摘要：PWM调制方式的不同导致电流回路及续流回路不同，从而在功率管损耗、转矩脉动、电机控制及起动性能方面都会产生不同的影响。本文通过对导通相和非导通相的电流续流回路进行分析，得出了不同的调制方式对电枢电流和电磁转矩的影响也是不同的，并计算出了两类调制方式占空比之间的关系。从而分析出了不同PWM调制方式对电机起动性能和调速控制的影响。通过仿真及实验平台验证了结论的正确性。
关键词：无刷直流电机；PWM调制方式；续流回路

Abstract: The different PWM modulation modes result in different current loops and freewheeling loops, which can have different effects on power loss, torque ripple, motor control and startup performance.In this paper,bying analyzing freewheeling circuit through the conduction phase and nonconduction phase, made the conclusion that the influence of the different modulation modes on the armature current and the electromagnetic torque was also different,and the relationship between the duty ratio of the two kinds of modulation modes was calculated. The influence of different PWM modulation methods on moter starting performance and speed control was analyzed.Simulation and experimental results show that the conclusion is right.
Key words: BLDC; PWM modulation; freewheeling loop