller than the SOC value corresponding to the lower limit (for example, when battery information indicating "lower limit = 20 [%]" and "upper limit = 5 [%]" is acquired), the limit value setting unit 26 considers that an SOC value corresponding to the upper limit has not been acquired, converts the total battery capacity value to an SOC value of the in-vehicle battery 71, and sets the SOC value as the upper limit.

[0046] After acquiring the battery information, the control unit 23 performs a limit value setting process. During the limit value setting process, the control unit 23 causes the limit value setting unit 26 to set a charge limit value and a discharge limit value (S3). In this embodiment, the limit value setting unit 26 sets the charge limit value to a value 5% smaller than the upper limit value, and sets the discharge limit value to a value 5% larger than the lower limit value.

[0047] After setting the charge limit value and the discharge limit value, the control unit 23 performs a charge / discharge start process. During the charge / discharge start process, the control unit 23 causes the charge / discharge control unit 27 to cause the power conversion unit 22 to start a charge / discharge operation (S4).

[0048] The charge / discharge control unit 27, which has caused the power conversion unit 22 to start the charge / discharge operation, controls the power conversion unit 22 so that the power conversion unit 22 performs the charge / discharge operation in a charge / discharge band from the discharge limit value to the charge limit value (S5). That is, the charge / discharge control unit 27 stops the charging operation when the SOC of the in-vehicle battery 71 reaches the charge limit value, and stops the discharging operation when the SOC of the in-vehicle battery 71 reaches the discharge limit value.

[0049] If the battery information acquired by the information acquisition process is not accurate, communication unit 24 may receive a stop signal from vehicle control unit 73 (YES in S6). When communication unit 24 receives the stop signal, charge / discharge control unit 27 stops the charge / discharge operation of power conversion unit 22 and performs a parallel-off operation (S7).

[0050] Next, the charge / discharge control unit 27 determines whether a first condition related to the upper limit value is satisfied (S8). The first condition is that the SOC of the vehicle battery 71 immediately before the parallel-off operation is equal to or greater than a first threshold value (70% in this embodiment) and the operation of the power conversion unit 22 when the stop signal is received is a charging operation. From this determination, the charge / discharge control unit 27 can infer that the vehicle battery 71 is fully charged (or close to fully charged). If the charge / discharge control unit 27 determines that the first condition is satisfied (YES in S8), it performs a reconnection operation (S9).

[0051] The communication unit 24 receives information about the current SOC value of the in-vehicle battery 71 from the vehicle control unit 73, and stores the SOC value as an upper limit in the storage unit 25 (S10). The limit value setting unit 26 changes the charge limit value to a value smaller than the upper limit stored in the storage unit 25 (upper limit value -5% in this embodiment) (S11). For example, if the charge / discharge band before the change is SOC 10% to 80%, the charge / discharge band after the change will be SOC 10% to 75%. The processes of S10 and S11 above correspond to the "limit value change process" of the present invention.

[0052] If the charge / discharge control unit 27 determines in S8 above that the first condition is not met (NO in S8), it then determines whether a second condition related to the lower limit is met (S12). The second condition is that the SOC of the vehicle battery 71 immediately before the parallel-off operation is equal to or less than a second threshold value (40% in this embodiment) and the operation of the power conversion unit 22 when the stop signal is received is a discharging operation. This allows the charge / discharge control unit 27 to infer that the vehicle battery 71 is empty (or close to empty). If the control unit 23 determines that the second condition is met (YES in S12), it performs a reconnection operation (S13).

[0053] The communication unit 24 receives information about the current SOC value of the in-vehicle battery 71 from the vehicle control unit 73, and stores the SOC value as a lower limit in the storage unit 25 (S14). The limit value setting unit 26 changes the discharge limit value to a value greater than the lower limit stored in the storage unit 25 (in this embodiment, the lower limit value + 5%) (S15). For example, if the charge / discharge band before the change is SOC 10% to 80%, the charge / discharge band after the change will be SOC 15% to 80%. The processes in S14 and S15 above correspond to the "limit value change process" of the present invention.

[0054] Incidentally, when charging and discharging of several hundred watts or less continues for a predetermined time, the vehicle control unit 73 may send a stop signal to the control unit 23 even if the SOC of the in-vehicle battery 71 has not reached the upper or lower limit. In this case, the charge and discharge control unit 27 determines in step S8 that the first condition is not satisfied (NO in S8) and determines in step S12 that the second condition is not satisfied (NO in S12). Then, the charge and discharge control unit 27 transitions to a standby state without performing a reconnection operation, without storing the upper and lower limit values, and without changing the charge limit value and the discharge limit value (S16).

[0055] In charging / discharging device 20 according to this embodiment, limit value setting unit 26 sets a charge limit value and a discharge limit value before power conversion unit 22 starts a charge / discharge operation, and power conversion unit 22 performs a charge / discharge operation in a charge / discharge band from the discharge limit value to the charge limit value. Therefore, charging / discharging device 20 can reduce the number of times a stop signal is received from electric vehicle 70 to zero, further improving convenience.

[0056] Furthermore, if the acquired battery information is inaccurate, control unit 23 of charging / discharging device 20 executes a limit value change process to narrow the charging / discharging band when it receives a stop signal from vehicle control unit 73. This makes it possible to avoid receiving a second stop signal.

[0057] [Variations] Although the embodiments of the charge / discharge device and the charge / discharge system according to the present invention have been described above, the present invention is not limited to the above-described embodiments.

[0058] In the above embodiment, the control unit 23 may set the charge / discharge band to a band from the discharge limit value to the upper limit value. Fig. 5 shows the change in SOC of the in-vehicle battery 71 during charge / discharge control in this modification. In Fig. 5, the upper limit value is SOC 100% and the lower limit value is SOC 10%.

[0059] In the limit value setting process, limit value setting unit 26 sets the discharge limit value to a value 5% higher than the lower limit value (SOC 15%), while setting the charge limit value to the upper limit value (SOC 100%). At the time of the first charge / discharge operation after the connection process, charge / discharge control unit 27 controls power conversion unit 22 so that power conversion unit 22 performs charge / discharge operation in the charge / discharge band from the discharge limit value to the upper limit value (SOC 15% to 100%).

[0060] When the SOC of the in-vehicle battery 71 reaches the charge limit value (=upper limit value) at time t1, the communication unit 24 receives a stop signal from the vehicle control unit 73. When the communication unit 24 receives the stop signal, the charge / discharge control unit 27 stops the charge / discharge operation of the power conversion unit 22 and performs a parallel-off operation. The limit value setting unit 26 changes the charge limit value to a value 5% smaller than the upper limit value (95%). Note that if the stop signal is received before the upper limit value is reached, the charge limit value may be changed in the same manner as the limit value change process in the above embodiment.

[0061] After the reconnection operation, the charge / discharge control unit 27 causes the power conversion unit 22 to resume the charge / discharge operation. The charge / discharge control unit 27 controls the power conversion unit 22 so that the power conversion unit 22 performs the charge / discharge operation in a charge / discharge band (SOC 15% to 95%) from the discharge limit value to the charge limit value.

[0062] In this modification, during the first charge / discharge operation after connection processing, the in-vehicle battery 71 can be charged until the SOC of the in-vehicle battery 71 reaches an upper limit, that is, until the in-vehicle battery 71 is fully charged. This makes it possible to maximize the charging capacity of the in-vehicle battery 71. The greater the total battery capacity value of the in-vehicle battery 71, the greater the benefit of this modification.

[0063] In this modification, if the default value of the charge limit value is SOC 100%, the charge limit value may be left as the default value without being set in the limit value setting process. Also, even if the charge limit value is set to a value smaller than the upper limit value in the limit value setting process, the power conversion unit 22 may be controlled so that the power conversion unit 22 performs charging and discharging operations in the charge and discharge band from the discharge limit value to the upper limit value only during the first charging operation after the connection process.

[0064] [Other variations] The charging / discharging device of the present invention may be configured to include a vehicle connection unit configured to be connectable to an electric vehicle, a power conversion unit that performs charging and discharging operations on the onboard battery of the electric vehicle via the vehicle connection unit, and a control unit that controls the charging and discharging operations of the power conversion unit.

[0065] The control unit of the present invention can be configured as appropriate as long as it executes a connection process for connecting the vehicle connection unit to the electric vehicle, a charge / discharge start process for causing the power conversion unit to start a charging or discharging operation, an information acquisition process for acquiring battery information relating to the upper and lower limit values of the SOC of the onboard battery from the electric vehicle between the connection process and the charge / discharge start process, and a limit value setting process for setting the discharge limit value during a discharging operation to a value greater than the lower limit value between the information acquisition process and the charge / discharge start process.

[0066] In the limit value setting process, the control unit of the present invention may set the charge limit value to an upper limit value as in the above-described modified example, or may set the charge limit value to a value smaller than the upper limit value as in the above-described embodiment. The extent to which the charge limit value is to be smaller than the upper limit value and the extent to which the discharge limit value is to be larger than the lower limit value are preferably set according to the total battery capacity value of the in-vehicle battery 71, etc. The closer the charge / discharge limit value is to the upper or lower limit value, the wider the charge / discharge band can be. However, depending on the accuracy of the SOC value detected by the vehicle control unit 73, the charge / discharge limit value and the upper or lower limit value may overlap, which may result in the transmission of a stop signal.

[0067] The power conditioner device of the present invention may not be equipped with a storage battery 30, may be equipped with another power generation device in addition to the solar power generation device 40, or may be equipped with another power generation device instead of the solar power generation device 40. [Explanation of symbols]

[0068] 1. Charging and discharging system 10 Power conditioner device 11 First converter section 12 Second converter section 13 Inverter section 14 Power conditioner control unit 20 Charge / discharge device 21 Vehicle connection 22 Power conversion section 23 Control Unit 24 Communications Department 25 Memory section 26 Limit value setting section 27 Charge / discharge control unit 30 Storage battery 40 Solar power generation equipment 50 load 60 Power system 70 Electric vehicle 71 Automotive battery 72 Contactor 73 Vehicle control unit

Claims

1. a vehicle connection unit configured to be connectable to an electric vehicle; a power conversion unit that performs charging and discharging operations on an on-board battery of the electric vehicle via the vehicle connection unit; a control unit that controls the charging operation and the discharging operation of the power conversion unit; A charging / discharging device comprising: The control unit a connection process for performing a connection operation between the vehicle connection unit and the electric vehicle; a charge / discharge start process for causing the power conversion unit to start the charging operation or the discharging operation; an information acquisition process, performed between the connection process and the charge / discharge start process, for acquiring battery information relating to an upper limit value and a lower limit value of an SOC of the on-board battery from the electric vehicle; a limit value setting process for setting a discharge limit value during the discharging operation to a value greater than the lower limit value between the information acquisition process and the charge / discharge start process; the power conversion unit performs the charging operation and the discharging operation in a charging / discharging band equal to or greater than the discharge limit value, When the control unit sets the charge limit value during the charging operation to a value smaller than the upper limit value between the information acquisition process and the charge / discharge start process as the limit value setting process, the control unit causes the power conversion unit to perform the charging operation in the charge / discharge band from the discharge limit value to the upper limit value only during the first charging operation after the connection process. A charging / discharging device characterized by:

2. When the control unit acquires a total battery capacity value of the in-vehicle battery without acquiring an SOC value corresponding to the upper limit value as the battery information, the control unit converts the total battery capacity value into an SOC value of the in-vehicle battery and sets the SOC value as the upper limit value.

2. The charging / discharging device according to claim 1.

3. when the control unit receives a stop signal from the electric vehicle during the charging operation or the discharging operation to stop the charging operation or the discharging operation, the control unit executes a limit value change process to change at least one of the charging limit value or the discharging limit value to narrow the charging / discharging band; The power conversion unit performs the charging operation and the discharging operation in the changed charging / discharging band.

3. The charging / discharging device according to claim 1 or 2.

4. A charge / discharge system including the charge / discharge device according to any one of claims 1 to 3 and a power conditioner device, The power conditioner device is connected to the charging / discharging device, the power generation device, and a load, and performs an operation of supplying power generated by the power generation device to the charging / discharging device, and an operation of converting DC power input from the charging / discharging device into AC power and supplying the AC power to the load. A charging and discharging system characterized by the above.

5. further comprising a storage battery; The power conditioner device performs an operation of charging the storage battery and an operation of discharging the storage battery.

5. The charging / discharging system according to claim 4.

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