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EP-4737188-A1 - CONTROL SYSTEM FOR VEHICLE

EP4737188A1EP 4737188 A1EP4737188 A1EP 4737188A1EP-4737188-A1

Abstract

A vehicle (10) includes a battery (120) capable of charging and discharging power for traveling of the vehicle, and a BOBC (130) including a bidirectional inverter (132) that converts DC power of the battery into AC power, and outputting the converted AC power to an outside of the vehicle. An insulation resistance reduction detection unit (133) senses a reduction in insulation resistance from an AC side of the bidirectional inverter to the battery. When discharging from the BOBC to the outside is performed, a processor (1311, 111) senses a reduction in insulation resistance (S132) using the insulation resistance reduction detection unit, before connection of a relay (134, 234) that switches between a cut-off state and a connected state of an electric path connecting the AC side of the bidirectional inverter and the outside of the vehicle (S135), and, when a reduction in insulation resistance is not sensed, the processor issues a command to switch the relay to the connected state (S133 to S135, S193 to S195, S213 to S214).

Inventors

  • NAKAMURA, TOHRU

Assignees

  • TOYOTA JIDOSHA KABUSHIKI KAISHA

Dates

Publication Date
20260506
Application Date
20251008

Claims (5)

  1. A control system (131, 110) for a vehicle (10), the vehicle (10) including a power storage device (120) capable of charging and discharging power for traveling of the vehicle (10), and a discharging unit (130) including an inverter (132) for converting DC power of the power storage device into AC power, and outputting the converted AC power to an outside of the vehicle (10), the control system (131, 110) comprising: a processor (1311, 111); and a sensing unit (133) for sensing a reduction in insulation resistance from an AC side of the inverter (132) to the power storage device (120), wherein the processor (1311, 111) is configured to sense a reduction in insulation resistance (S132) using the sensing unit, when discharging from the discharging unit to the outside is performed, before connection of a relay (134, 234) configured to switch between a cut-off state and a connected state of an electric path connecting the AC side of the inverter (132) and the outside of the vehicle (10), and the processor (1311, 111) is configured to issue a command to switch the relay to the connected state when a reduction in insulation resistance is not sensed.
  2. The control system (131, 110) according to claim 1, wherein the processor (1311, 111) is configured to sense a reduction in insulation resistance, while exchanging information necessary for discharging between the discharging unit (130) and an external charging/discharging device.
  3. The control system (131, 110) according to any one of claims 1 or 2, wherein the processor (1311, 111) is configured to prohibit sensing of a reduction in insulation resistance using the sensing unit (133) after the connection of the relay (134, 234).
  4. The control system (131, 110) according to any one of claims 1 to 3, wherein the relay (134) is included in the discharging unit (130).
  5. The control system (131, 110) according to claim 1, wherein the relay (234) is provided outside the vehicle (10), and the sensing unit (133) is configured to further sense a reduction in insulation resistance from the relay (234) to the inverter (132).

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is based on Japanese Patent Application No. 2024-190336 filed on October 30, 2024 with the Japan Patent Office, the entire contents of which are hereby incorporated by reference. BACKGROUND Field The present disclosure relates to a control system for a vehicle, and more particularly, to a control system for a vehicle including a power storage device capable of charging and discharging power for traveling of the vehicle. Description of the Background Art Conventionally, in a vehicle including a power storage device capable of charging and discharging power, charging or discharging is performed in accordance with a sequence that can ensure a standby period before insulation diagnosis after communication for starting charging or discharging (see, for example, Japanese Patent Laying-Open No. 2023-091287). A vehicle in Japanese Patent Laying-Open No. 2023-091287 includes a relay that switches between opening and closing of a contact that cuts off or connects an electric path between an external device and a power storage device, and a control device that controls the relay and charging and discharging of the power storage device. The control device performs welding diagnosis for the contact after controlling the contact of the relay to be opened, determines whether or not the welding diagnosis is normally finished, and, when it determines that the welding diagnosis is not normally finished at the time of controlling the contact to be closed, the control device performs the welding diagnosis in a standby period. Thereby, when the welding diagnosis for the contact is not normally finished after the contact of the relay is controlled to be opened, the welding diagnosis is performed in the standby period before insulation diagnosis after communication for starting charging or discharging. As a result, it is possible to appropriately perform the welding diagnosis when a sequence for charging or discharging is repeated without user intervention. SUMMARY When the vehicle in Japanese Patent Laying-Open No. 2023-091287 is used for AC-V2G (Alternating Current Vehicle-To-Grid), grounding is established not on the side of the vehicle but on the side of a power grid, which has caused a problem that it is not possible to sense an electric leakage and detect a reduction in insulation resistance on the side of the vehicle. The present disclosure has been made to solve the aforementioned problem, and an object of thereof is to provide a control system for a vehicle capable of ensuring electrical safety during discharging from the vehicle to the outside. A control system according to the present disclosure is a control system for a vehicle. The vehicle includes a power storage device capable of charging and discharging power for traveling of the vehicle, and a discharging unit including an inverter that converts direct current (DC) power of the power storage device into AC power, and outputting the converted AC power to an outside of the vehicle. The control system includes a processor, and a sensing unit that senses a reduction in insulation resistance from an AC side of the inverter to the power storage device. When discharging from the discharging unit to the outside is performed, the processor senses a reduction in insulation resistance using the sensing unit, before connection of a relay that switches between a cut-off state and a connected state of an electric path connecting the AC side of the inverter and the outside of the vehicle, and, when a reduction in insulation resistance is not sensed, the processor issues a command to switch the relay to the connected state. With such a configuration, when discharging from the discharging unit of the vehicle to the outside is performed, a reduction in insulation resistance is sensed using the sensing unit that senses a reduction in insulation resistance from the AC side of the inverter to the power storage device, before connection of the relay that switches between the cut-off state and the connected state of the electric path connecting the AC side of the inverter and the outside of the vehicle, and, when a reduction in insulation resistance is not sensed, the relay is switched to the connected state. Accordingly, a reduction in insulation resistance, which is a cause of an electric leakage, is sensed before discharging from the vehicle to the outside, without adding an electric leakage sensor on the side of the vehicle. As a result, it is possible to provide a control system for a vehicle capable of ensuring electrical safety during discharging from the vehicle to the outside. The processor may sense a reduction in insulation resistance, while exchanging information necessary for discharging between the discharging unit and an external charging/discharging device. With such a configuration, it is possible to shorten a time taken until discharging can be started, as compared with a case where exchange of the information n