Study on the direct voltage control strategy of Brushless Doubly-Fed independent power generation system

Aiming at the variable-speed constant-frequency and constant-voltage control strategy of Brushless Doubly-Fed Generator (BDFG) independent operation, stator double synchronous speed mathematical model was established through coordinate transformation of the mechanical rotor speed d-q coordinate model. Besides to improve the robustness and achieve online PID parameters adjustment when the generator state changed, the expert PID regulator was introduced. Finally the direct voltage control strategy based on the flux oriented control theory and expert PID regulator was deduced. It can be seen that the system can control the output power according to the load, and realize the variable-speed constant-frequency and constant-voltage electricity generation. The effectiveness of the proposed control strategy is verified by simulation.