Sensorless vector control operation of a PMSM by rotating high-frequency voltage injection approach

Based on analyzing the mathematic model of a permanent magnet synchronous motor (PMSM) excited by a set of high-frequency voltage signals, a novel rotor position self-estimation method was investigated in this paper. The rotating high-frequency voltage-signal injection method, the heterodyning algorithm for the extraction of the high-frequency negative-sequence current, which contains rotor space-position information, and the structure of the rotor position tracking observer were all discussed. Further more, the experimental investigation for the complete signal processing of the rotor space-saliency detection by the rotating high-frequency voltage-signal injection was conducted with a inset-type PMSM and the sensorless vector control operation was realized with success as well. The experimental results indicate that the rotor position self-estimation scheme, based on the rotor saliency-tracking approach, is capable of precisely estimating the rotor space-position and speed and the sensorless vector control operation of the PMSM using the proposed rotor position estimation method possesses acceptable static and dynamic performance.