提高无刷直流电机转矩电流比的提前换相角研究

介绍了一种计算提前换相角以提高无刷直流电机转矩电流比的方法。无刷直流电机由电角度120°的方波电流所驱动,每转动60°电角度时,电机相电流必须换相一次。由于无刷直流电机绕组中的电感作用,相电流换相时会引起相位滞后且偏离理想方波电流,这些非理想特性会减少电机的转矩电流比,改进换相的时间即通过计算提前换相角对电机进行提前换相可以提高转矩电流比。实验中对额定功率20W,额定转速20000r/min的无刷直流电机进行了仿真,结果证明了所提计算方法的有效性。

Research of Advance Commutation Angle Used to Improve Torque-to-Current Ratio of Brushless DC Motor

This paper introduces al method of calculating an advance commutation angle in order to increase torque-to-current ratio of a brushless DC （BLDC） motor. The BLDC motor is driven by a square-wave current of 120 electric degrees duration, and the phase current must be commuted every 60 electrical degrees of rotation. Owing to the inductance level of the BLDC winding process, the commutation lead to a phase lag and deviations from the ideal square-wave current form. These non-ideal characteristics reduce torque-to-current ratio. Advancing the commutation time can improve torque-to-current ratio, i.e. the motor is commutated in advance by calculating advance commutation angle. A rated power of 20W and rated speed of 20000RPM of BLDC motor is simulated by experiment, and the results indicate that the calculating method is effective.