Observation and analysis of lightning induced overvoltage on buried cables

The experiments have been conducted about lightning electromagnetic pulse (LEMP) coupling to buried cables in the depth of 0.5 m. The test system and the measurement method are both introduced, and the lightning induced overvoltages at the end of the buried cables are analyzed. The cables are used in automatic weather stations, i.e. the power cable without shielding layer, the signal cable with a braided copper shield and the control cable with a steel shield. Relative to the peak voltage induced on the power cable, the peak voltages induced on the control cable and the signal cable are 65% and 26% respectively. The peak induced overvoltage of the three cables has a similar trend in the initial stage of the LEMP. The steel belt shielding layer can effectively reduce 400 kHz～1 MHz componen