Affection of shielding methods on the characteristics for cable coupled to lightning impulse magnetic field

The lightning-induced current in the cable can be reduced by using appropriate shielding methods. A circular double ring lightning impulse magnetic field is created by injecting 8/20 mu s standard lightning surge current into the coil, which is coupled to 9 types of measured cables, including cable without shielding layer (SL), single SL and double SL cables. The effect of shielding on the lightning surge current is evaluated for various shielding strategies. This study's findings demonstrate that grounding both SL sides efficiently lowers the induced current in cables, which is 80% less than the induced current when the SL is not grounded. Grounding both sides of the outer SL and one side of the inner SL is the optimum shielding approach for double SL cable. Furthermore, grounding one side of the SL suppresses electrostatic induction between the circular double ring lightning impulse magnetic field and the cable but has no significant shielding effect. Ultimately, some engineering recommendations, presented through a comparison of different shielding methods with related work, are proposed in this paper.(c) 2022 Elsevier Ltd. All rights reserved.