LQR-based stator field oriented control for the induction motor drives

This paper introduces a new approach to the stator field oriented control of the induction motor (IM) drives. The scheme is based on the linear quadratic regulator (LQR) theory with preview. A state model suitable for voltage control is derived in the synchronous frame using vector method. An augmented error system is formulated to cure the adverse phenomena caused by modeling errors and disturbances. The synthesized controller stabilizes this error system asymptotically, achieving robust speed control and orientation of the stator flux vector. Furthermore, the speed reference and load torque signals are utilized via a supplementary preview control loop to improve the transient response of the controlled drive. Simulation and experimental results are provided to confirm the effectiveness of the proposed method.