Study of Integrated Vector Control for Brushless Doubly-Fed Machine

The modeling and controlling methods of Brushless Doubly-Fed Machine (BDFM) are more complex than those of traditional machines due to its special structure and operating mechanism. In this paper, BDFM dynamic mathematical model at synchronous speed rotating dq-axis coordinate is studied, and the vector control strategy is optimized by using current integrated vector. This vector control strategy does not need to calculate the rotor flux, reduces the dependence on the rotor parameters and can achieve accurate speed control by given speed and vector angle. And then, saturable parameter or variable parameter PI controller are adopted respectively, and compared with the traditional PI controller. The results show that the former two controllers can effectively improve the dynamic response of BDFM. Furthermore, the vector angle optimization by gradient descent method can effectively adjust the reactive power of BDFM and improve the power factor of the speed control system. Finally, the correctness of the theoretical analysis is verified by MATLAB/Simulink simulation.