Experimental sensorless vector control performance of a DFIG based on an extended Kalman filter

Doubly fed induction generators (DFIGs) are used in variable speed wind energy conversion systems. Field oriented control (FOC) of this type of generators requires the availability of a rotor position measurement or estimation. Hence, for sensorless implementations, rotor position observers have to be integrated to the control algorithm. In this paper, the observability of the DFIG is analyzed and an extended Kalman filter (EKF) is proposed as rotor position observer. The performance of the EKF is verified experimentally in a 4[kW] prototype.