Generating the Switching Impulse with Long Time Front by Concatenated Test Transformer

This paper introduces the theory and method of generating the switching impulse with long time front by using capacitor bank discharge to primary winding of the testing transformer. Studies of effects on switching impulse waveform and utilization coefficient by main capacitance, harmonic inductance, harmonic resistance and charging voltage of the capacitance are emphasized. Voltage distribution of transformers in all levers are also calculated in theory and measured when switching impulse is generated by the testing transformer. Finally the first suit of test set in our country has come into being which generate the switching impulse with long time front, and it is consist of concatenated test transformer, capacitor bank and auxiliary device. The test set also is applied to the study of external insulation of UHV transmission line of megavolt lever.