Abstract
To lower the lightning impulse withstand voltage of electric power equipment while maintaining the high reliability of its insulation performance, it is important to define in an organized way the insulation characteristics for non-standard lightning impulse waveforms that represent actual surge waveforms in the field and compare them with the characteristics for the standard lightning impulse waveform quantitatively. This paper introduces the method using overvoltage duration for converting non-standard lightning impulse waveforms into standard lighting impulse waveforms equivalent in terms of insulation intensity.
