Intelligent controllers applied to SVM-DTC based induction motor drives: A comparative study

Direct Torque Control (DTC) has been popular amongst researchers in last few decades. Dynamic and ripple-free control of electric drive has become possible using Space Vector Modulation (SVM) based DTC. Owing the simple structure and wide operating range, PI controllers are used to control torque and flux independently in case of SVM-DTC. But these controllers are less adaptive in situations of change in load, uncertain model or nonlinearities. This demands either for tuning of PI controllers or altogether different control algorithm. This paper presents a comparative study of three algorithms applied to SVM-DTC. 1. Fuzzy Inference System (FIS) tuned PI control algorithm 2. Variable Structure Control based Sliding Mode Control (SMC) algorithm 3. Fuzzy-Sliding Mode Control (FSMC) algorithm. These design strategies are then compared for normal as well as dynamic operating conditions and their capability to handle parameter variations, disturbance rejection is studied. Also a term Integral Time Absolute Error (ITAE) is used as a performance measure to present numerical comparison of the algorithms.