Site-Specific Transient Effects of Return Strokes on Buried Cables From Rocket-Triggered Lightning Strikes

Using the rocket-and-wire technique, this study investigates the dynamic behavior of buried cables during lightning strikes at various locations, and specially focuses on the voltage waveforms observed during return strokes. The analysis examines waveform signatures and parameter variations at five distinct strike points: launch tower 1, launch tower 2, the wind turbine, the remote earth, and the substation. Double-peak signatures are observed in the voltage waveforms during return strokes at the launch towers and remote earth. Positive polarity is dominant at the lightning towers and remote earth, while negative polarity prevails at the wind turbine and substation. The study also observes significant variations in six voltage parameters across the different strike locations, with voltage peaks ranging from 80 V to 1010 V. The highest average voltage peak (672.6 V) presents when lightning strikes the wind turbine, followed by 416.7 V at the substation and 16.4 V at the remote earth. Additionally, the voltage waveform at the remote earth exhibits a higher inverse-peak ratio and longer rise time compared to other locations. These findings offer valuable insights into the complex interaction between lightning discharges and buried cables, and highlight important factors for developing effective lightning protection strategies for buried cables.