Case Analysis of Free Particles Discharge Defects in GIS Equipment Based on Ultrasonic Detection
It is of great significance to find out and eliminate the internal defects in time in the equipment acceptance stage to improve the safe operating margin of power grid equipment.This article introduces a case of discovering free particle discharge in a 220 kV GIS(gas-in-sulated metal-enclosed switchgear)circuit breaker at a certain substation through ultrasonic detection technology.Then,introducing its process of defects detection,comprehensive analysis and equipment disassembly verification.Subsequently,the correct detection methods,interference elimination techniques,defect analysis methods and precise positioning closed-loop results in the process of live detection are described.Innovative methods such as database comparison and waveform characteristic comprehensive analysis were used to accurately de-termine the discharge type,and the discharge position was accurately determined through amplitude positioning method.Finally,through GIS can opening and disassembly processing to discover metal foreign objects inside the GIS circuit breaker chamber,successfully verifying the accuracy of ultrasonic detection technology results and providing experience and reference for the detection and treatment of similar defects in the future.