Control of a Novel UPFC Based on Nine Switch AC/AC Converter

Unified Power Flow Controller (UPFC) is one of the most comprehensive FACTS devices which can controls three system parameters independently. In this paper a novel configuration of UPFC which consists of a nineswitch ac/ac converter parallel with a series capacitor has been proposed to inject desired series voltage. It means that operation of nine-switch ac/ac converter in this configuration is the same as combination of two dc/ac converter in conventional UPFC. However, proposed configuration needs fewer power electronics switches and gate drive circuits and control scheme becomes simpler than conventional UPFC configuration. using series capacitor parallel with nine–switch ac/ac converter reduce the injection voltage’s THD, eliminate output filter, and reduce the converters power rating in comparison with conventional UPFC composed of series and shunt converters. The proposed UPFC is modelled using MATLAB/SIMULINK software and simulation results are presented to indicate good operation of the novel UPFC.