A comparison between random hysteresis current control technique with bipolar and unipolar modulations

Abstract

Current control methods play an important role in power electronic circuits. Among them, a hysteresis current control method has been used largely on AC motor drives due to a good dynamic response and simple operation. The Random Pulse Width Modulation (RPWM) technique distributes the spectrum contents of load current without affecting the fundamental component, and it may reduce the acoustic noise and mechanical vibration of an inverter-fed induction motor drive when the amplitude of harmonics around side bands is decreased. This paper presents a Random Band Hysteresis Current Control (RBHCC) technique with bipolar and unipolar modulations, and compares spectrum contents of a load current. Mathematical analysis and simulation results show that the RBHCC with unipolar modulation has no considerable effect on distributing the spectrum contents of the load current compared to the bipolar modulation technique.