Performance Improvement and Simplification of Hysteresis-Band Current Controller for Shunt Active Power Filter

A hysteresis band instantaneous current control PWM technique is popularly used because of its simplicity of implementation, fast current control response, and inherent peak current limiting capability. However a current controller with fixed hysteresis band has the disadvantage that the switching frequency varies widely over a cycle and as a result generates non optimum current ripple at the output. This also may led to injection of low-order harmonics into grid which couldn’t be filtered easily. This paper describes a novel method to overcome these problems. The proposed method could be easily implemented and is completely reliable. Finally, in order to verify the validity of proposed method the simulation is done with MATLAB/Simulink toolbox.

Keywords:

Active Power Filters , Harmonic spectrum , Hysteresis Band , Simplified and modified hysteresis band