Charging and discharging system

Abstract

Simplify the system. [Solution] The present invention relates to a charge and discharge system that performs AC charging from the equipment side to a vehicle and AC discharging from the vehicle to the equipment side. The system includes a charging path connected to the vehicle on one end via a charging relay 26, a discharging path connected to the vehicle on one end via a discharging relay 24, and a ground fault circuit interrupter 50 provided in the path that is connected to the equipment side after the other ends of the charging and discharging paths are connected, in order to protect against ground faults.

Description

[Technical Field]

[0001] The present disclosure relates to a charging / discharging system that connects a pair of power lines carrying AC power to a vehicle and performs charging and discharging of the vehicle. [Background Art]

[0002] In electric vehicles such as electric vehicles and plug-in hybrid vehicles, an on-board secondary battery can be charged from the outside. Further, the secondary batteries mounted on these electric vehicles have a relatively large capacity, and a V2H (vehicle to home) system that supplies power from the on-board secondary battery to facilities such as residences in the event of a power outage or the like is known.

[0003] In this V2H system, a charging / discharging device (EVPS: Electric Vehicle Power Station) is provided on the residence side, which is connected to the vehicle to charge the secondary battery of the vehicle from the residence side, or supply power to the residence with the electric power from the secondary battery of the vehicle.

[0004] Patent Document 1 describes a V2H system with AC input / output on the vehicle side. [Prior Art Documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2022-146593 [Summary of the Invention] [Problem to be Solved by the Invention]

[0006] Here, in many V2H systems, for the power lines that perform charging and discharging, a charging path for charging a vehicle from the facility side and a discharging path for discharging electric power from the vehicle to the facility side are separately provided, and these are switched for use. In such a case, an earth leakage circuit breaker as a countermeasure against electric leakage in a power line has been provided for each of the charging path and the discharging path. [Means for Solving the Problem]

[0007] The charging and discharging system according to this disclosure is a charging and discharging system that performs AC charging from the equipment side to a vehicle and AC discharging from the vehicle to the equipment side, and includes a charging path connected to the vehicle on one end via a charging relay, a discharging path connected to the vehicle on one end via a discharging relay, and a ground fault circuit interrupter provided in the path that is connected to the equipment side after the other ends of the charging path and the discharging path are connected, to protect against ground faults. [Effects of the Invention]

[0008] According to the charging and discharging system described herein, only one earth leakage circuit breaker needs to be placed in a single location, simplifying the system and reducing costs. [Brief explanation of the drawing]

[0009] [Figure 1] This is a block diagram showing the configuration of a charge / discharge system according to an embodiment. [Figure 2] This is a diagram showing the configuration of a modified example. [Figure 3] This is a diagram showing the configuration of the comparative example. [Figure 4] This diagram shows an example of the configuration of a ground fault circuit interrupter. [Modes for carrying out the invention]

[0010] The embodiments of this disclosure will be described below with reference to the drawings. The embodiments described below are not limiting to this disclosure, and configurations formed by selectively combining multiple examples are also included in this disclosure.

[0011] "System Configuration" Figure 1 is a block diagram showing the configuration of a charging and discharging system according to an embodiment. System 10 is a power transmission facility of a power company, which supplies AC power such as single-phase AC 200V, three-phase AC 200V, and single-phase 100V.

[0012] System 10 is connected to electrical equipment within the facility via a distribution board installed in the facility, and power from the system is supplied to the electrical equipment within the facility. An EVPS (Electric Vehicle Power Station) 20, which is a device for charging and discharging vehicles, is connected to the distribution board.

[0013] The EVPS20 includes a PCS (Power Control Station)22. This PCS22 is a power conversion device that has AC / DC conversion and DC / AC conversion functions.

[0014] A distribution board is connected to one end of PCS22. PCS22 can convert alternating current (AC) power from the distribution board to direct current (DC) power, and then convert the resulting DC power back to AC power for output. A solar panel can also be connected to PCS22, in which case the output of the solar panel is supplied to an intermediate DC line. The other end of PCS22 is connected to a connection line 30 via a discharge relay 24.

[0015] The EVPS20 is equipped with a charging relay 26, to which a power line from the distribution board is connected. The other end of the charging relay 26 is connected to the connection line 30.

[0016] In other words, the power lines from the distribution board are branched, with one branch connected to the connection line 30 via the PCS22 and discharge relay 24, and the other branch connected to the connection line 30 via the charge relay 26. The path passing through the PCS22 and discharge relay 24 is the discharge path, and the path passing through the charge relay 26 is the charge path.

[0017] The connection line 30 is connected to the onboard charger (OBC) 40 mounted on the vehicle. The OBC 40 converts AC power supplied from the equipment side into DC power and supplies the resulting DC power to the onboard secondary battery for charging. It also converts the DC power from the onboard secondary battery into AC power and supplies it to the connection line 30. In other words, charging and discharging of the vehicle are performed via the OBC 40.

[0018] A charging / discharging earth leakage breaker 50 is provided on the distribution board side of the branch point from the distribution board to the charging relay 26 of the EVPS 20 and the PCS 22, that is, the connection point between the discharge path and the charging path.

[0019] In this example, when charging the vehicle, the discharge relay 24 is turned off and the charging relay 26 is turned on. In this state, AC power from the grid 10 side is supplied to the on-vehicle secondary battery via the OBC 40. Further, when discharging the vehicle, the discharge relay 24 is turned on and the charging relay 26 is turned off. In this state, power from the on-vehicle secondary battery is supplied to the distribution board via the discharge relay 24 and the PCS 22.

[0020] In both the current path during charging and the charging path during discharging, the charging / discharging earth leakage breaker 50 is located between the path and the grid 10. Therefore, leakage detection and power interruption can be performed by the charging / discharging earth leakage breaker 50 in both charging and discharging of the vehicle.

[0021] Figure 2 is a diagram showing the configuration of a modification. In the example of Figure 1, the discharge path and the charging path are connected inside the EVPS 20 to combine the power lines. In the example of Figure 2, the connection point between the discharge path and the charging path is located outside the EVPS 20. The charging / discharging earth leakage breaker 50 is arranged on the grid side of the connection point. According to this example, similarly to the case described above, one charging / discharging earth leakage breaker 50 can detect leakage during both charging and discharging.

[0022] Figure 3 is a diagram showing the configuration of a comparative example. As shown, a discharging earth leakage breaker 52 is arranged between the PCS 22 and the grid 10, and a charging earth leakage breaker 54 is arranged between the charging relay 26 and the grid 10. That is, after the power line from the grid 10 branches into the discharge path and the charging path at the branch point, the discharging earth leakage breaker 52 is arranged on the discharge path, and the charging earth leakage breaker 54 is arranged on the charging path.

[0023] In the system according to the present embodiment, by connecting the charging path and the discharge path and arranging the earth leakage breaker on the integrated power line, it is only necessary to arrange the earth leakage breaker at one location, and the system cost can be reduced. "Regarding leakage current detection"

[0024] Figure 4 shows an example configuration of a charge / discharge earth leakage circuit breaker 50. In this example, a zero-sequence current transformer is used as the earth leakage circuit breaker. A coil 62 is provided to surround the two power lines to be detected, and the current flowing through this coil 62 is detected. When an earth leakage occurs, the leakage current flows toward the ground at that location, causing an imbalance in the alternating current flowing through the power lines, and a zero-sequence current flows. This zero-sequence current then drives an electromagnetic coil 64, which turns off a switch 66 placed on the power line. In this way, an earth leakage can be detected and the power supply can be interrupted. [Explanation of symbols]

[0025] 10 circuits, 20 EVPS, 24 discharge relays, 26 charge relays, 30 connection lines, 50 charge / discharge earth leakage circuit breakers, 50 earth leakage circuit breakers, 52 discharge earth leakage circuit breakers, 54 charge earth leakage circuit breakers, 62 coils, 64 electromagnetic coils, 66 switches

Claims

[Claim 1] A charge / discharge system that performs AC charging from the equipment side to the vehicle and AC discharging from the vehicle to the equipment side, A charging path is connected to the vehicle on one end via a charging relay, A discharge path connected to the vehicle on one end via a discharge relay, A ground fault circuit interrupter is provided in the path that is connected to the equipment side after the other end of the charging path and the discharging path have been connected, to protect against ground faults. including, Charging and discharging system.

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