High Performance Speed Sensorless Induction Motor Control Research

Alternating current (AC) drive plays an important role in industry and has been used in many fields such as manufacture, drive & transportation, and pumps and so on. Induction machine is the most widely used AC machine, whose capability takes up 70%-80% of the whole electrical machine capability. But due to the complex structure of induction machine, the control of induction machine is relatively difficult. And the parameters of induction machine are easily drifted with the variation in industrial environment. The above two factors are the main reasons of deteriorating the performance of induction machine. For the speed sensors which are used to measure the speed output of induction machine reducing the reliability and increasing the cost, how to eliminate the speed sensor is a focus in last years. Based on the above causations, this paper considers the impact of the electrical characteristic on the mechanical performance, achieves decoupled control of speed and flux, solves the robustness problem of induction machine against parameter variations, and applies the control strategies in sensorless field.This paper uses nonlinear control methods to control induction machine, and utilizes speed observer to replace speed sensor simultaneously. The main works include the following nonlinear control strategies: a robust sliding-mode control strategy of a sensorless induction machine based on load torque identification; an induction motor control strategy based on full order adaptive speed observer; a sliding-mode control scheme of an induction machine based on exact state feedback linearization.Sliding-mode control has two evident advantages: the one is its robustness to parameter variations and system disturbances and the other is decoupling property to its controlled variables. The obvious drawback of sliding-mode...