A full-bridge AC power flow controller with reduced capacitance operated with both FFS (Fundamental frequency switching) and PWM

This paper proposes a single-phase full-bridge series reactive power compensator with a reduced size of the capacitor. Series compensator can be used for power flow controller and voltage stabilizer in power transmission and distribution system, and usually injects only several percent of the system voltage; therefore, FFS (Fundamental frequency switching) can be a candidate for high power applications. This paper introduces operation principles and control methods for both of the FFS and PWM operation with the reduced capacitance. Harmonics analysis of the FFS operation is shown. Optimum capacitance from the point of dimension is discussed, and a considerable size reduction of the capacitor compared with usual low voltage ripple design is suggested to be achieved.