Double Band Adaptive Hysteresis Current Control Employed in Active Power Filter

摘要

Shunt Active Power Filters (APF) are widely used in power systems to eliminate the current harmonics and to compensate reactive power due to their accurate and fast operation. Hysteresis Current Control (HCC) is one of simplest and fastest modulation techniques which is implemented very easily. The practical concern with implementing the Fixed Band Hysteresis Current Control (FBHCC) in APFs is its variable switching pattern which, in turn, results in increasing the risk of occurrence of resonance in power systems and raises the switching losses. To avoid this situation, adaptive HCC (AHCC) methods with the variable hysteresis bands have been recommended in literature. In this paper, a new method in using second band for AHCC has been proposed. The second layer is calculated adaptively as well as the first one. The simulations have been done to demonstrate the efficiency of this method in fixing the switching frequency and reducing THD of source current.