Ultralow frequency partial discharge detection-based evaluation method and system

Abstract

The invention discloses an ultralow frequency partial discharge detection-based evaluation method and an ultralow frequency partial discharge detection-based evaluation system. The method comprises the following steps: determining a power cable on which insulation performance evaluation is required to be performed according to the new laying or operation condition of a cable line; disconnecting the section of cable line with electric equipment at the two ends and taking a safety measure; performing ultralow frequency partial discharge detection on the cable line through an ultralow frequency cable partial discharge diagnosis and positioning system; performing symmetrical analysis on a partial discharge detection result by comparing the laying conditions at a cable path and a middle joint position so as to make effective evaluation on the insulation performance of the cable line. The system comprises a testing power supply, a filter, a coupling capacitor, an impedance detector and a partial discharge detector. According to the method and the system, by performing ultralow frequency partial discharge actual measurement on the cable, the mounting quality of the cable is effectively discovered, and the insulation situation of the cable is learnt, the faults of the cable are reduced, the hidden faults of the cable line can be timely discovered, and the method and system have great significance to safe and reliable operation of a power grid.

Description

technical field [0001] The invention belongs to the technical field of power cable maintenance, and in particular relates to an evaluation method and system based on ultra-low frequency partial discharge detection. Background technique [0002] Since power cables are widely used in urban power grids, the failure rate of cables directly affects the power supply reliability of the power grid. As time goes by, the insulation aging of cables will further intensify, and the resulting grid faults will become more frequent, which will seriously Threat to the safe operation of the power grid. [0003] Long-term practice has proved that partial discharge is the main cause of power cable insulation damage. Therefore, evaluating the insulation performance of power cables through effective evaluation methods and timely discovering hidden faults are important means to ensure their reliable operation. [0004] There is a lack of methods to evaluate the insulation performance of power cab...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the embodiments of the present invention is to provide an evaluation method and system based on ultra-low frequency partial discharge detection, aiming to solve the problem of lack of methods for evaluating the insulation performance of power cables

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