将工作与噪声电流分离的母线型滤波器单元开发

Development of Bas-Bar EMI Filter Unit with Function of Separating Working and Noise Current

基于"集肤"与"邻近"效应开发一种可将"工作"与"噪声"电流分离的电磁干扰(Electromagnetic interference,EMI)滤波器。若在所开发的单元外侧制备具有一定厚度、对噪声可实现有效衰减的导体,由于集肤效应,该单元可实现对共模高频噪声电流的有效耗散;若在单元的内侧制备相同材料的导体,由于邻近效应,该单元可实现对差模高频噪声电流的有效耗散。采用合适的电气连接方式,滤波器单元可以将"噪声"电流和"工作"电流分离,从而对高频噪声电流进行有效的抑制,而对"工作"电流几乎衰减很小。文中基于有限元法,建立了该类单元的时谐场模型,仿真了单元导体中的电流密度分布,提取了其交流电阻系数,定量描述了该类单元对噪声的耗散能力。

An electromagnetic interference（EMI） filter with the function of separating working and noise current is proposed based on the ＂skin effect＂ and ＂proximity effect＂. By plating a high loss conductor with a certain thickness to the outside of the unit, the common mode （CM） noise can be dissipated due to the skin effect. While by plating the conductor to the inside of the unit, the differential mode （DM） noise can be dissipated due to the proximity effect. By proper electrical connection, the ＂noise＂ current and the ＂working＂ current can be separated, thus achieving the suppressed high frequency noise current and almost lossless working current. Based on the finite element method （FEM）, the harmonic field model is established, the current density distribution is simulated, the AC resistance coefficient is ex- tracted, and the quantified analysis of the dissipation capability is included.