Eight Switch CHB based Three-Phase Shunt Active Filter

This paper proposes an eight switch Cascaded H bridge based three-phase three-wire shunt active power filter for mitigation of multiple power quality problems in source current. The proposed shunt active power filter established by using two H-Bridge and a capacitor in series with coupling inductor for reduction of DC link voltage. So the proposed topology not only save the component count but also reduces the voltage stress across each switch. A drawback of proposed eight switches shunt active filter is, DC link capacitor voltage unbalances. To defeat this drawback, the proposed topology employs a modified feedback control as an additional PI controller. i.e the proposed topology balances the DC link capacitors voltage by controlling both real and reactive power flow. The proposed shunt active power filter is analyses for mitigation of current harmonics, current unbalance and reactive power compensation. The performance of the proposed shunt active filter is analyzed and verified through MATLAB/ Simulink.