Time-Domain Hybrid Method for the Coupling Analysis of Power Line Network With Curved and Multidirectional Segments

Currently, numerical methods used for the coupling analysis of power line network, integrating the structural features of curve and multiorientations, are still rare. An efficient time-domain hybrid method consisting of the finite-difference time-domain (FDTD) method, transmission line (TL) equations of Agrawal model, coordinate transform, and S-parameter cascade techniques is presented in this work, which can realize the fast-coupling simulation of power line network with curved and multidirectional segments (PLN-CMS). First, the overall structure of PLN-CMS is decomposed into a cascade network of multiple independent curved power line segments and connecting nodes, and the ports of each power line segments are equivalent modeled by matched loads. Then, the coupling model of each curved power line segments with arbitrary orientation is constructed via the TL equations of Agrawal model combining with the coordinate transform technique, and the transient responses on these curved power line segments and matched loads are solved by the FDTD method. Finally, S-parameter cascade technique is applied to deal with the scattering voltages at the connecting nodes to realize the data transmission of interference signals between these curved power line segments. Numerical simulations for the coupling analysis of PLN-CMS constructed by single line or double lines on the ground excited by strong electromagnetic pulse are considered to verify the correctness and efficiency of the proposed method by comparing with the method of moments in terms of precision and time consumption. On this basis, the coupling characteristics of lightning electromagnetic pulse acting on the actual three-phase power line network are simulated and analyzed.