Buck-Boost converter based SHE-PWM technique multilevel inverter control for STATCOM system

This paper presents a Selective Harmonic Elimination-PWM technology(SHE-PWM) for STATCOM (Static Synchronous Compensator) system employing H-Bridge multilevel inverter configuration. In this method variable DC voltage is used and the lower order harmonics are eliminated, without affecting the structure of the inverter. This method gives constant switching angle, so it reduces the number of steps required for offline calculation. The proposed method optimizes the DC-DC converter topology for high efficiency with high voltage capacity. In this paper a Buck-Boost converter is used. Current and voltage closed loop controllers are used to meet reactive power demand under varying load condition.