Identification of Lightning Disturbance in Ultra-High-Speed Transmission Line Protection

The application of ultra-high-speed protection based on traveling-waves or transient components suffers mal-operation in case of lightning strokes on transmission lines. This paper analyzes the spectra and traveling-wave waveforms of current transient components to find the differences in energy distribution and waveform. The characteristics are as follows: the signal energy of short-circuit faults and lightning-induced severe faults mainly focuses at low-frequency band; the signal generated by non-faulty lightning (lightning disturbance) and lightning-induced weak faults contains lots of high-frequency components; relative to lightning disturbance, the chopped wave caused by lightning-induced weak faults is obvious. According to the differences, the paper proposes a method to identify lightning disturbance based on the features of energy distribution and chopped wave. EMTP simulation tests prove the method is feasible