| AC motors are widely used in industry due to their reliability, ruggedness and relatively low cost. They are composed of triple parts (namely, electric, magnetic and mechanic), and represent a complex multivariable nonlinear problem. The thesis mainly deals with research on the high performance speed control of AC motors (induction motors (IM) and permanent magnetic synchronous motors (PMSM)).Based on their mathematical descriptions under different reference frames, the thesis first proves passivity of their electric-magnetic subsystems, and then respectively presents passivity-based speed control schemes for IMs and PMSMs with and without speed sensor. The thesis shows that both the speed and the torque can asymptotically stably track their reference values without using magnet observers.In the Matlab/Simulink environment, the thesis respectively establishes the corresponding simulation models for components (IM, PMSM, inverter, and controller) and speed control systems. Simulation experiments show that the schemes presented have good tracking performance even in varying loads, and have good robustness for uncertain rotor resistance.The thesis discusses the problems arising in the study period, and indicates some further work on speed control of AC motors. |
