Study on Transient Response Characteristics of Different Shielded Signal Lines to Lightning Surge Current

This study investigates the transient response characteristics of different shielded signal cables to lightning surge currents. Based on the on-site layout of surge tests, it examines the variations in open-circuit voltage or short-circuit current at the core terminals of various cable systems under two combinations of surge waveforms (1.2/50&8/20 μs and 10/700&5/320 μs). It also measures the load voltage and current responses when resistive loads are connected at both ends, while analyzing the corresponding frequency spectra and energy spectra. The results show that the response characteristics of two types of electrical cables, such as single-shielded signal cables, mainly depend on the physical properties of the core conductors; the spectral responses are concentrated within 20 kHz, with the 1.2/50&8/20 μs waveform corresponding to the mid-frequency band and the 10/700&5/320 μs waveform corresponding to the low-frequency band; the increase in the energy spectrum is concentrated within approximately 50 μs; the core conductor structure plays a decisive role in influencing the response characteristics, and the ratio of short-circuit current to open-circuit voltage is positively correlated with cable length.