Optimizing Shielded Cable Lightning Protection: Effects of Grounding and Shielding Under Variable Lightning Surge Conditions

Lightning-induced coupling effects pose substantial risks to the safety of power and signal transmission systems, particularly in complex electromagnetic environments. This study comparatively evaluates the shielding effectiveness (SE) of various shielded cables under two typical lightning surge waveforms. To simulate the coupling effects of lightning electromagnetic pulses, an experimental platform based on dual circular coils is established. The induced responses of various cable configurations are recorded and analyzed in time, frequency, and energy domains. The evaluated shielding strategies include single-ended grounding, double-ended grounding, and metal pipes with different coverage ratios. Results show that double-ended grounding markedly improves shielding performance under both waveforms, while multilayer shielding outperforms single-layer designs in suppressing both high-frequency and low-frequency interference. Note that, metal pipe shielding is only effective when fully covering the cable and grounded at both ends, yet underperforms compared to intrinsic cable shielding. Sensitivity analyzes further reveal the critical influence of geometric parameters on the induced response, with lower cable height drastically reducing magnetic loop coupling. Short pulses induce high transient currents and exert significant stress on magnetic coupling paths, while long pulses primarily trigger capacitive coupling. In addition, the energy accumulation analysis highlights the distinct temporal energy injection profiles of different surge waveforms, which informs protection strategies against both immediate impulses and prolonged stresses. These research findings offer practical guidance reference for the optimal selection and installation of shielded cables in lightning-prone environments.