To investigate the influences of disconnector in gas insulated switchgear（GIS） switching-on/off on electromagnetic compatibility of electronic transformer

we investigated the influence level and coupling paths of multiple electromagnetic disturbances on electronic transformer

and developed an electromagnetic compatibility testing system of electronic transformer based on 500 kV GIS disconnector switching.The testing system can measure transient process induced by 500 kV GIS disconnector switching-on/off and output waveform of electronic transformer simultaneously.Typical waveforms of VFTO and VFTC

breakdown voltage characteristics

the arcing law of the disconnector

and typical faults of electronic transformer can be obtained in this testing system.The VFTC has its highest amplitude of 826.8 A

with a rising rate about 6.51 kA/μs.The VFTO has its maximun overvoltage multiple of 1.22

with a rising rate about 17.2 kV/μs.Testing results prove that the transient measurement results accord with theoretical expectation

and reflect the real situation of transient process exactly.There are significant differences between IEC standard of electronic transformer and electromagnetic environment in substations.Anti-interference ability of the transformers can be improved effectively by proposing anti-interference measures according to different coupling approaches.