RPWM抑制无刷直流伺服系统传导EMI研究

Investigation of Using Random PWM to Suppress Conducted EMI of Brushless DC Motor Servo System

大功率无刷直流电机伺服系统(Brushless DC Motor Servo System,简称BLDCMSS)在航空和军事领域的应用中,面临着因斩波控制产生的传导和辐射严重而带来幅值大,频带宽的电磁干扰(EMI)问题。为了减小系统的EMI,研究了一种在特殊场合下工作,并基于DSP的10kW/270V BLDCMSS用的随机载波频率调制(RCFM)方法,即RPWM技术,分析了RPWM替代PWM后,伺服系统的传导EMI水平变化。在具体分析了基于DSP伺服系统特性的基础上,提出了3种易于实现伺服系统数字控制的RPWM方法。实验测试结果表明,RPWM能使传导EMI的幅值最大降低10dB,从而使伺服系统符合电磁兼容标准CE102。

Pulse Width Modulation （PWM） used in high power Brushless DC Motor （BEDCM） servo systems in aerospace and military produces High-amplitude and wide bandwidth high Electromagnetic Interference （EMI）.The article investigates the feasibility of using one of the Random CarTier Frequency Modulation （RCFM） methods,RPWM,in 10kW/ 270V BLDCM servo system to reduce EMI and highlights variability of the conducted EMI using RPWM instead of PWM. At the same time, three RPWM methods easy to handle in numerical servo system are glven.Experlmental results testify that the maximum magnitude of conducted EMI has been reduced by 10dB using RPWM method.So RPWM can make system easily satisfy the country standard CE102.