Series power quality compensator for voltage sags, swells, harmonics and unbalance

This paper deals with a static analysis and implementation of the control scheme for a three-phase series power quality compensator (SPQC) to mitigate voltage sags and swells, reduce voltage harmonics and eliminate voltage unbalance. The SPQC consists of three single-phase IGBT based voltage source inverters (VSI) used as a series active filter and a three-phase PWM shunt rectifier with a dc link capacitor. The kVA rating of main circuits is analyzed. An improved direct voltage comparison method is applied in the control strategy of series active filter. The control algorithm of the shunt rectifier uses a PI controller with two closed loops. The hardware structure of the digital signal processing (DSP) control system is also proposed. The simulation and experiment results are presented to illustrate the effectiveness of the SPQC in improving power quality in distribution system