Sensorless High-Precision Position Correction Strategy for a 100 kW@20 000 r/min BLDC Motor With Low Stator Inductance

This paper focuses on the sensorless high-precision position correction strategy for a 100 kW@20 000 r/min brushless dc (BLdc) motor with low stator inductance (0.051 mH). Two key points related to the sensorless were studied. The one is the rotor position detection with high-frequency interference. The other one is the commutation compensation for the high-speed BLdc motor with low stator inductance in whole speed range. In order to filter out the high-frequency interference, the main factors, which that can influence the rotor position detection and the commutation accuracy were analyzed. In order to compensate the commutation error in high-precision and whole speed range, the relationship between the commutation error angle and the phase current deviation was derived. It is noted that the commutation time and the phase current error can exactly reflect the commutation error angle. Then, a novel sensorless high-precision position correction strategy based on the uncommutation current was proposed. Finally, the experiment platform based on a 100 kW@20 000 r/min BLdc motor was built, and the validity and efficiency of the proposed strategy were proved.