Improved rotor position estimation for permanent magnet synchronous machines based on hall-effect sensors

In order to replace the traditional high-resolution position sensors in the permanent-magnet synchronous machines (PMSM), the digital Hall-effect sensors are commonly employed to estimate the rotor position and speed. However, the traditional estimated method based on the average speed results in position error due to the six discrete Hall-effect signals in one resolution at low speed, which will degrades its performance. To compensate the estimated rotor position and speed errors, the Hall-based position observer combined with a non-smooth feedback phase-locked loop (NSFP) is introduced in this paper, which can achieve continuous rotor position and speed signals at all speed range. The static and dynamic performance of the estimation algorithm is validated by experiments on one prototype.