Predictive Fuzzy Based Sliding Mode Control of an Induction Motor

This paper presents a predictive fuzzy based sliding mode controller for a vector controlled induction machine (IM) fed by a three phase voltage source inverter (PWM). The proposed predictive fuzzy sliding mode control method combines features of both indirect vector control (sliding mode control) and DTC (model predictive control). The sliding mode control is a nonlinear, high speed switching, feedback control strategy for controlling the nonlinear system (IM).The model predictive control is used to precalculate the behavior of the system and choose an optimal switching input for voltage source inverter. The sliding mode parameters can be adjusted to get faster error convergence, however, this will, in turn, increase the control gain, which may produce severe chattering on the sliding surface and, therefore, deteriorate the system performance. To cope with dynamic uncertainty and external load, a fuzzy sliding mode control (FSMC) is designed by incorporating a fuzzy inference mechanism into the existing sliding mode control scheme to reduce the chattering problem. A predictive fuzzy sliding mode controller (PFSMC) has been designed and the functions are verified through MATLAB-Simulink.