Self-tuning speed controller design of vector control induction motor drives

This paper presents a design algorithm to automatically tune the speed controller of a vector control induction motor, where an equivalent control scheme is used via the torque equation. We apply the recursive least square estimation method to identify the mechanical parameters, moment of inertia and friction coefficient. Following the manipulation of pole placement, we determine the parameters of a PI type speed controller. In order to investigate the estimation results of using different analog to digital transformation methods, forward and backward rules are used. In the stage of controller design, the traditional Ziegler-Nichols algorithm and root locus design method are addressed so that the advantages of the proposed on-line tuning method can be pointed up. Finally, a PC-based experimental system is set/up to evaluate the feasibility of the proposed methods. Experimental results indicate that the proposed self-tuning algorithm can successfully improve the loading effect and has good tracking ability.