构造稳定节点的功率变流器共模干扰抑制技术

Constructing stable nodes to suppress common-mode EMI for power converters

本文提出了一种抑制功率变流器的共模电磁干扰(EMI)的技术方法,并以Boost变流器为例,对所提出的方法进行了深入分析。由于电路中高电压变化率(dv/dt)的动态节点是共模传导EMI产生的主要源头,本文通过调整Boost电感的PCB布局与采用共阳极二极管的方法,在电路中构造稳定节点,对共模传导EMI进行了有效的消除。理论分析与实验结果都很好地证明了该方法的有效性。此外,该方法还可推广至Buck、Buck-Boost、Flyback、PFC等变流器电路。

In this paper,a simple approach to suppress common mode conducted electromagnetic interference（EMI） is proposed.The method is explained in detail with Boost converter adopted as a typical example.Most of common mode conducted EMI due to the high dv /dt nodes in the converter can be suppressed by constructing stable potential nodes（dv /dt almost zero） in the circuit,which is implemented by changing placement of the boost induc-tor and using the common-anode diode instead of the common-cathode one.It is verified by theoretical analysis and experimental results that this method is effective and applicable without much added cost.Also,this method can be easily transferred and used in other converters,such as buck,buck-boost,flyback and PFC circuits etc.