Phase- and sequence-domain static models equivalent to long double-circuit transmission lines

The application of equivalent rather than nominal models of transmission lines in various areas of power system studies ensures the accuracy of results when the line length and hence distributed-parameter effect is significant. In this research, the static modeling of long double-circuit lines is comprehensively addressed. Equivalent models are analytically derived for them in different possible operating configurations, incorporating both mutual induction and capacitive coupling between the circuits. This is achieved by finding the solution to the differential equations characterizing the phase voltages and currents of the line circuits. Hence, the equivalent models are first derived in the phase domain, and then the equations are transformed into the sequence domain to obtain equivalent models of sequence networks. The accuracy of the models derived is validated via simulation studies in PSCAD/EMTDC.