Power Quality Improvement Using a Sliding Mode Control of a Series Active Filter

A sliding mode controller (SMC) for a three-phase series active filter was proposed to compensate voltage unbalances, suppress voltage sags and swells and hence improve the power quality of a three-phase ac system. The voltage unbalance compensation and regulation is only based on the positive sequence component decomposition of the supply voltage that is then adjusted to a rated value and used as the reference voltage for the sliding mode controller. This study also includes compensation algorithm, design equations and circuit design criteria. Simulation results ensure the concept and validity of the proposed control system.