Variable hysteresis current controller with fuzzy logic controller based induction motor drives

One of the most popular and easy to implement control strategy for the inverter in induction motor drive system is the hysteresis current control. The most drawbacks associated with the conventional hysteresis current controller is the variable switching frequency due to the constant hysteresis band. This paper aims to develop variable hysteresis band with fuzzy logic controller which can produce constant switching frequency. Matlab/Simulink environment was utilized to conduct the simulation of induction motor drives with three different configuration of hysteresis control; fixed hysteresis band, variable hysteresis band and fuzzy hysteresis band. The obtained results shows that, fuzzy hysteresis band produce better results than the fixed and variable band in which constant switching frequency, less ripple and reduced harmonics contents in the current waveforms. Hence fuzzy based hysteresis current controller proved to be superior in terms of switching frequency and harmonics contents.