永磁无刷直流电机伺服系统全数字化设计

基于DSP的全数字化无刷直流电机伺服系统,由包括DSP和片外存储器的以TMS320F240组成的小系统,及反馈信号采集模块2部分组成.系统原理是:三相交流输入经整流、稳压后为逆变电路提供直流电源,逆变电路所需的触发信号则由DSP提供,输出占空比可调的PWM信号通过调整的宽度控制功率管的开关时间,实现对无刷电机的控制.其数学模型的建立条件为电动机的气隙磁场沿气隙方波分布、绕组通电时磁通忽略不计、功率管压降为恒值、各相绕组对称.伺服系统采用内环为电流环,外为速度环,最外为位置环的三环串级控制结构.运行结果表明,采用这种控制方案可使系统取得良好的控制效果.

The Full-Digital Design of Servo System BLDC Motor

The servo system for full-digital BLDC motor consists of DSP, memory subsystem based on TMS320F240 and the module for feedback signal acquisition. After three-phase AC supply input was rectified, became DC power supply and then it was sent to counter-circuit. The striking signal that counter-circuit need was provided by DSP, and then adjustable PWM signal was outputted, the on/off time of power tube was controlled with adjusting the width of PWM signal, so, the control for BLDC motor was realized. The condition of establishing math model is that gas-gap magnetic field of motor distributed along gas-gap square-wave, the magnetic flux was ignored when current passed winding, the voltage of power tube was dropped to constant value, the winding of each phase was symmetrical. 3-ring serial control structure with current ring, speed ring and position ring was adopted in the servo system. The experiment result shows that excellent control effect of the servo system was obtained with the control scheme.