Center-point-clamped AC-AC buck-boost harmonic compensator based power quality device

A novel approach for mitigation of power quality issues have been presented in the paper. This paper introduces a Center-Point-Clamped AC-AC Buck-Boost Converter based power quality device for industrial and residential customers at the leaf end of the distribution network. This converter utilizes the principle of center-point-clamping to reduce the voltage stress on the power semiconductor switches. It can buck, boost and eliminate unwanted line frequency harmonics from the input voltage by controlling the duty ratio of the switches, thereby providing desired voltage at the customer side with minimal THD. A closed loop strategy has also been presented in the paper. This feedback regulator improves the steady state and transient performance of the converter. Simulation results displayed in the paper verify the feasibility and effectiveness of the proposed power quality device in mitigation of power quality issues like voltage sag, voltage swell and harmonics at multiple order of line frequency, have been displayed in the paper. A small scale experimental prototype rated at 120V, 1-kW has been constructed in the laboratory. Experimental results further corroborate the theoretical and simulated analysis, and demonstrate the merits of the proposed approach.