Stability of sliding-mode current control for high performance induction motor position drives

A novel inner-loop sliding-mode current control scheme is proposed based on a nonlinear mathematical model of induction motor position drives. The parameters of position and speed controllers are taken into consideration in the inner-loop sliding-mode current control. After deriving the error dynamic equations, a rigorous stability verification for the overall system is provided. The proposed scheme is implemented by a PC-based controller. Agreement between analytical studies and experimental results confirms the validity of the proposed control system. The overall system exhibits robust stability and robust performance despite the presence of motor parameters and shaft moment of inertia variations as well as exogenous load disturbances.