High-order terminal sliding mode control for induction motors based on current decoupling

For improvement of the performance of the speed control system of induction motors, a high-order nonsingular terminal sliding mode control scheme for the speed loop and the current loop was proposed. According to the scheme, nonsingular terminal sliding modes were designed to improve the response speed and precision. High-order sliding modes were adopted to obtain smooth control signals directly, eliminating the chattering phenomenon in the conventional sliding mode effectively. With respect to the speed loop, taking the inertia change and load torque disturbance into consideration, a high order sliding mode control law was designed to guarantee the robust of the system. For the current loop, the decoupling of the stator current was achieved using the voltage compensation; the dynamic performance of the current controller was improved. The simulation results show that the proposed method can eliminate the chattering phenomenon in the conventional sliding mode obviously with the high precision, and is robust to inertia change and load disturbance.