BP Neural Network Control Method of DFIG under Improved Double Loop Unbalanced Voltage.

To prevent the phenomenon of wind turbine off grid caused by grid voltage drop, the design of BP neural network is used to improve the flexibility of voltage control link, and then an improved double loop unbalanced voltage control scheme is proposed. According to the control demand and the network side model, two control objectives are designed and the corresponding current instructions are derived. To simplify the control structure, we can combine with the improved Proportion Resonant (PR) controller to change the coordinate of its current command value, so as to realize the control of the current part. An improved double loop network side control system is constructed to solve the problem of excessive fluctuation of voltage and the negative sequence component of AC current during low voltage ride through (LVRT). Finally, Modeling and simulation results using MATLAB/ Simulink software are presented to show the proposed method is effective and feasible.