Study On Partial Discharge Testing And Positioning Technology For GIS

Shanghai power grid is put into operation in the early 1980 s the first generation of GIS equipment.As the growth of the equipment in service time and new GIS equipment are put into operation,the number of GIS equipment faults have been gradually rising trend.Insulation performance of GIS in the operation of the equipment tracking detection is an important means of GIS in risk assessment.This paper firstly analyzes the main insulation defects that cause GIS partial discharge type.Secondly the theory of the ultra-high-frequency(UHF)method and the ultrasonic method applied to on-line partial discharge(PD)testing for GIS under normal operation was presented,and based on that an electrical and ultrasonic combined method for testing was proposed.Field application showed that the combined method can be used to simultaneously test the UHF signal and ultrasonic signal from the PD signal,which can more effectively exclude field disturbance to detect the insulation faults of GIS.During the test,the UHF method was first used for primary PD positioning,and then the combined method was applied for accurate positioning.Finally,application of the method by State Grid Shanghai Maintenance Company was presented,which can provide reliable data for GIS maintenance.