Lightning-Induced Magnetic Field Distribution on Cable-Stayed Bridge Based on Modified Equivalent Circuit Method

In order to protect sensitive devices on the cable-stayed bridge against the effects of lightning electromagnetic pulse, detailed information about the lightning currents and the radiated electromagnetic fields are necessary. For this purpose, a modified equivalent electric circuit method is presented for evaluating the electromagnetic environment on a cable-stayed bridge during direct lightning strikes. The stayed cables of the bridge are modeled as cascade polylines to transform the internal metallic structure of the bridge into an equivalent electrical circuit network. Taking a bridge for example, the current distribution and the lightning-induced magnetic field distribution are calculated based on the proposed method. The guidelines for the protection of sensitive electrical and electronic equipment against lightning are provided.