摘  要：通过分析反电动势三次谐波信号与无刷直流电机换向之间的关系，构建基于反电动势三次谐波检测法无位置传感器的无刷直流电机的控制系统。主要研究了三次谐波信号控制电机的换向逻辑算法，通过Simulink中的计数器(Counter)模块实现电机的换向算法，使得系统仿真更加快速。同时，该系统还加入了转速的PID闭环控制及PWM模块，使其结果分析更加准确。在Simulink中对整个系统进行仿真，结果表明，该系统理论上可行，且系统仿真快速性较好，为后续实际应用提供了一定的参考价值。
关键词：无刷直流电机；三次谐波；无位置传感器；Simulink；PID

Abstract:  Based on the analysis of the connection of the third harmonic component (THC) of the induced electromotive force (EMF) and the logic of commutation, the brushless DC motor sensorless control system based on the THC was build. In this paper, the logic of commutation was designed. Commutating with counter model made the system quick. At the same time, the PID and PWM model were increased to optimize the model. The results simulated in Simulation prove the feasibility and quickness of system, and provide a little value to the application in practice.
Key words:  brushless DC motor; the third harmonic component; sensorless; Simulink; PID