Speed and position observer of DFIG based on rotor current vector angle deviation

By further study on the previous position-observing schemes for doubly fed induction generators (DFIGs), an improved observing scheme based on rotor current vector angle deviation (RCVAD) is proposed. In contrast to stator-flux-based or rotor-current-based model reference adaptive system (MRAS) position observing schemes, the RCVAD-based observer has good characteristics of linearity, and its forward control gain is independent of DFIG rotor current value. Consequently, the DFIG sensorless control system has better dynamic performances. Simulations on a 2 MW DFIG validate the correctness of the proposed sensorless control strategy, and its preferable dynamic performances are confirmed by comparing with the rotor current-based MRAS position observer. This work is supported by the Project of the National Eleventh-Five Year Research Programs of China (No.2006BAA01A18).