Design of a fuzzy sliding-mode controller for induction motor vector control systems

This study purposed a sliding-mode controller (SMC) with a variable sliding surface (slide plane). This SMC was then applied to a direct field-oriented control (FOC) system without speed sensors developed for an induction motor. To improve the performance and robustness of the drive, fuzzy theory was integrated with sliding-mode control. For this integration, fuzzy sliding surfaces were used as a substitute for sliding surfaces with fixed slope constants to reduce the time required for system trajectories in the reaching mode to reach the sliding surface, and to reduce high-frequency chatter. A fuzzy sliding-mode controller (FSMC) was incorporated into the framework of an induction motor vector control system. The experiment and simulation results showed that the system provided excellent dynamic performance and could effectively reduce parameter variations or perturbations with a torque of 8 Nm and rotational speeds of 36, 1200, and ±1500 rpm.