Auto-tuning sliding mode control for induction motor drives
This paper presents an adaptive fuzzy sliding-mode controller (AFSMC) based on the boundary layer approach for speed control of an indirect field-oriented control (IFOC) of an induction motor (IM) drive. In general, the boundary layer approach leads to a tradeoff between control performances and chattering elimination. To improve the control performances, a fuzzy system is assigned as reaching control part of the fuzzy sliding-mode so that it eliminates the chattering completely in spite of the large uncertainties in the system. The applied fuzzy controller acts like a saturation function with a nonlinear slope inside thin boundary layer near the sliding surface to guarantee the stability of the system. Moreover, an adaptive law is implemented to estimate the unknown bound of uncertainty, which is obtained in the sense of Lyapunov stability theorem to minimize the control effort. The proposed AFSMC-based IM drive is implemented in real-time using DSP board TI TMS320F28335. The experimental and simulation results show the effectiveness of the proposed AFSMC-based IM drive at different operating conditions.