A Commutation Error Correction Method for the Ironless-stator Permanent Magnet Brushless DC Motor Dual-stage Drive

A two-stage drive topology consisting of a Buck converter cascaded with a three-phase non-bridge is adopted to drive an ironless-stator permanent magnet brushless DC motor. But the commutation error due to low-resolution position sensors is still an issue with the square-wave control approach. To solve this problem, a commutation error correction method based on the terminal voltage of motor for the ironless-stator permanent magnet brushless DC motor dual-stage drive is designed. Firstly, the monotonic relationship between terminal voltage and commutation error in different error cases is firstly analyzed. Then the PI controller based commutation error estimator is designed to compensate the commutation error in real time. Finally, experiments are carried out to verify the feasibility and effectiveness of the method. Experimental results show that the error compensation controller can converge quickly and achieve the purpose of commutation error compensation.