Control method of a doubly-fed induction generator with automatic grid synchronization

In order to transmit energy generated through the stator winding of a doubly-fed induction generator, we need to synchronize the generated voltage vector with the grid voltage vector. However, the existing synchronization method works only when the encoder is installed at a specific position and equivalent constant is precise. To solve this problem, the present study proposed a new synchronization method and a way of applying the method to existing doubly-fed induction generator control algorithm. The validity of the proposed method was tested using a prototype converter for the control of a 1.5 MW-class doubly-fed induction generator