基于直接反电动势法的无刷直流电机准确换相新方法  

New accurate commutation method based on direct back-EMF method for brushless DC motor

作　　者：林明耀[1,2] 周谷庆[1,2] 刘文勇[1,2] 

机构地区：[1]东南大学伺服控制技术教育部工程研究中心,南京210096 [2]东南大学电气工程学院,南京210096

出　　处：《东南大学学报（自然科学版）》2010年第1期89-94,共6页Journal of Southeast University：Natural Science Edition

基　　金：江苏省自然科学基金资助项目((BK2008306)

摘　　要：分析了上桥臂PWM调制、下桥臂恒通调制方式时的端电压波形,讨论相应的反电动势过零点检测方法.在PWM调制信号开通状态结束时刻对端电压进行采样,由软件算法确定反电动势过零点.针对电机运行时存在超前换相或滞后换相的情况,通过设置合理的延迟时间来实现最佳换相.针对实际电机存在反电动势过零点分布不均匀的情况,根据过零点间隔时间存在着周期性规律,提出一种新的延迟时间设置方法,使换相点位于相邻过零点的中间位置,实现了电机的准确换相.实验验证了所提出方法的可行性和有效性.The sensorless control drive for brushless direct current machine （BLDCM） is investigated based on direct back electromotive force （back-EMF） detection method. The terminal voltage waveform is analyzed for the H_pwm-L_on type of modulation, and the zero-crossing point detection methods are discussed. The terminal voltage is sampled at the end of pulse width modulation （PWM） onstate and the zero-crossing point is extracted from the proposed algorithm. The effects of the leading and the lagging commutation on the operation performance are analyzed, and the condition of the opti- mal commutation is presented. Because the zero-crossing points distribute asymmetrically in the BLDCM, a new setting method of delay time is suggested and the more accurate commutations are achieved. The experiment results have verified the feasibility and validity of the proposed method.

关 键 词：反电动势法 端电压 过零点检测 换相 无刷直流电机 

分 类 号：TM351[电气工程—电机]