摘要
针对无刷直流电机换相时产生转矩脉动给系统带来的不利影响,提出了一种无位置传感器无刷直流电机换相时抑制转矩脉动的三相PWM调制技术。利用反电势过零点法确定无刷直流电机转子位置信息从而获知电机转速。在换相开始后通过检测与功率管并联支路电流续流情况确定三相PWM调制时间。通过简单的比较电路实现了反电势过零点与换相期间的电流续流情况检测,与已有方法相比,节省了系统资源,提高了系统可靠性,且无需电机准确参数。实验结果表明:在无位置传感器情况下,无刷直流电机在换相期间转矩脉动得到了明显抑制。
Aiming at the problem that torque ripple happens during the commutation of BLDCM, which brings bad effect to the system, this paper presents a three-phase pulse width modulation （PWM） technique to reduce the com- mutation torque ripple of brushless de motor （BLDCM）. Compared with existing approaches ,the proposed technique does not require any torque observer and calculating commutation interval that is sensitive to motor parameters and requires much calculation time. Back-EMF zero-crossing method is used to determine the rotor position of the BLDCM and then the motor rotation speed is obtained. When the commutation starts, by detecting the current continuity in the branch parallel with the power transistors, the 3 phase PWM modulation time is determined. The back-EMF zero- crossing signal and current continuity in the commutation interval are detected using a detection circuit that consists of simple comparator. Compared with existing methods, the proposed method saves system resource, improves system reliability and does not need accurate motor parameters. The experimental results show that the commutation torque ripple of BLDCM without position sensor is significantly reduced using the presented PWM technique.
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2013年第6期1285-1292,共8页
Chinese Journal of Scientific Instrument
基金
湖南省自然科学基金(12JJ3042
10JJ3066)资助项目
关键词
无刷直流电机
换相转矩脉动
反电势过零点
换相区间
brushless dc motor （BLDCM）
commutation torque ripple
back-EMF zero-crossing
commutation interval
