Application of frequency domain analysis to fault transients in complex HV transmission lines

Transients upon faults can be analyzed by the time domain approach adopted e.g. in available EMTP based software. When the connection becomes complex and the effect of circuit parameters must be systematically evaluated, the efficiency drops and simplifications are required to limit computation time. For a new connection (Randstad380) the complexity is related to the embedded mutually coupling cables (2 circuits, 2 cables per phase) and the use of cable joints over varying distances. This paper applies an alternative approach that analyzes transients upon faults in frequency domain. The modeling procedure is presented in detail and it is applied to the Randstad380 south-ring connection. Comparison is made with PSCAD/EMTDC modeling based on a simplified transmission line configuration, which is suitable for time-domain simulation. The results show that the presented method is able to effectively and accurately analyze fault transients.