# US 7,746,082 B2 · Partial discharge detection device

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- Number: US 7,746,082 B2
- Document ID: US7746082B2
- Status: Granted
- Kind: B2
- Application number: 11/949,585
- Filed: 2007-12-03
- Published: 2009-01-29
- Granted: 2010-06-29
- Earliest claimed: 2006-12-04
- Assignees: Kabushiki Kaisha Toshiba
- Inventors: Shiro Maruyama; Takaaki Sakakibara; Toshihiro Hoshino
- Web page: https://patentgrep.com/patent/US7746082B2

## CPC

- G01R 31/1254: {of gas-insulated power appliances or vacuum gaps (testing switches G01R31/327; detecting electrical or mechanical defects in encased switchgear H02B13/065)}
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)

## Abstract

The present invention provides a high-performance partial discharge detection device which is user-friendly and compact and which allows detection of the electromagnetic waves caused by partial discharge, over a wide bandwidth with a simple constitution and a favorable S/N ratio. The waveguide antenna which receives electromagnetic waves that leak from the insulating spacer is attached to the outer circumferential face of the insulating spacer. The waveguide antenna is constituted by a waveguide portion and a coaxial cable connector which is installed on the waveguide portion. The waveguide portion has a metal short-circuit plate provided at one end thereof, and an opening formed at the other end thereof, which covers part of the outer circumferential face of the insulating spacer.

## Claims

### Claim 1

A partial discharge detection device which is used in a gas-insulated equipment in which a high voltage conductor is supported by an insulator inside a hermetically sealed metal container charged with an insulating gas, and which detects partial discharge in the gas-insulated equipment, comprising:
receiving means for receiving electromagnetic waves which leak from the insulator;
signal processing means for signal-processing the electromagnetic waves received by the receiving means; and
signal processing determination means for determining, from the value of a signal that is signal-processed by the signal processing means, whether electromagnetic waves due to partial discharge generated inside the gas-insulated equipment are received,
wherein the receiving means comprises a waveguide portion and a coaxial cable connector that is attached to the waveguide portion;
the waveguide portion has a metal short-circuit plate at one end thereof, and an opening at the other end thereof, which is formed opposite the insulator;
a coaxial cable for measurement is attached to the coaxial cable connector and the signal processing means is connected to the coaxial cable; and
in the receiving means, the distance between the position of the coaxial cable connector and the opening of the waveguide portion is set at no more than ¼ a cut-off wavelength of the waveguide portion.

### Claim 2 (depends on 1)

The partial discharge detection device according to claim 1, wherein the opening in the waveguide portion is made to contact the outer circumference of the insulator.

### Claim 3 (depends on 1)

The partial discharge detection device according to claim 1, wherein the cutout shape of the opening in the waveguide portion of the receiving means is a circular arc.

### Claim 4 (depends on 1)

The partial discharge detection device according to claim 1, wherein the receiving means has a structure in which the distance between the position of the coaxial cable connector and the opening in the waveguide portion is variable.

### Claim 5 (depends on 1)

The partial discharge detection device according to claim 1, wherein a conductor of the coaxial cable connector of the receiving means is disposed parallel to the high voltage conductor in the gas-insulated equipment.

### Claim 6 (depends on 1)

The partial discharge detection device according to claim 1, wherein the waveguide portion of the receiving means has a slide-type multiple structure.