Sensorless Control of Stand-alone BDFIG With Compensation From Rotor Speed Observer

Brushless double-fed induction generator (BDFIG) is the upgrade of conventional double-fed induction generator (DFIG) for needless of the brush and slip ring. It can be used for ship shaft power generator system, in which the BDFIG mainly works at stand-alone state. The encoderless operation can enhance the system's reliability and reduce the cost. This paper proposes a modified sensorless control method of BDFIG which can realize precise phase angle control. That can be important when it is used for connecting the machine to the grid quickly and reliably. A rotor speed observer (RSO) is used to supply the feed-forward compensation. Experimental results are given to prove the effectiveness of proposed method.