摘  要：分析了无刷直流电机两两导通控制下的不同PWM调制方式，推导出不同PWM调制方式下电机稳态运行时相电流和电磁转矩的计算公式，并得出在单管PWM调制方式下有效转矩比双管PWM调制方式下大的结论，这对于PWM调制方式应用于不同场合和进一步研究转矩脉动的抑制提供了理论依据。实验结果证实了所提出的理论的正确性。
关键词：无刷直流电机；脉宽调制；电磁转矩；占空比

Abstract: This paper analyzed different PWM modes for BLDCM with six-step commutation.The mathematics expressions of phase current and electromagnetic torque were deduced according to different PWM modes.Therefore,obtained the method that the electromagnetic torque in single PWM mode is larger than in double PWM mode,which provide the theoretical basis for both application of various PWM modes and torque ripple suppression scheme.The experimental results prove the proposed theory is correct and feasible.
Key Words: Brushless DC motor;Pulse width modulation;Electromagnetic torque;Duty cycle