考虑换相时无刷直流电机脉宽调制方法研究  

Research on the Pulse-Width Modulation Methods of Brushless DC Motor Taking Consideration of Commutation

作　　者：揭贵生[1] 马伟明[1] 

机构地区：[1]海军工程大学电力电子技术研究所,武汉430033

出　　处：《电工技术学报》2005年第9期66-71,共6页Transactions of China Electrotechnical Society

基　　金：高等学校优秀青年教师教学科研奖励计划资助项目(文教司[2001]183)

摘　　要：对于转子永磁磁场为梯形波分布的三相BLDCM,首先分析了采用两两通电方式时电机电流及换相转矩波动的变化特点,然后从理论上给出了低速时基于H_pwm-L_on方式的一种改进的换相转矩脉动补偿方法;重点结合高速多极BLDCM的特点,在此基础上提出了改进的电压滞环PWM方法,以此来尽可能保持换相期间关断相与接入相的电流平衡,维持电机电磁功率的恒定,从而减小换相过程对转矩脉动和系统转速跟踪性能的影响。仿真和实验结果表明:采用基于H_pwm-L_on方式的补偿方法,其补偿作用有限,且续流时间难以准确计算,工程实现较为困难;采用这种改进的电压滞环PWM方法,电机电流和电磁功率在换相期间的波动小,在工程实用和有效抑制换相转矩波动方面有较大的优势,比较适合高速多极BLDCM控制系统。The researching object of this paper is the ideal three phase trapezoidal brushless DC motor. At first, the changing characteristics of the motor currents and torque ripple induced by the commutation are analyzed when the method of two-phase energized is adopted, then a improved compensation measurement of the torque ripple using the H_pwm-L_on method at low speed is deduced theoretically. Combined with the characteristics of the high speed multi-pole BLDCM, a improved voltage hysteresis-band PWM method integrated with the overlapping commutation is put forward to keep the current balance as good as possible between the increasing speed of the energized phase＇s current and the deceasing speed of the disenergized phase＇s current. It can make the electro-magnetic power invariable and reduce the commutation process＇s influences on the torque ripple and the speed tracking capability the system. The simulation and experimental results show that the compensation effect of the torque ripple is limited and it is difficult to calculate the freewheel time accurately using the H_pwm-L_on method; while the new controlling method is effective on engineering application and the suppress of the torque ripple, so it is preferable for the controlling system of the high speed multi-pole BLDCM.

关 键 词：无刷直流电机 换相续流 脉宽调制 滞环电流控制 

分 类 号：TM33[电气工程—电机]