The Hybrid Coordinate Cutting-in Control Technology of the Doubly-fed Variable Speedand Pitch Wind-power Generator

In view of the cutting-in problems of the doubly-fed wind power generator, this paper deals with it’s control strategies in detail and proposes a coordinate cutting-in control method based on the hybrid system theory, and establishes the hierarchical control model of the doubly-fed wind power generator around the cuttingin. On the basis of the model, the model information and structure information of the system are decentralized. On the one hand, the control algorithm is designed for the continuous variable of the system with the d-axis current and q-axis current as its controlled outputs according to the estimated mechanisms and control strategies. On the other hand, the hybrid automaton is used for the state transition of the system discrete variable. Simulation results show that compared with the traditional control methods this new control method can make the d-axis current and the q-axis current of DIFG to the reference values in finite time and achieve the effective control of the rotor current. What's more important this method can not only improve the no off-grid ability during the grid-voltage fluctuation, but also prevent the rotor and rotor-side converter over current effectively. It has important actual significance and practical application value.