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With the continuous development and construction of the power grid system, 220kV GIS equipment has been widely used in ultra-high voltage substations. Before leaving the factory, GIS equipment needs to be tested for lightning impact, partial discharge, etc. to check whether there are problems in the manufacturing, assembly and other links of the equipment. This paper analyzes a 220kV GIS when the partial discharge test (factory test) occurs when the partial discharge exceeds the standard. By using the directional elimination method, the equipment fault range is determined, and the fault structure is disassembled. Analysis, X-ray flaw detection results found that the insulation There are tiny bubbles in the base, indicating that the assembly workshop has problems of technical control or lack of cleanliness. At the same time, after the insulation base has been subjected to multiple lightning strikes, due to the cumulative effect, the equipment has exceeded the standard in the partial discharge test. Finally, through the analysis of the cause of the failure, the targeted rectification measures are put forward to improve the technical management and control level of the assembly workshop.

In response to a recent 500kV line shunt reactor high-voltage bushing failure event in a station, This article examines and analyzes the objects and protection actions after the casing is disassembled. It was found that the cause of the casing failure was caused by the arc igniting the insulating oil in the casing after the main insulation of the casing was discharged. Finally, corresponding preventive measures are proposed from the perspective of on-site operation and maintenance.

Aimed at solving the problem of the end shield fault of 500 kV capacitive bushing which happened frequently in the main power grid in recent time, two faults are taken as examples to analyze the fault characteristics and reasons of the spring cap type end shield devices. On that basis, effective revention measures and modification schemes for the spring cap type end shield devices of 500 kV capacitive bushing are proposed from perspectives of the equipment security operation and maintenance, and personal safety.

In recent years, with the development and construction of the power grid system, the porcelain column circuit breaker has been popularized and applied in the 500kV substation. However, in the actual operation and maintenance process, the leakage of oil has been found in the grading capacitor. The disassemble of an oil leakage grading capacitor of a 500kV porcelain column circuit breaker is analyzed in this paper. Through carrying out the sealing test; the insulation performance test; salt spray test and simulation test. At the same time, by comparing the sealing ring and cover plate material; calculating the potential difference of the cover plate and researching electrochemical corrosion factors. We can come to an conclusion that the cause of a suspected the grading capacitor oil leakage is the oil accumulation; and the main reason for the oil leakage problem of the grading capacitor is the electrochemical corrosion phenomenon on the sealing cover plate. Finally, on the basis of the reasons, the relevant rectification measures are put forward.

This paper analyzes the cause of a 500kV gapless MOA fault in a substation. The appearance inspection and disassembly analysis of the arrester are carried out. Combined with the protection action, the fault cause of the arrester is analyzed. It is found that the fault is caused by the side flashover failure of the local resistor piece of the line arrester due to the steepness of the lightning invasion wave is large. When the line is reclosed, the lower section bears the over-voltage, resulting in the damage of some resistors, and then causes the pressure release. Based on the analysis the paper puts forward some corresponding operation and maintenance measures.