Speed Sensorless Control in Direct-drive Permanent Magnet Synchronous Generator System

The sensorless vector control has been widely applied in Permanent Magnet Synchronous Motor(PMSM) for the micro turbine generation system (MTGS). Speed Adaptive Full Order Observer(AFOB) presents a high accuracy for speed and position estimation. This paper proposes a unified feedback gain matrix design method, which adopts a left-shifting and zooming design criteria compare to the poles of motor. For speed sensorless generator system, the initial speed is unknown because the motor is rotating by micro turbine, it would be problematic to achieve smooth resumption of normal operation if the starting process is not deliberately designed. To solve this problem, a restart scheme based on AFOB is proposed in this paper. Finally, the effectiveness of the proposed method is validated by the simulation and experiment results in direct-drive generation system.