Research on idle load grid-connection Control strategy for double-fed induction generator (DFIG) based on Direct Power Control

Traditional wind power generation grid-connected methods have a phenomenon of high stator current. Vector Control strategy of grid connection makes it improved. But Vector Control strategy of DFIG depends highly on the parameters. In order to get a flexible grid-connection and better robustness, this paper considers the Direct Power Control (DPC) technique which is used in doubly fed induction generator (DFIG). This approach uses instantaneous reactive power theory of three-phase circuits to the DFIG control. Improved DPC idle load grid-connected control strategy based on grid voltage orientation is proposed. Good performance is achieved during the cutting-in grid. In this paper DPC is used in the steady state to control both active power and reactive power. Based on theoretic analysis the modes of idle load grid-connection and running in ready state are established. The test results validate the grid-connection mode is a good approach for DFIG.