FLC Based DTC Scheme to Improve the Dynamic Performance of an IM Drive

This paper presents a fuzzy logic controller (FLC) based direct torque control (DTC) scheme for speed control of IM drive over a wide speed range. The FLC is used to adjust the bandwidth of torque hysteresis controller in order to reduce the torque ripple of developed torque and hence to improve motor dynamic response. The effects of torque hysteresis band amplitude on the torque ripple of IM are also discussed in the paper. The FLC is designed to select the optimum amplitudes of the three level torque hysteresis controller based on the variation in motor speed. In order to test the performance of the proposed FLC based DTC scheme for IM drive a complete simulation model is developed using MATLAB/Simulink. The proposed FLC based DTC scheme is implemented in real-time using DSP board DS1104 for a prototype 1/3 hp motor. The performance of the proposed drive is tested at different operating conditions both in simulation and experiment.