The sensorless control technology based on rotor initial position detection

This paper studies on sensorless control technology applied in permanent magnet synchronous motor. With respect to the problems in existing test method for initial position, the paper starts with the technology to observe flux linkage and detect initial position used in sensorless control technology in direct-drive permanent magnet wind driven generator, and on this base, a theory of detecting rotor initial position by mixing two-phase with three-phase for breakover is put forward. After simulation analysis, the correctness is verified, then on-site experiments are conducted on direct-drive permanent magnet wind driven generator twin trawling experimental platform provided by some cooperative institutions, with the direct-drive permanent magnet wind driven generator set on a condition with slow-speed of revolution. It turns out that the method of mixing two-phase with three-phase for breakover could not onlydetect the rotor initial position quickly and effectively, but also possibly control the error within ±15° electrical angle. At the same time, it is applicable for the low cost, easy to implement, which is capable of meeting the requirements to start a direct-drive permanent magnet wind driven generator.