The Improvement of Position-Sensorless Field-Oriented Control Start-up Based on Extended-Electromotive Force for Permanent-Magnet-Synchronous-Motor

In the last decade, the trend in major position-sensorless research on permanent magnet synchronous motor drives has been to improve the performance of sensorless control. In a previous study, we proposed a position estimation method available for the full-speed range with a single Extended-Electromotive Force(EEMF) observer, simplifying the implementation of position-sensorless control. Unfortunately, a certain amount of time must be ensured for polarity determination and initial position estimation with EEMF, which affects the performance of the velocity control at start-up from the standstill state. To improve the EEMF sensorless control performance for the full-speed range, a new position-sensorless start-up method is proposed, to reduce the start-up time. The configuration of the EEMF position-sensorless control system is presented, and the principle of the proposed position-sensorless start-up method is described. The experimental results validate that the proposed method is more effective than the conventional method.