直流有刷电机传导发射特性和外置滤波电数值试验研究

摘要

Using the method of 3m EMC laboratory for a certain model of a DC motor,conduction emission characteristic and external filter circuit numerical experiments were studied.LC filter circuit is selected to study the filter effect of external circuit.The results showed that as the grounding capacitor Cx (Cx ≥ 1 uF,typical values)on the power supply lines increase,the conducted emission allowance Margin increased significantly,which enhance the effect of filter,while the low frequency wave sharp changes to be gentle.As the motor circuit capacitor Cy (Cy ≤ 15 nF,typical values)decreases,and conducted emission allowance Margin increased slowly,waveform keeps well.LC filter circuit can effectively increase the conducted emission allowance Margin value,improve EMC test limit level,according to the law of numerical experiments in Cx,Cy,the problem of conducted emission levels of different DC motors can be solved effectively.%利用3m法EMC试验室对某款直流有刷电机传导发射特性和外置滤波电路数值试验进行了研究.选定LC滤波电路作为外置电路进行滤波效果研究的结果表明:随着供电线路上的接地电容G(Cx≥1μF,典型值)的增大,传导发射余量Margin显著增加,即滤波效果增强,同时中低频段的波形急剧变平缓;随着电机回路电容Cy(Cy≤15 nF,典型值)的减小,传导发射余量Margin缓慢增加,波形保持良好.综合分析:LC滤波电路可以有效增加传导发射余量Margin的值,提升EMC试验限值等级,根据Cx、Cy的数值试验规律可以有效地解决不同直流电机的传导发射超标问题.