Study on interface algorithm for power system transient stability hybrid-model simulation with UPFC device

A new hybrid simulation algorithm of alternative iteration is introduced to handle the interface between the UPFC and the power network. Dynamic phasors method in modeling UPFC is discussed, and then UPFC control system is also analyzed. Terminal voltage control and firing angle control of converter are adopted to keep constant the UPFC terminal bus voltage magnitude and the UPFC DC capacitor voltage respectively in shunt side control, and also terminal voltage control and firing angle control of converter are used to keep constant the real power and reactive power of the line in series side control. First results show the approximate precision between dynamic phasors model and electromagnetic transient; second results on 2-area system show the proposed UPFC dynamic model and the UPFC-network interface work very well in system transient stability analysis. Moreover, the proposed hybrid simulation scheme would be efficient in transient stability analysis withasymmetrical faults in interconnect power system including FACTS devices.