Triple-frequency inductive voltage withstand test of electromagnetic voltage transformer for 110 kV GIS
Chuan Cai · Dianli zidonghua shebei · 2011
The AC voltage withstand test is applied to detect the insulation defects of EVT(Electromagnetic Voltage Transformer) in GIS.Two kinds of on-site triple-frequency test methods are presented with test wiring diagrams and test procedures.The voltage input and the compensating reactor are connected to different windings of EVT in the first method while to the same winding in the second method.The cause of capacitive voltage-augment and its influence,the necessity of no-load test and the determination of voltage withstand test duration are analyzed by calculation and compared between two methods.The results of field triple-frequency inductive voltage withstand test indicate the relationship among primary current,secondary current and compensating reactance,showing the first method is more suitable for EVT in GIS.