Stability and Dynamic Performance Improvement of Adaptive Full-Order Observers in Sensorless Induction Motor Drives

To assure the stability and dynamic performance of the sensorless induction motor drives, the design strategy of both feedback gains and adaptation gains for an adaptive full-order observer (AFO) is a necessary issue. In this paper, to accomplish both requirements, a simplified design of feedback gains of AFO is studied, and the selection method of the optimal value for feedback gains is discussed using the method of Popov hyper stability theory. For the adaptation proportional-integral (PI) gains, a novel optimization method of the adaptation PI gains is proposed to enhance the dynamic performance of the speed estimation system. With the proposed variable arguments PI, the speed estimation achieves higher adaptability. The validity of the proposed method is verified by simulation results.