Locating of partial-discharge-generating faults

• US 10,209,290 B2
• Filed: 12/30/2010
• Issued: 02/19/2019
• Est. Priority Date: 12/30/2010
• Status: Active Grant

• Current Assignee: Prysmian SPA
• Original Assignee: Prysmian SPA
• Inventors: Sales Casals, Lluis-Ramon, Franchi Bononi, Stefano, Candela, Roberto, Gonzalez, Manuel Lopez
• Primary Examiner(s): Astacio-Oquendo, Giovanni
• Assistant Examiner(s): Fortich, Alvaro
• Application Number:
  US13/977,280
• Publication Number:
  US 20140002098A1
• Time in Patent Office: 2,973 Days
• CPC Class Codes: G01R 31/08 Locating faults in cables, transmission lines, or networks
• CPC Class Codes: G01R 31/086 in power transmission or distribution networks, i.e. with interconnected conductors
• 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: Y04S 10/52 Outage or fault management, e.g. fault detection or location

Abstract

A method of locating incipient faults that generate partial discharges in an AC power distribution system includes detecting at least one spike in a PD pattern generated by such system; getting the voltage wave of the AC power in the system; detecting a phase of such spike with respect to the voltage of the AC power; and locating an incipient fault where such phase is below a predetermined threshold. An apparatus includes at least one sensor of electrical pulses, means for getting a synchronism signal with a power supply of the power distribution system, and modules adapted to carry out the method.

Claims

1. A method of locating incipient faults that generate partial discharges in an AC power distribution system, comprising:

collecting a partial discharge pattern at a position of the AC power distribution system through an electric apparatus, the electric apparatus comprising at least one sensor of electrical pulses;

detecting at least one spike in the partial discharge pattern generated by such system, the at least one spike including a concentration of electrical pulses;

getting a voltage wave of AC power in the system;

detecting a phase of the spike with respect to voltage of the AC power;

locating an incipient fault at the position of the AC power distribution system if the detected phase of the spike with respect to voltage of the AC power is below a predetermined threshold; and

inspecting, repairing, or substituting only a portion of the AC power distribution system at the position when the detected phase of the spike is below the predetermined threshold.

2. The method according to claim 1, wherein the predetermined threshold is less than or equal to 10°

.

3. The method according to claim 2, wherein the predetermined threshold is less than or equal to 5°

.

4. The method according to claim 1, wherein an incipient fault is located in a power distribution system portion of length shorter than 2.5 m.

5. The method according to claim 4, wherein an incipient fault is located in a power distribution system portion of length shorter than 1 m.

6. The method according to claim 1, comprising selecting a starting detecting position and selecting at least one subsequent detecting position in a first direction along the power distribution system, as long as the phase decreases;

and selecting at least one subsequent second detecting position in a second direction opposite the first direction, if the phase increases.

7. The method according to claim 6, comprising decreasing a distance between consecutive positions as the phase decreases.

8. The method according to claim 6, comprising decreasing a distance between consecutive positions when a direction along with successive positions succeed each other is inverted.

9. The method according to claim 1, comprising a preliminary step of coarsely locating the incipient fault in a portion of the power distribution system by a conventional technique.

10. The method according to claim 1, comprising providing a plurality of partial discharge patterns, comprising detecting electrical pulses possibly representative of partial discharges in each detection position.

11. The method according to claim 10, wherein detecting electrical pulses lasts for a time selected runtime of 10 to 60 seconds.

12. The method according to claim 11, wherein detecting electrical pulses lasts for a time selected runtime of 15 to 30 seconds.