MFACTS System Studies

The unified power flow controller (UPFC) combines the advantageous features of both shunt and series compensations; therefore, it is an effective device that can adjust power system parameters in order to increase power transfer capability, stabilize the system and improve the economics of a power system. This paper presents the exact pi-model of the UPFC-inserted transmission lines from which the injection-model using two-port networks is derived. The equations derived in this paper are applied to a small test system, where the impact of UPFC on OPF results is shown.