Protection circuit for in-vehicle battery

Patent metadata

Field	Value
Publication number	US-2019386350-A1
Application number	US-201816487150-A
Country	US
Kind code	A1
Filing date	Feb 14, 2018
Priority date	Mar 7, 2017
Publication date	Dec 19, 2019
Grant date	—

Abstract

A protection circuit of an in-vehicle battery has a detection unit that detects at least the temperature of the in-vehicle battery, and a control unit that controls a first relay and a second relay. The control unit performs a first switching control when either the temperature or the output current of the in-vehicle battery detected by the detection unit is in a first abnormality range in a case where the first relay is on and the second relay is off, and performs a second switching control when the temperature of the in-vehicle battery detected by the detection unit is within the first abnormality range or within the second abnormality range after the first switching control.

First claim

1 . A protection circuit for an in-vehicle battery, comprising:
a first relay that is positioned on a first conduction path that is a path for supplying power from the in-vehicle battery to an external circuit, the first relay being configured to switch on or off the supply of power from the in-vehicle battery to the external circuit; a discharge circuit that includes a second relay and a resistor unit that are connected in series on a path that is different from the first conduction path, the discharge circuit being configured to allow current from the in-vehicle battery to flow via the resistor unit when the second relay is in an on state; a detection unit configured to detect at least one of a temperature of the in-vehicle battery and an output current from the in-vehicle battery; and a control unit configured to, when at least one of the temperature and the output current detected by the detection unit is within a first abnormality range in a case where the first relay is in the on state and the second relay is in an off state, perform a first switching control for switching the first relay to the off state while keeping the second relay in the off state, and, when the temperature of the in-vehicle battery detected by the detection unit is within the first abnormality range or a second abnormality range after the first switching control, perform a second switching control for switching the second relay to the on state while keeping the first relay in the off state.

2 . The protection circuit for an in-vehicle battery according to claim 1 , wherein the detection unit includes a current detection unit configured to detect the output current from the in-vehicle battery, and a temperature detection unit configured to detect the temperature of the in-vehicle battery, and
the control unit is configured to, when the output current of the in-vehicle battery detected by the current detection unit is within the first abnormality range in a case where the first relay is in the on state and the second relay is in the off state, perform the first switching control, and, when the temperature of the in-vehicle battery detected by the temperature detection unit is within the second abnormality range after the first switching control, perform the second switching control.

3 . The protection circuit for an in-vehicle battery according to claim 1 , wherein the detection unit includes a temperature detection unit configured to detect the temperature of the in-vehicle battery, and
when the temperature of the in-vehicle battery detected by the temperature detection unit is within the first abnormality range in a case where the first relay is in the on state and the second relay is in the off state, the control unit performs the first switching control, and when the temperature of the in-vehicle battery detected by the temperature detection unit is within the first abnormality range or within the second abnormality range after the first switching control, the control unit performs the second switching control.

4 . The protection circuit for an in-vehicle battery according to claim 3 , wherein the first abnormality range is a range of being greater than or equal to a predetermined first temperature, and the second abnormality range is a range of being greater than or equal to a second temperature that is greater than the first temperature.

Assignees

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

Inventors

• Sato Shinichiro

Classifications

• B60L2240/549

  Current · CPC title

• B60L2240/545

  Temperature · CPC title

• B60L3/0046

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

• B60L3/04

  Cutting off the power supply under fault conditions (protective devices and circuit arrangements in general H01H; H02H) · CPC title

• B60L58/24

  for controlling the temperature of batteries · CPC title