Partial discharge sensor

• US 9,383,402 B2
• Filed: 02/21/2012
• Issued: 07/05/2016
• Est. Priority Date: 02/21/2012
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Fukasawa, Toru, Ito, Takashi, Miyashita, Hiroaki
• Primary Examiner(s): Nguyen, Vincent Q
• Application Number:
  US14/371,394
• Publication Number:
  US 20150204936A1
• Time in Patent Office: 1,596 Days
• Field of Search: 324/536, 324/551
• US Class Current: 1/1
• CPC Class Codes: 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
• CPC Class Codes: G01R 31/1272 of cable, line or wire insulation, e.g. using partial discharge measurements locating faults in cables G01R31/083
• CPC Class Codes: G01R 31/1281 of liquids or gases
• CPC Class Codes: G01R 31/14 Circuits therefor , e.g. for generating test voltages, sensing circuits G01R31/1209 - G01R31/1227 take precedence; for testing switches G01R31/327
• CPC Class Codes: G01R 31/327 Testing of circuit interrupters, switches or circuit-breakers
• CPC Class Codes: H01Q 9/28 Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines waveguide horns or mouths H01Q13/00; slot antennas H01Q13/00
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407
• CPC Class Codes: H02B 13/065 Means for detecting or reacting to mechanical or electrical defects

Abstract

A partial discharge sensor is configured to have a metal casing 7 disposed outside flange 2a and 2b and a bowtie antenna 8 disposed inside the metal casing 7 in a direction orthogonal to a circumferential direction of the flanges 2a and 2b to thus receive a signal caused by a partial discharge over a wide band with high sensitivity.

Claims

1. A partial discharge sensor detecting a partial discharge that occurs in high power equipment provided with:

a first conductor tube having a first flange formed on an end portion thereof;

a second conductor tube having a second flange formed on an end portion thereof;

an insulating spacer that is sandwiched between the first and the second flanges, and holds a high-voltage cable inside the first and the second conductor tubes;

a plurality of connection bolts that connect the first and the second flanges with each other,

the partial discharge sensor comprising;

a metal casing disposed on an outer side of the first and the second flanges, having a longitudinal direction in a circumferential direction of the first and the second flanges and also a width direction in a thickness direction of the insulating spacer, and having one surface opened on the side of the first and the second flanges; and

a bowtie antenna disposed inside the metal casing, and disposed in a direction orthogonal to the circumferential direction of the first and the second flanges, and having an overlapping portion with the first and the second flanges, and

a strip metal plate that covers a circumference of the insulating spacer other than an opening of the metal casing,

wherein the bowtie antenna includes a first triangular conductor disposed to have a base facing one side of the metal casing in the longitudinal direction and a second triangular conductor disposed to have a base facing the other side of the metal casing in the longitudinal direction.

2. The partial discharge sensor according to claim 1, wherein the bowtie antenna includes:

a first stripline that has one end connected to a vertex of the first triangular conductor and the other end connected to a signal part of a connector disposed in the metal casing; and

a second stripline that has one end connected to a vertex of the second triangular conductor and the other end connected to a ground part of the connector.

3. The partial discharge sensor according to claim 2, wherein in the bowtie antenna, a protruding conductor is disposed on both ends of the base of the first triangular conductor and on both ends of the base of the second triangular conductor.

4. The partial discharge sensor according to claim 2, wherein the bowtie antenna further comprises a short-circuiting line that has an electrical length that is a quarter wavelength at a frequency within a frequency band to be used and connects the first and second triangular conductors with each other.

5. The partial discharge sensor according to claim 1, wherein the metal casing is held on the outer side of the first and second flanges by the strip metal plate.

6. A partial discharge sensor detecting a partial discharge that occurs in high power equipment provided with:

a first conductor tube having a first flange formed on an end portion thereof;

a second conductor tube having a second flange formed on an end portion thereof;

an insulating spacer that is sandwiched between the first and the second flanges, and holds a high-voltage cable inside the first and the second conductor tubes;

a plurality of connection bolts that connect the first and the second flanges with each other,

the partial discharge sensor comprising;

a metal casing disposed on an outer side of the first and the second flanges, having a longitudinal direction in a circumferential direction of the first and the second flanges and also a width direction in a thickness direction of the insulating spacer, and having one surface opened on the side of the first and the second flanges; and

a bowtie antenna disposed inside the metal casing, and disposed in a direction orthogonal to the circumferential direction of the first and the second flanges,

wherein a length of the metal casing in the width direction corresponds to a length that is a sum of thicknesses of the first and second flanges and the insulating spacer, and

a strip metal plate that covers a circumference of the insulating spacer other than an opening of the metal casing,

wherein the bowtie antenna includes a first triangular conductor disposed to have a base facing one side of the metal casing in the longitudinal direction and a second triangular conductor disposed to have a base facing the other side of the metal casing in the longitudinal direction.

7. A partial discharge sensor detecting a partial discharge that occurs in high power equipment provided with:

a first conductor tube having a first flange formed on an end portion thereof;

a second conductor tube having a second flange formed on an end portion thereof;

an insulating spacer that is sandwiched between the first and the second flanges, and holds a high-voltage cable inside the first and the second conductor tubes;

a plurality of connection bolts that connect the first and the second flanges with each other,

the partial discharge sensor comprising;

a metal casing disposed on an outer side of the first and the second flanges, having a longitudinal direction in a circumferential direction of the first and the second flanges and also a width direction in a thickness direction of the insulating spacer, and having one surface opened on the side of the first and the second flanges; and

a bowtie antenna disposed inside the metal casing, and disposed in a direction orthogonal to the circumferential direction of the first and the second flanges, and formed on a dielectric substrate, and

a strip metal plate that covers a circumference of the insulating spacer other than an opening of the metal casing,

wherein the bowtie antenna includes a first triangular conductor disposed to have a base facing one side of the metal casing in the longitudinal direction and a second triangular conductor disposed to have a base facing the other side of the metal casing in the longitudinal direction.

8. A partial discharge sensor detecting a partial discharge that occurs in high power equipment provided with:

a first conductor tube having a first flange formed on an end portion thereof;

a second conductor tube having a second flange formed on an end portion thereof;

an insulating spacer that is sandwiched between the first and the second flanges, and holds a high-voltage cable inside the first and the second conductor tubes;

a plurality of connection bolts that connect the first and the second flanges with each other,

the partial discharge sensor comprising;

a metal casing disposed on an outer side of the first and the second flanges, having a longitudinal direction in a circumferential direction of the first and the second flanges and also a width direction in a thickness direction of the insulating spacer, and having one surface opened on the side of the first and the second flanges; and

a bowtie antenna disposed inside the metal casing, and disposed in a direction orthogonal to the circumferential direction of the first and the second flanges,

wherein a length of the metal casing in the longitudinal direction corresponds to a distance between the connection bolts in the first and second flanges, and

a strip metal plate that covers a circumference of the insulating spacer other than an opening of the metal casing,

wherein the bowtie antenna includes a first triangular conductor disposed to have a base facing one side of the metal casing in the longitudinal direction and a second triangular conductor disposed to have a base facing the other side of the metal casing in the longitudinal direction.