Sliding-mode controlled induction motor drive using gain-adaptive phase-locked loop speed control

This paper presents a speed control system for induction motor drives. Sliding mode control is employed to provide quick torque characteristics with robustness to motor parameter variations. Excellent steady-state speed regulation and fast transient response are obtained by dual-mode control including phase-locked loop (PLL) technique and conventional closed-loop control. A loop-gain adaptation scheme is also developed using MRAS theory to suppress the torque disturbance effect on motor speed. The proposed system combines the precise speed regulation of PLL technique and the robustness of sliding mode control, with the insensitivity to disturbance by loop-gain adaptation. Simulation results verified the validity of the proposed system