Vector control of brushless doubly-fed induction machines based on highly efficient nonlinear controllers

Recent advancement in design and control of brushless doubly-fed induction machine (BDFIM) has substantially improved its performance. In this article, two high efficient vector control schemes are proposed for the BDFIM drive based on Lyapunov nonlinear techniques. The first scheme aims for speed control with a one-level structure without an inner loop controller, and the rotor speed error is delivered to a backstepping speed controller. The second scheme has a two-level structure with a backstepping controller and a model reference controller for torque and speed control, respectively. To enhance the performance, the proposed control schemes are based on a novel maximum torque per Ampere (MTPA) control strategy, and their stability is proven by Lyapunov control theory. The proposed controllers are validated experimentally on a 3-kW prototype D132-BDFIM by a TMS320F2833 microcontroller synchronized with a personal computer, and show superior performance over optimal proportional-integral controllers under changing reference speed and load torque.