无刷直流电机正弦波控制及其在电动自行车中的应用

摘要

Brushless DC motor is typically controlled by the square wave,the algorithm is simple,easy to control,but its weakness is torque ripple and high noise.Based on the analysis of conventional three-phase SPWM,a two-phase SPWM control algorithm of minimum switching loss is brought forward,and the electric bicycle control system is designed based on micro-controller μPD79F9211 which is used as a control chip.The rotor position of the brushless DC motor is determined with the three-phase Hall signal.Through the speed closed-loop control,current-limited control and two-phase SPWM control algorithm of minimum switching loss,a simple and efficient sine wave control system of the electric bicycle is realized.Practice has proved that compaed with the square wave control in electric bicycle,this system reduces torque ripple,lower noise in start-up and operation process.The resuhs show that the control system is feasible and has a good price.At present,the system has been achieved and successfully used in electric bicycle system.%传统的无刷直流电机一般都采用方波控制,算法简单、易于控制,但缺点是转矩脉动较大、噪声高.在分析常规三相SPWM的基础上,提出采用一种开关损耗最小的两相SPWM控制算法,并设计了基于微控制器μPD79 F9211的电动自行车控制系统.以μPD79F9211为运动控制芯片,借助三相霍尔信号来确定无刷直流电机的转子位置,通过转速闭环控制、电流限流控制和开关损耗最小的两相SPWM控制算法,实现了一种简单而高效的电动自行车正弦波控制方案.实践证明,相比目前在电动自行车控制领域采用的方波控制方案,该方案转矩脉动减少,启动和运行噪声更低.实验结果表明上述控制系统方案可行,具有良好的性价比.目前,该系统已经实现并成功应用于电动自行车系统中.