CN-122017480-A - Method and system for detecting partial discharge of insulating tool in uninterrupted operation

CN122017480ACN 122017480 ACN122017480 ACN 122017480ACN-122017480-A

Abstract

The application discloses a method and a system for detecting partial discharge of an insulating tool in uninterrupted operation, and relates to the technical field of partial discharge detection. The method comprises the steps of synchronously collecting a high-frequency current detection signal and an ultrasonic detection signal of an insulating tool in a detection period, dividing the detection period into a plurality of continuous time periods containing at least one effective discharge event, respectively analyzing high-frequency current propagation stability and ultrasonic propagation stability for each time period, judging discharge propagation dominant characteristics of each time period based on two types of stability analysis results, and determining dominant discharge mechanisms in the detection period according to judging results of all time periods. The method can accurately identify the dominant mechanism of two types of discharge coexistence under a complex environment, solves the problem of criterion failure caused by signal aliasing in the traditional method, improves the stability and reliability of detection results, and provides scientific basis for use, maintenance or replacement of insulating tools.

Inventors

YANG SONG
LUO YAN
LIU JIAN
ZOU JIANGHUA
LIU JIN
TAN JIN
XIONG SHILEI
YUAN XIAOSONG

Assignees

贵州电网有限责任公司遵义供电局

Dates

Publication Date: 20260512
Application Date: 20260116

Claims (10)

1. The method for detecting the partial discharge of the insulating tool in uninterrupted power operation is characterized by comprising the following steps: In a detection period, synchronously collecting a high-frequency current detection signal and an ultrasonic detection signal on the insulating tool; dividing the detection period into a plurality of continuous time periods, wherein each time period comprises at least one effective discharge event; for each of the time periods, analyzing high-frequency current propagation stability from the high-frequency current detection signal during the time period, and analyzing ultrasonic propagation stability from the ultrasonic detection signal during the time period; for each time period, determining a discharge propagation dominant characteristic in the time period based on the corresponding high-frequency current propagation stability analysis result and the ultrasonic propagation stability analysis result, wherein the discharge propagation dominant characteristic comprises an internal partial discharge dominant characteristic, a surface discharge dominant characteristic or a composite characteristic; And determining a dominant discharge mechanism in the detection period according to the discharge propagation dominant characteristic determination results corresponding to all the time periods.
2. The method of claim 1, wherein the step of determining the position of the substrate comprises, Analyzing the high-frequency current propagation stability comprises analyzing the amplitude stability and the occurrence time concentration of discharge pulses in the high-frequency current detection signal; analyzing the ultrasonic propagation stability comprises analyzing arrival time distribution, amplitude variation and attenuation rule consistency of ultrasonic response signals in the ultrasonic detection signals.
3. The method of claim 2, wherein the step of determining the position of the substrate comprises, The determination of the discharge propagation dominant characteristic is based on the following logic: if the high-frequency current propagation stability analysis result and the ultrasonic propagation stability analysis result indicate stability, judging that the internal partial discharge is dominant; If the high-frequency current propagation stability analysis result and the ultrasonic propagation stability analysis result indicate instability, judging that the surface discharge is dominant; Otherwise, the composite characteristic is determined.
4. The method of claim 2, wherein the step of determining the position of the substrate comprises, The specific analysis of the high-frequency current propagation stability is as follows: extracting an effective discharge pulse from the high-frequency current detection signal in the period of time; Calculating the amplitude variation coefficient of the effective discharge pulse to represent the amplitude stability; calculating the occurrence time clustering coefficient of the effective discharge pulse to represent time sequence concentration; And judging that the high-frequency current propagation stability is stable or unstable according to the comparison relation between the amplitude variation coefficient and a first amplitude threshold value and the comparison relation between the time clustering coefficient and a first time clustering threshold value.
5. The method of claim 2, wherein the step of determining the position of the substrate comprises, The specific analysis of the ultrasonic propagation stability is as follows: extracting a valid ultrasonic response signal from the ultrasonic detection signal within the time period; Calculating the arrival time discrete coefficient of the effective ultrasonic response signal; Calculating the amplitude variation coefficient of the effective ultrasonic response signal; calculating an attenuation coefficient according to the attenuation curve of the effective ultrasonic response signal, and calculating a variation coefficient of the attenuation coefficient; and judging whether the ultrasonic propagation stability is stable or unstable according to the comparison relation between the arrival time discrete coefficient, the amplitude variation coefficient and the variation coefficient of the attenuation coefficient and the corresponding set threshold value.
6. The method of claim 1, wherein the step of determining the position of the substrate comprises, Determining a dominant discharge mechanism in the detection period, including counting a first period number determined to be internal partial discharge dominant, a second period number determined to be surface discharge dominant, and a third period number determined to be a composite characteristic; and determining the dominant discharge mechanism according to the proportional relation among the first time period number, the second time period number and the third time period number.
7. An uninterruptible power operation insulation tool partial discharge detection system, the system comprising: The acquisition module is used for synchronously acquiring the high-frequency current detection signal and the ultrasonic detection signal on the insulating tool in a detection period; The time period dividing module is used for dividing the detection period into a plurality of continuous time periods, wherein each time period comprises at least one effective discharge event; A stability analysis module for analyzing, for each of the time periods, a high-frequency current propagation stability from the high-frequency current detection signal within the time period, and an ultrasound propagation stability from the ultrasound detection signal within the time period; the dominant judging module is used for judging the discharge propagation dominant characteristic in each time period based on the corresponding high-frequency current propagation stability analysis result and the ultrasonic propagation stability analysis result, wherein the discharge propagation dominant characteristic comprises internal partial discharge dominant, surface discharge dominant or composite characteristic; and the dominant discharge mechanism determining module is used for determining the dominant discharge mechanism in the detection period according to the discharge propagation dominant characteristic determination results corresponding to all the time periods.
8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the method of any one of claims 1 to 6 when executing the computer program.
9. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the method of any one of claims 1 to 6.
10. A computer program product comprising a computer program which, when executed by a processor, implements the method of any one of claims 1 to 6.

Description

Method and system for detecting partial discharge of insulating tool in uninterrupted operation Technical Field The application relates to the technical field of partial discharge detection, in particular to a method and a system for detecting partial discharge of an insulating tool in uninterrupted operation. Background In the uninterrupted operation of the power system, the insulating tool is key equipment for guaranteeing personal safety of operators and stable operation of a power grid, and the insulating performance of the insulating tool is directly related to operation safety and power supply reliability. The tool is exposed to outdoor complex environments for a long time, and poor working conditions are formed on the surface due to humidity change, condensation adhesion or pollutant deposition, so that surface corona discharge or surface micro discharge is initiated. Also, as the service life increases, the insulation tool may age or cause partial discharge inside due to potential defects in the manufacturing process. Under actual operation conditions, the surface discharge and the internal partial discharge are not in mutual exclusion relation, and the surface discharge and the internal partial discharge are always present at the same time and are mutually overlapped, so that the detection signal presents complex mixed state characteristics. Specifically, the high-frequency current pulse generated by the surface discharge has larger amplitude and is easy to mask weak signals of internal partial discharge, the surface water film or the pollution layer can change the ultrasonic propagation boundary condition to cause distortion or attenuation characteristic change of the ultrasonic signals generated by the internal discharge, and the two types of discharge are partially overlapped in time to further cause failure of judgment of 'presence/absence', 'strong/weak' based on the signal amplitude or single event. Most of the existing partial discharge detection methods assume that surface discharge and internal partial discharge can be directly identified in two parts, or only rely on single characteristics of high-frequency current signals and ultrasonic signals to judge, so that the problem of signal aliasing when multiple discharge mechanisms coexist in a complex environment cannot be effectively solved, dominant discharge mechanisms in detection signals are difficult to accurately identify, the reliability of an insulation state assessment result of an insulation tool is insufficient, and potential risks are brought to uninterrupted operation safety. Disclosure of Invention In view of the foregoing drawbacks and deficiencies of the prior art, it is desirable to provide a method and system for detecting partial discharge of an insulation tool during uninterrupted operation. The first aspect provides a method for detecting partial discharge of an insulating tool in uninterrupted operation, which comprises the steps of synchronously collecting a high-frequency current detection signal and an ultrasonic detection signal on the insulating tool in a detection period, dividing the detection period into a plurality of continuous time periods, wherein each time period comprises at least one effective discharge event, analyzing high-frequency current propagation stability according to the high-frequency current detection signal in the time period for each time period, analyzing ultrasonic propagation stability according to the ultrasonic detection signal in the time period, judging discharge propagation dominant characteristics in the time period according to the high-frequency current propagation stability analysis result and the ultrasonic propagation stability analysis result corresponding to each time period, wherein the discharge propagation dominant characteristics comprise internal partial discharge dominant, surface discharge dominant or composite characteristics, and determining a dominant discharge mechanism in the detection period according to the discharge propagation characteristic judgment result corresponding to all time periods. Preferably, analyzing the high-frequency current propagation stability comprises analyzing the amplitude stability and the occurrence time concentration of the discharge pulse in the high-frequency current detection signal, and analyzing the ultrasonic propagation stability comprises analyzing the arrival time distribution, the amplitude change and the attenuation rule consistency of the ultrasonic response signal in the ultrasonic detection signal. Preferably, the discharge propagation dominant characteristic is determined according to logic that internal partial discharge dominant is determined if the high-frequency current propagation stability analysis result and the ultrasonic propagation stability analysis result both indicate stability, surface discharge dominant is determined if the high-frequency current propagation stability analysis result and the ultrasonic pr