Analysis of asymmetrical faults in power systems using dynamic phasors

This paper presents application of the dynamic phasor modeling technique to unbalanced polyphase power systems, The proposed technique is a polyphase generalization of the dynamic phasor approach, and it is applicable to nonl inear power system models, In a steady-state, the dynamic phasors reduce to standard phasors from AC circuit theory. The technique produces results th at are very close to those obtained from time-domain simulations. Simulatio ns in terms of dynamic phasors typically allow larger integration steps tha n the standard time-domain formulation. We present simulations of unbalance d faults involving a three-phase synchronous generator connected to an infi nite bus through a transmission line, and we demonstrate that models based on dynamic phasors provide very accurate descriptions of observed transient s.