A single-phase transformerless active filter with reduced DC-link voltage

This paper proposes a Hybrid series active filter (HSeAF) without interfacing transformer. The compensator improves power quality issues of a single phase system. A control algorithm to compensated current harmonics of a nonlinear load to propagate into the single-phase system, while protecting loads from voltage perturbations initiated from the power system is studied. The exclusion of the series transformer reduces complexity and overall costs of this configuration. The compensation of current harmonics and load voltage distortions are analyzed together with the influence of gain and delays in the controller stability. The detailed operation of the proposed topology is presented and analyzed in a comparative study with conventional series active filters. Validation by simulations of the system dynamic for different load and supply conditions is presented.