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.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
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)
关键词
反电动势法
端电压
过零点检测
换相
无刷直流电机
back electromotive force method
terminal voltage
zero crossing point detection
commutation
brushless direct current machine
