Sliding Mode Variable Structure Control for Three-Phase Three-Wire Active Power Filter

Abstract

Based on the established three-phase three-wire active power filter model, a sliding mode variable structure control method is designed. Since the active power filter (APF) is switched by the switching function continuously, a suitable sliding surface is an effective method for improving the current tracking performance. Although the ordinary hysteresis comparison method has the characteristics of fast dynamic response, good robustness and strong adaptability to loads, the chattering phenomenon is serious. In this paper, a new sliding mode variable structure control is constructed by the design of sliding surface. The simulation proved that the designed sliding mode variable structure control method has less chattering and current tracking error than hysteresis comparison, the current contains fewer harmonics after processing. The effect of overall harmonic compensation is better than the ordinary hysteresis comparison method.