Impulse Discharge Voltage Prediction of Air Gaps

Abstract

The lightning overvoltage and switching overvoltage in power systems are both impulse voltages with short duration time and large change rate, under which the air gap breakdown characteristics are different from those under steady voltages. This chapter firstly introduces the air gap breakdown characteristics under lightning and switching impulse voltages. Then, the air insulation prediction model is used to predict the switching impulse discharge voltages, lightning impulse discharge voltages and volt-time characteristic curves of air gaps with different geometries and under different voltage waveforms.