Three‐phase overvoltage at lightning strike point due to direct triggered lightning to the phase wire of 10 kV power distribution line

Abstract

This paper reports the observation results of three-phase overvoltage at the lightning strike point of a 1.5 km, 10 kV power distribution line that was struck directly by rocket triggered lightning to its phase wire C. The arrester of the direct struck phase at the lightning strike point operated in all return strokes corresponding to return stroke current from −3.3 kA to −32.9 kA. The waveform of direct struck phase includes an initial spike before negative peak, operation area of metal oxide varistor, and the final attenuation with oscillation. The overvoltage waveforms of the indirect struck phase at the lightning strike point show a small initial negative peak, rapid transition to a large positive peak, and the final negative attenuation with oscillation. The negative peak value of the indirect struck phase at lightning strike point ranged from −4.1 kV to −25.2 kV and that of the direct struck phase was between −78.1 kV and −167.8 kV. The positive peak value of indirect struck phase was between 0.2 kV and 49.8 kV. The negative peak value, zero-crossing time and the peak-to-peak value of voltage all have a good linear relation with the peak value of lightning return stroke current.