The self-adjustable fuzzy sliding mode control for AC speed drive systems

The paper deals with a novel method, self-adjustable fuzzy sliding mode control, of a squirrel cage induction motor drive systems with a voltage source inverter. According to the principle of fuzzy logic control and sliding mode control, the theory of this new fuzzy sliding mode control is presented and a mathematical description for induction motor is derived. The sliding mode control is used to achieve robust performance against parameter variations and external disturbances. In order to reduce or overcome the system chattering owing to sliding mode control, a fuzzy control law is employed to draw the system state variables into a pre-specified bounds of sliding mode surface, and the stator voltage of a induction motor is designed to be the control variable in accordance with the inverter. Furthermore, an experimental device is set up. The experimental results show the good robustness and self-adaptability as well as superior dynamic-static performance of the proposed scheme.