LCL filter based UPQC configuration for power quality improvement

This paper proposes a unified power quality conditioner (UPQC) configuration employing an LCL filter at front of shunt voltage source inverter (VSI). As compared to conventional UPQC with L filter at the front of the shunt VSI, the proposed UPQC provides improved compensation while using much smaller value of filter inductance. With the smaller filter inductance, voltage requirement of common dc link also gets reduced. It results in reduced switching losses in the series and shunt VSIs. Therefore, proposed UPQC achieves reduction in weight, cost, size, and losses while providing improved current compensation capability. Simulation results are presented to verify all the features.