Method and a device for detecting an internal arc in a metal-clad electrical link

• US 20020166397A1
• Filed: 07/01/2002
• Published: 11/14/2002
• Est. Priority Date: 11/25/1998
• Status: Active Grant

• Current Assignee: Alstom Holdings (Alstom SA)
• Original Assignee: Alstom Holdings (Alstom SA)
• Inventors: Marmonier, Jean
• Granted Patent: US 6,581,462 B2
• Time in Patent Office: Days
• US Class Current: 73/865.9
• CPC Class Codes: G01L 19/0007 Fluidic connecting means
• CPC Class Codes: G01R 31/08 Locating faults in cables, transmission lines, or networks
• CPC Class Codes: G01R 31/1209 using acoustic measurements acoustic measurements G01H3/00

Abstract

The invention relates to a method of detecting an internal arc in a metal-clad electrical link, wherein the rising edge of the internal pressure surge generated by the arc and propagating inside the cladding is detected at a fixed location along the cladding. The invention also relates to a device comprising at least one one-way detection unit constituted by a pressure sensor disposed outside the cladding and connected to the inside the cladding via a horn-shaped duct which slopes relative to the axis of the cladding, which has its mouth opening out in the cladding, and which has its tip connected to the pressure sensor.

Claims

1. / A method of detecting an internal arc in a metal-clad electrical link, wherein the rising edge of the internal pressure Surge generated by the arc and propagating inside the cladding is detected at a fixed location along the cladding.

2. / A method according to claim 1, wherein the pressure inside the cladding is measured continuously for two equal durations shorter than the time taken by the rising edge to go past, and separated by a time interval shorter than the time taken by the rising edge to go past, the curve of the measurements taken during each of said durations is integrated, the difference between the two integration values is determined, and the pressure difference obtained is compared with a threshold value.

3. / A method according to claim 2, wherein the measurement durations are substantially equal to one half of the time taken by the rising edge to go past.

4. / A method according to claim 3, wherein the time interval is substantially equal to one half of the time taken for the rising edge to go past.

5. / A method according to claim 1, wherein the detection is performed Substantially in the middle of the cladding segment to be monitored.

6. / A device for implementing the method according to claim 1, the device comprising at least one one-way detection unit constituted by a pressure sensor disposed outside the cladding and connected to the inside the cladding via a horn-shaped duct which slopes relative to the axis of the cladding, which has its mouth opening out in the cladding, and which has its tip connected to the pressure sensor.

7. / A device according to claim 6, comprising a set of at least two one-way detection units having the same detection direction and disposed in the vicinity of each other, and whose ducts slope the same way.

8. / A device according to claim 7, comprising two one-way detection sets whose ducts slope in mutually opposite directions and which are disposed in the vicinity of each other.

9. / A device according to claim 6, comprising two pressure sensors connected in parallel to two ducts which slope in mutually opposite directions and whose tips communicate with each other.

10. / A device according to claim 6, comprising two directional detection units whose ducts slope in mutually opposite directions.