IMPROVED LQR-BASED CONTROL APPROACH FOR HIGH PERFORMANCE INDUCTION MOTOR DRIVES

An improved LQR-based control approach with an aim to high performance control systems for induction motor (IM) drives is presented. The proposed algorithm incorporates dynamic separable first order filters with appropriate time constants and integral actions to uncouple the flux and the torque/speed of an IM and provide the same performance as achieved by a separately excited DC machine. The proposed approach leads to optimal feedback gains for the control loops and ensures a decoupling between the system outputs while guaranteeing reduced stationary errors and avoiding inadmissible amplitude of the control signals. Simplicity of the overall scheme, minimization of the required energy and the elimination of the need for gain tuning required by the classical Field Oriented Control (FOC) are the main positive features of the proposed approach. The performances of the proposed approach are analysed in this paper, then compared to those obtained by the classical FOC.