Design of an On-Line Monitoring System for Partial Discharge of Gas Insulated Switchgears

An ultrasonic on-line monitoring system for partial discharge of gas insulated switchgears (GISs) was designed based on optical fiber transmission and LabVIEW virtual instrument. The system comprised an ultrasonic wave sensor, remote high-speed acquisition modules, a local modulus and the upper computer software. By utilizing the optical fiber transmission technology, partial discharge signals of GISs were reliably acquired at a high speed. By accurately extracting partial discharge signals, the upper computer software system was developed through LabVIEW graphical programming language. Based on this, this research built the test platform for partial discharge of GISs and simulated four typical types of faults commonly seen in the operation of GISs. By combining with the system and using ultrasonic method, the whole discharge process of different discharge models was detected, thus obtaining the feature database of ultrasonic signals during partial discharge under each defect model. The test research and field application verify the effectiveness of the system and the algorithm proposed in this study.