An Investigation of Electromagnetic Transients for a Mixed Transmission System With Overhead Lines and Buried Cables

An electromagnetic transient study has been performed based on a practical 500 kV mixed transmission system. The system overhead lines, submarine cables and underground cables. exact expression of earth-return impedance for cable developed. A new equivalent homogeneous earth method (EHEM) is also proposed the formula. influences air, seawater, seabed, wired armor structure multi-layer seabed series modal propagation constants are investigated. novel modeling procedure parametrical side in this paper. Moreover, input sequence impedances studied traditional Line / Cable Constant routines method. Transient simulations using classical methods. results further validated with recently MoM-SO technique.