一种无传感器BLDCM数字化控制系统设计

Design on the Digital Control System for Sensorless BLDCM

介绍了基于ST公司推出的电机控制专用芯片ST7MC的电机数字控制系统,系统中除了应用反电势法所必需的功率驱动电路、反电动势和电流反馈电路等硬件外,完全由软件算法实现了电机开环换相启动,反电势过零判断,同时在自动转换状态通过反电动势过零点软延时实现自动换相,并通过换相后延时反电动势检测达到换相软滤波的作用,从而达到整个控制系统数字化控制的目的,节省了成本,增强了系统的抗干扰能力。经调试检验本控制系统具有良好的控制性能。

A digital control system based on motor control chip ST7MC produced by ST corporation was introduced. In addition to the driving electric circuit, back-EMF and current detection feedback circuit required by the back-EMF method, realized the motor at open loop and phase converting when motor started and back-EMF zero-crossing detection by the software way. And at the mean time, under automatic control state, convert phase is carried out by the software postponing strategy of the back-EMF zero-crossing, and the wave is filtered at phase converting twinkling by the postponing strategy of the detection neglects. Thus it is realized that the whole control system is digital, the cost is saved, and the anti-interference ability of the system is strengthened. Experimental results indicate that this system has a high performance.