Self-tuned NFC and adaptive torque hysteresis based DTC scheme for IM Drive

This paper presents a simplified self-tuned Sugeno type neuro fuzzy controller (NFC) based direct torque control (DTC) scheme for induction motor (IM) drive. A simple tuning algorithm is developed based on the reference and actual acceleration of the motor. The online tuning strategy adjusts the parameters of the consequent layer of the NFC in such a way to minimize the square of the error between actual and reference acceleration of the IM. In a conventional DTC scheme the band limits of flux and torque hysteresis controllers remain fixed and hence the torque and flux ripples are high. In order to optimize the torque ripples of the IM the hysteresis band limits are adjusted online for the torque hysteresis controller. In order to test the performance of the proposed NFC based DTC scheme for IM drive a complete simulation model is developed using MATLAB/Simulink. The proposed NFC based DTC scheme is implemented in real-time using DSP board DS1104 for a prototype 1hp squirrel cage IM. The performance of the proposed drive is tested at different operating conditions in both simulation and experiment.