Partial discharge fault comprehensive diagnosis method for GIS device

Abstract

The invention discloses a partial discharge fault comprehensive diagnosis method for a GIS device. The method includes the following implementation steps that firstly, three sets of diagnosis results output through an ultrahigh frequency detection method, an ultrasonic detection method and an SF6 componential analysis method of the partial discharge fault comprehensive diagnosis method for the GIS device respectively are respectively output; secondly, a probability matrix is built according to the three sets of diagnosis results; thirdly, a comprehensive diagnosis probability vector is acquired by multiplying the probability matrix by an optimal weight vector; fourthly, the maximum value among the probability value of point discharge, the probability value of suspension discharge and the probability value of particle discharge in the comprehensive diagnosis probability vector is found, the discharge type corresponding to the maximum value serves as a partial discharge fault comprehensive diagnosis result and is output. Early fault hidden danger of the GIS device can be diagnosed, the detection ratio and the accuracy of fault diagnosis are improved, the scientific basis and the guidance are provided for condition overhaul and maintenance of the GIS device on site, and the partial discharge fault comprehensive diagnosis method has the advantages that misjudgment risks are small, and diagnosis accuracy and stability are high.

Description

technical field [0001] The invention relates to the technical field of fault diagnosis of power system substations, in particular to a comprehensive partial discharge fault diagnosis method for GIS equipment. Background technique [0002] In recent years, with the development of urban power grid construction, the number of GIS substations has been increasing. GIS equipment has become the leading switchgear in power systems because of its many advantages. At present, the failure rate of GIS equipment is relatively high. Although the new GIS equipment has passed the product factory inspection and on-site handover test, there are still equipments that have accidents shortly after they are put into operation, and some accidents occur when they are shipped. Moreover, during operation, due to the high internal field strength of GIS equipment, even if a small defect occurs, it is easy to spread, causing equipment failure and causing large economic losses. Therefore, it is necessar...

AI Technical Summary

Problems solved by technology

[0004] 1. Although the ultrasonic detection method is not interfered by the strong electromagnetic environment in the substation, the frequency of the GIS partial discharge ultrasonic signal is low and the attenuation is fast. In the detection frequency band (30-80kHz) of the ultrasonic method, there is strong noise interference outside the substation, especially Natural wind and corona have a great influence on the detection results. Therefore, the ultrasonic method has low sensitivity and poor anti-interference ability, and can only detect very strong partial discharge and mechanical vibration, which is difficult to meet the requirements of GIS partial discharge detection.

[0005] 2. The ultra-high frequency detection method mainly detects electromagnetic wave signals from 0.3 to 3 GHz. It has high sensitivity and strong anti-interference ability, but the problems of quantitative calibration and pattern recognition have not been solved, and it is difficult to accurately judge the state of partial discharge and the magnitude of discharge.

However, the existing research literature has not yet clarified the relationship between the type and severity of partial discharge in GIS equipment, the SF6 pressure and the volume fraction of decomposition products, and because in some failure modes, the content of decomposition gas products does not change significantly, simple There is a large blind area in the diagnosis of gas decomposition products, and the equipment with discharge defects may be diagnosed as normal

Images