Pulse wave velocity correction method for partial discharge monitoring of high-voltage cable

Abstract

The invention discloses a pulse wave velocity correction method for partial discharge monitoring of a high-voltage cable, and the method comprises the steps: firstly injecting a coupling pulse into agrounding connector of a three-phase cable in a current grounding box based on electromagnetic coupling, and then collecting the coupling pulse at the grounding connector of the three-phase cable in an adjacent grounding box of the current grounding box; calculating the pulse wave velocity according to the length of the cable and the coupling pulse transmission time, fitting the load of the three-phase cable and the coefficient of the pulse wave velocity to the wave velocity load curve, and finally correcting the pulse wave velocity under the real-time load through the fitted wave velocity load curve to obtain the corrected pulse wave velocity. The correction pulse wave velocity is used for partial discharge positioning, so that the positioning result is more accurate. The pulse wave velocity can be accurately corrected according to load fluctuation, and accurate positioning of the partial discharge position is facilitated.

Description

technical field [0001] The invention relates to the technical field of cable insulation detection, in particular to a pulse wave velocity correction method for partial discharge monitoring of high-voltage cables. Background technique [0002] High-voltage cable partial discharge monitoring is of great significance for the early detection of cable insulation defects. At present, high-voltage cable partial discharge monitoring usually installs a high-frequency current transformer (HFCT) at the cross-connection grounding box to collect partial discharge signals, and conducts different signals through optical fibers. Time base synchronization of acquisition points. [0003] The accuracy of locating cable defects through partial discharge is very dependent on the propagation speed of the discharge signal in the cable. At present, the pulse wave velocity cannot be accurately obtained in cable partial discharge monitoring, and 172m / μs is often used for related calculations. Howeve...

AI Technical Summary

Problems solved by technology

[0003] The accuracy of locating cable defects through partial discharge is very dependent on the propagation speed of the discharge signal in the cable. At present, the pulse wave velocity cannot be accurately obtained in cable partial discharge monitoring, and 172m / μs is often used for related calculations.

However, the wave velocity of the pulse in the cable is affected by the temperature of the medium, so the wave velocity is often different at different times due to the load fluctuation of the cable.

Images