A simple sliding mode control of an active power filter

In this paper a simple sliding mode control for a single-phase active power filter, using the quasi-steady-state approach is proposed. The proposed control avoids the use of an analog multiplier and the sensing of the source voltage, both required for previous control methods. The sliding mode control designed allows us to compensate the harmonic distortion and phase displacement of the line current using only operational amplifiers, analog switches and a flip-flop. The proposed control is suitable for analog implemented low cost active filters. The main goals of the proposed control are a low total harmonic distortion, high robustness under external disturbances, and a good dynamic response.