Ground fault detection apparatus

Patent metadata

Field	Value
Publication number	US-2025035712-A1
Application number	US-202218705318-A
Country	US
Kind code	A1
Filing date	Oct 11, 2022
Priority date	Oct 29, 2021
Publication date	Jan 30, 2025
Grant date	—

Abstract

A ground fault detection apparatus is used for an on-board system. The on-board system includes a power source unit, a power storage unit, a conductive path, and a disconnection unit. The conductive path includes a first conductive path, a second conductive path, and a third conductive path. The disconnection unit includes a first disconnection unit and a second disconnection unit. A second load is connected to one path out of the second conductive path and the third conductive path, and a third load is connected to the other path. The ground fault detection apparatus includes a detection unit (a current detection unit and a control circuit) configured to detect a ground fault on at least one of the second conductive path and the third conductive path.

First claim

1 . A ground fault detection apparatus that is used for an on-board system that includes:
a power source unit, a power storage unit that is different from the power source unit, a conductive path provided between the power source unit and the power storage unit, and loads connected to the conductive path, and a disconnection unit provided on the conductive path, wherein the disconnection unit includes a first disconnection unit provided between the power source unit and the power storage unit, and a second disconnection unit provided on the power source unit side relative to the first disconnection unit, the conductive path includes a first conductive path provided between the power storage unit and the first disconnection unit, a second conductive path provided between the first disconnection unit and the second disconnection unit, and a third conductive path provided between the second disconnection unit and the power source unit, the loads include a first load that includes an essential load, a second load that includes a power steering apparatus, and a third load that is less important than the essential load, the first load is connected to the first conductive path, the second load is connected to one path out of the second conductive path and the third conductive path, the third load is connected to the other path out of the second conductive path and the third conductive path, the first disconnection unit is switched between a first allowed state in which a current is allowed to flow from the first conductive path side to the second conductive path side and a first disconnected state where the current is stopped, the second disconnection unit is switched between a second allowed state where a current is allowed to flow from the second conductive path side to the third conductive path side and from the third conductive path side to the second conductive path side and a second disconnected state where the current is stopped, and the ground fault detection apparatus includes a detection unit configured to detect a ground fault on at least one of the second conductive path and the third conductive path.

2 . The ground fault detection apparatus according to claim 1 , further comprising
a determination unit configured to determine, when a ground fault is detected on at least one of the second conductive path and the third conductive path by the detection unit, whether the ground fault site is on the second conductive path side or the third conductive path side.

3 . The ground fault detection apparatus according to claim 2 ,
wherein the determination unit determines whether a ground fault site is on the second conductive path side or the third conductive path side, based on a voltage of at least one of the second conductive path and the third conductive path when the first disconnection unit is in the first disconnected state and the second disconnection unit is in the second disconnected state.

4 . The ground fault detection apparatus according to claim 3 , further comprising
a control unit configured to perform control so as to switch the first disconnection unit to the first disconnected state and perform control so as to switch the second disconnection unit to the second disconnected state when a ground fault is detected on at least one of the second conductive path and the third conductive path by the detection unit, the determination unit determines whether a ground fault site is on the second conductive path side or the third conductive path side, based on a voltage of at least one of the second conductive path and the third conductive path, in a state where the control unit performs control so as to switch the first disconnection unit to the first disconnected state and performs control so as to switch the second disconnection unit to the second disconnected state.

5 . The ground fault detection apparatus according to claim 2 ,
wherein the determination unit includes a current detection unit configured to detect a current flowing through at least one of the second conductive path and the third conductive path, and determines whether the ground fault site is on the second conductive path side or the third conductive path side, based on a direction of a current flowing through at least one of the second conductive path and the third conductive path.

6 . The ground fault detection apparatus according to claim 2 ,
wherein the second load is connected to the third conductive path, and the ground fault detection apparatus includes a control unit configured to perform at least one of an operation of performing control so as to switch the first disconnection unit to the first disconnected state and an operation of performing control so as to switch the second disconnection unit to the second disconnected state if it is determined by the determination unit that a ground fault site is on the third conductive path side, and perform control so as to switch the first disconnection unit to the first disconnected state and perform control so as to switch the second disconnection unit to the second disconnected state if it is determined by the determination unit that a ground fault site is on the second conductive path side.

7 . The ground fault detection apparatus according to claim 2 ,
wherein the second load is connected to the second conductive path, and the ground fault detection apparatus includes a control unit configured to perform control so as to switch the first disconnection unit to the first allowed state and perform control so as to switch the second disconnection unit to the second disconnected state if it is determined by the determination unit that a ground fault site is on the third conductive path side, and perform control so as to switch the first disconnection unit to the first disconnected state if it is determined that a ground fault site is on the second conductive path side.

8 . The ground fault detection apparatus according to claim 4 , wherein the second load is connected to the third conductive path.

9 . The ground fault detection apparatus according to claim 1 ,
wherein the second load is connected to the second conductive path.

10 . The ground fault detection apparatus according to claim 3 ,
wherein the second load is connected to the third conductive path, and the ground fault detection apparatus includes a control unit configured to perform at least one of an operation of performing control so as to switch the first disconnection unit to the first disconnected state and an operation of performing control so as to switch the second disconnection unit to the second disconnected state if it is determined by the determination unit that a ground fault site is on the third conductive path side, and perform control so as to switch the first disconnection unit to the first disconnected state and perform control so as to switch the second disconnection unit to the second disconnected state if it is determined by the determination unit that a ground fault site is on the second conductive path side.

11 . The ground fault detection apparatus according to claim 4 ,
wherein the second load is connected to the third conductive path, and the ground fault detection apparatus includes a control unit configured to perform at least one of an operation of performing control so as to switch the first disconnection unit to the first disconnected state and an operation of performing control so as to switch the second disconnection unit to the second disconnected state if it is determined by the determination unit that a ground fault site is on the third conductive path side, and perform control so as to switch the first disconnection unit to the first disconnected sta

Assignees

• Autonetworks Technologies Ltd
• Sumitomo Wiring Systems
• Sumitomo Electric Industries

Inventors

• ARIMURA Michio

Classifications

• G01R31/52 Primary

  Testing for short-circuits, leakage current or ground faults · CPC title

• B60L3/0069

  relating to the isolation, e.g. ground fault or leak current · CPC title

• B60R16/033 Primary

  characterised by the use of electrical cells or batteries (for propulsion puposes B60K1/04; supplying batteries to, or removing batteries from, vehicles B60S5/06; testing of charge state G01R31/36) · CPC title

• H02H3/16

  responsive to fault current to earth, frame or mass (with balanced or differential arrangement H02H3/26 {; monitoring earth connection H02H5/105}) · CPC title

• H02J1/00

  Circuit arrangements for DC mains or DC distribution networks · CPC title