A Study of Fast Front Transients of an HVDC Mixed Transmission Line Exposed to Bipolar Lightning Strokes

Bipolar lightning strokes are associated with multiple polarity electrical discharge no current intervals in between, making their behavior quite peculiar. This work presents a fast front analysis of mixed high voltage direct (HVDC) transmission link, evaluating the factors that influence line transients due to shielding failures and backflashovers (BFOs), considering both overvoltage repeated reversal at cable sending terminal. The research process includes detailed modeling bipolar stroke, frequency-dependent HVDC overhead, underground sections. Noticeable findings include occurrence only positive insulator BFO for adjacent subsequent tower, despite dual stroke relatively small values parameters. traveling waves on flashover performance varying parameters (such as riser section length, tower grounding impedance, location stroke) is recorded explained.