The study of Transformerless Shunt Hybrid Active Power Filter compensation for unbalanced load

This paper studies on the compensation characteristics of Transformerless Shunt Hybrid Active Power Filter (TLS-HAPF) under unbalanced load conditions. TLS-HAPF is formed by a single-tuned passive LC filters in series with active filter without transformer. This topology has the advantage of low capacitor voltage and can compensate for high capacity nonlinear loads. With the widespread application of unbalanced loads, this paper proposes a control strategy for APF that extracts fundamental negative sequence current, which makes this topology achieve the compensation for unbalanced load. Simulation results performed in MATLAB verified the validity of the new approach.