Electrical fault detection device and vehicle power supply system

Patent metadata

Field	Value
Publication number	US-2022011377-A1
Application number	US-201917428013-A
Country	US
Kind code	A1
Filing date	Dec 9, 2019
Priority date	Feb 19, 2019
Publication date	Jan 13, 2022
Grant date	—

Abstract

In first coupling capacitor, a first terminal is connected to a first connection point on a current path of power storage in a state of being insulated from a ground. Second coupling capacitor has a second terminal connected to a second connection point that is on a current path of power storage and is lower in potential than the first connection point, and second coupling capacitor has a first terminal connected to a second terminal of first coupling capacitor. AC output unit applies a predetermined AC voltage via impedance element to third connection point between the second terminal of first coupling capacitor and the first terminal of second coupling capacitor. Voltage measurement unit measures a voltage at third connection point. Determination unit determines the presence or absence of an electrical fault on the basis of the voltage measured by voltage measurement unit.

First claim

1 . An electrical fault detection device comprising:
a first coupling capacitor including one cell or a plurality of cells connected in series, and including a first terminal connected to a first connection point on a current path of a power storage, the power storage being in a state of being insulated from a ground; a second coupling capacitor including a second terminal connected to a second connection point on a current path of the power storage, the second connection point being lower in potential than the first connection point, the second coupling capacitor including a first terminal connected to a second terminal of the first coupling capacitor; an alternating (AC) current output unit configured to apply a predetermined AC voltage via an impedance element to a third connection point between the second terminal of the first coupling capacitor and the first terminal of the second coupling capacitor; a voltage measurement unit configured to measure a voltage at the third connection point; and a determination unit configured to determine whether or not the current is leaked, based on a voltage measured by the voltage measurement unit.

2 . The electrical fault detection device according to claim 1 , wherein
the first coupling capacitor and the second coupling capacitor are aluminum electrolytic capacitors, each first terminal of the first coupling capacitor and the second coupling capacitor is a positive electrode terminal, and each second terminal of the first coupling capacitor and the second coupling capacitor is a negative electrode terminal.

3 . The electrical fault detection device according to claim 1 , wherein
the first connection point is a positive electrode of the power storage, and the second connection point is a negative electrode of the power storage.

4 . A vehicle power supply system comprising:
a power storage mounted in a state of being insulated from a chassis ground of a vehicle, the power storage being configured to supply power to a load in the vehicle; a first switch to be inserted in positive wiring connected with a positive electrode of the power storage and one end of the load; a second switch to be inserted in negative wiring connected with a negative electrode of the power storage and another end of the load; and the electrical fault detection device according to claim 1 .

Assignees

• Sanyo Electric Co

Inventors

• Nakayama Masato
• Kunimitsu Tomonori

Classifications

• H02H3/05

  with means for increasing reliability, e.g. redundancy arrangements {(for logic circuits H03K19/003)} · CPC title

• H02H3/17

  by means of an auxiliary voltage injected into the installation to be protected {(using summation current transformers H02H3/33)} · CPC title

• B60L3/0046

  relating to electric energy storage systems, e.g. batteries or capacitors · CPC title

• B60L3/0069

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

• G01R31/52 Primary

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