Dynamic balance anti-interference device of cable partial discharge and working method of dynamic balance anti-interference device

Abstract

The invention provides a dynamic balance anti-interference device of cable partial discharge and a working method of the dynamic balance anti-interference device and relates to the field of measurement of the cable partial discharge. The cost and accuracy of traditional measurement of cable partial discharge failures cannot be both considered. According to the dynamic balance anti-interference device, a voltage regulator is connected with a power supply; an exciting transformer is connected with the voltage regulator; a high electric potential end of the exciting transformer is sequentially connected with an electric reactor and a high-voltage filter in series; a dynamic balance impedor is connected with a partial discharge detector; a grounding end of the dynamic balance impedor and a low electric potential end of the exciting transformer are connected with a common ground GND; a coupling capacitor wiring end of the dynamic balance impedor and a wiring end of a detected cable are connected with low electric potential ends of a partial-discharge-free coupling capacitor Ck and the detected cable Cx respectively; an output HV end of the high-voltage filter is connected with high electric potential ends of the partial-discharge-free coupling capacitor Ck and the detected cable Cx in parallel. According to the dynamic balance anti-interference device of the cable partial discharge, the testing cost is effectively reduced, a plurality of types of interferences are eliminated and a testing result is more accurate.

Description

technical field [0001] The invention relates to the field of cable partial discharge measurement, in particular to a cable partial discharge dynamic balance anti-interference device and a working method thereof. Background technique [0002] Cables play the role of transmitting electric energy in the power system. If continuous partial discharge occurs in the insulation structure of the cable for a long time, the insulation and dielectric properties may be seriously damaged. If the partial discharge fault has not been discovered and dealt with, it may eventually lead to disaster. sexual failure. Therefore, it is very important to detect the partial discharge of the cable and find its insulation fault in time. [0003] In traditional measurement, different anti-interference measures need to be taken for different types of interference, such as: using isolation transformers to reduce power interference; grounding the entire system at a single point to reduce ground interferen...

AI Technical Summary

Problems solved by technology

The use of isolation transformers and shielding laboratories will undoubtedly increase the test cost; if the single-point grounding is not handled properly, grounding interference is still unavoidable; due to the extremely high requirements for the coupling capacitance in the balance measurement method, when the matching degree of the coupling capacitance and the test object When it is not high, the interference cannot be completely suppressed. In addition, the measurement results of this method directly weaken the common-mode interference, and finally the type of this part of the interference cannot be known; the pulse discrimination method is due to the different paths of the two signals and the influence of other interference The waveform of the channel signal may be distorted and there is a time delay, which makes the method invalid and it is difficult to suppress external discharge interference

Images