Error detection device

Patent metadata

Field	Value
Publication number	US-10114064-B2
Application number	US-201515516425-A
Country	US
Kind code	B2
Filing date	Oct 23, 2015
Priority date	Oct 31, 2014
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

An abnormality detection device includes: a coupling-capacitor having a first-end and a second-end coupled with a high-voltage circuit; a signal output unit; a signal extraction unit; and a signal input unit. The signal output unit is coupled with the first-end of the coupling-capacitor via a detection-resistor, and outputs an alternating-current inspection-signal. The signal extraction unit extracts the inspection-signal, as an extraction-signal, output between the detection-resistor and the coupling-capacitor. The signal input unit detects abnormality of insulation resistance of the high-voltage circuit based on a level of the inputted extraction-signal. The signal extraction unit includes a signal removing filter and a subtraction circuit. The filter removes a signal equal in frequency to the inspection-signal and passes low-frequency noises lower in frequency than the inspection-signal. The subtraction circuit outputs a differential signal, as the extraction-signal, between a signal having passed through the filter and a signal not having passed through the filter.

First claim

What is claimed is:

1. An abnormality detection device comprising:
a coupling capacitor including:
a first end; and
a second end to be coupled with a high-voltage circuit;

a signal output unit which outputs an alternating-current inspection signal, the signal output unit being coupled with the first end of the coupling capacitor via a detection resistor;
a signal extraction unit which extracts the inspection signal as an extraction signal, the inspection signal being output between the detection resistor and the coupling capacitor; and
a signal input unit which receives the extraction signal and detects an abnormality of insulation resistance of the high-voltage circuit based on a level of the received extraction signal,
wherein the signal extraction unit includes:
a signal removing filter which removes a signal equal in frequency to the inspection signal, and passes, through the signal removing filter, a low-frequency noise lower in frequency than the inspection signal; and
a subtraction circuit which outputs a differential signal as the extraction signal, the differential signal being a difference between a signal having been passed through the signal removing filter and a signal not having been passed through the signal removing filter, and

wherein the signal removing filter is a low-pass filter which removes the signal equal in frequency to the inspection signal and passes the low-frequency noise through the signal removing filter.

2. The abnormality detection device according to claim 1 ,
wherein the signal extraction unit further includes a noise removing filter which removes a high-frequency noise higher in frequency than the inspection signal and passes, through the noise removing filter, the low-frequency noise and the signal equal in frequency to the inspection signal, and
the subtraction circuit outputs a differential signal as the extraction signal, the differential signal being a difference between the signal having been passed through the signal removing filter, and a signal that having been passed through the noise removing filter but having not been passed through the signal removing filter.

3. An abnormality detection device comprising:
a coupling capacitor including:
a first end; and
a second end to be coupled with a high-voltage circuit;

a signal output unit which outputs an alternating-current inspection signal, the signal output unit being coupled with the first end of the coupling capacitor via a detection resistor;
a signal extraction unit which extracts the inspection signal as an extraction signal, the inspection signal being output between the detection resistor and the coupling capacitor; and
a signal input unit which receives the extraction signal and detects an abnormality of insulation resistance of the high-voltage circuit based on a level of the received extraction signal,
wherein the signal extraction unit includes:
a signal removing filter which removes a signal equal in frequency to the inspection signal, and passes, through the signal removing filter, a low-frequency noise lower in frequency than the inspection signal; and
a subtraction circuit which outputs a differential signal as the extraction signal, the differential signal being a difference between a signal having been passed through the signal removing filter and a signal not having been passed through the signal removing filter,

wherein the signal extraction unit further includes a noise removing filter which removes a high-frequency noise higher in frequency than the inspection signal and passes, through the noise removing filter, the low-frequency noise and the signal equal in frequency to the inspection signal, and
wherein the subtraction circuit outputs a differential signal as the extraction signal, the differential signal being a difference between the signal having been passed through the signal removing filter, and a signal that having been passed through the noise removing filter but having not been passed through the signal removing filter.

4. The abnormality detection device according to claim 3 , wherein the noise removing filter is a low-pass filter which removes the high-frequency noise higher in frequency than the inspection signal and passes, through the noise removing filter, the low-frequency noise and the signal equal in frequency to the inspection signal.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Hashimoto Daichi
• Nakazawa Takashi
• Sekino Haruhiko

Classifications

• G01R31/52

  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

• H04B3/56

  Circuits for coupling, blocking, or by-passing of signals · CPC title

• G01R1/00

  Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00 (constructional details particular to {electromechanical} arrangements for measuring the electric consumption G01R11/02) · CPC title

• G01R31/006

  on road vehicles, e.g. automobiles or trucks (testing of ignition installations peculiar to internal combustion engines F02P17/00) · CPC title