Research on the hybrid topology of unified power quality conditioner based on direct control philosophy

This paper presents the direct control philosophy to compensate the power quality problems utilizing unified power quality conditioner (UPQC). The series part of UPQC is controlled as a sinusoidal current source by using a three-phase full-bridge voltage-source inverter, while the shunt part is controlled as a sinusoidal voltage source by using a four-leg voltage-source inverter. The mathematic model of UPQC is set up. The performance of proposed UPQC system was analyzed under non-ideal and unbalanced load conditions. The simulation results based on Matlab/Simulink are presented to show the effectiveness and feasibility of the topology structure and control philosophy.