电动汽车共模电流传导特性的研究

在电动汽车中，沿车辆底盘和电缆传导的共摸电流是产生电磁传导干扰和共模辐射的重要原因。本文针对电动汽车中主要电磁干扰源的BOOST电源变换器，建立了电磁干扰源和共模电流传导路径的等效电路模型，指出在电缆中传导的共模电流决定于电缆一底盘的阻抗特性。电缆-底盘阻抗的传输线模型分析表明，该阻抗呈容抗、串联谐振、感抗和并联谐振交替出现的特征，使共模电流的各频率分量具有不同的沿电缆分布特性。共模电流的解析结果和试验测量结果基本吻合。为了抑制共摸电流，提出了共模电感的合理布置和取值范围。

Characteristics of common-mode conducted current in electric vehicle

Common-mode current conducted through chassis and cables is the main source of electromagnetic interference(EMI) in an electric vehicle.In this paper,equivalent circuit models of the common-mode current for its generation and propagation are presented,showing that the common-mode current is determined by the impedance between cables and chassis.The impedance is further analyzed on the basis of transmission line model with the results of the characteristics of capacitive,serial resonance,inductive and parallel resonance in turn.It causes different distribution of common-mode current with different frequency along the cable.The analytical result is consistent with the measurement of common-mode current along the cable.Furthermore,to reduce the common-mode current,desirable position and value of common-mode inductance are proposed.