Developments in techniques for simulating faults in e.h.v. transmission systems

In the study of the faulted response of power systems, synchronous sources are often represented by subtransient impedances. Alternatively, more elegant synchronous-source models are often combined with simplified models of transmission-line interconnections. In the paper, methods are developed which enable more accurate models of synchronous sources to be combined with generator/transformer and distributed-parameter frequency-variant transmission-line interconnections. The methods are developed by reference to a single generator connected to an assumed-infinite busbar via a delta-star transformer and a transmission line, the techniques relating to digitally simulating the synchronous source having been established in an earlier paper. The paper concludes with a presentation of some computational results relating to faults at the remote end of a 400 kV interconnection of length 160 km.