电动汽车无线充电系统传导电磁干扰及其对安全性的影响

Conducted electromagnetic interference in electric vehicle wireless charging system and its effects on system safety

为了明确电动汽车(EV)无线充电系统(WCS)的传导电磁干扰(EMI)特性及其对系统安全性的影响,该文分析系统等效传导电磁干扰源,建立传导电磁干扰等效电路模型。基于实际系统参数分析传导干扰传递函数在谐波频率处的增益,研究系统额定工作状态、线圈发生较大偏移,以及整流电路工作在断续导通模式(DCM)的情况下,系统传导电磁干扰特性及其对安全性的影响,并对所建立的模型进行试验验证。结果表明:电动汽车无线充电系统线圈之间发生较大偏移及整流电路工作在断续导通模式时,会带来高频传导干扰,需要采取相应的措施进行抑制;在设计系统时应保证整流电路输入电感足够大,以避免断续导通模式带来的传导电磁干扰并提高系统电磁安全性。

The equivalent electromagnetic interference(EMI)sources were analyzed to clarify the conducted electromagnetic interference characteristics in electric vehicle(EV)wireless charging system(WCS)and its effects on system safety.WCS equivalent circuit model was established.Harmonic gains of the conducted EMI transfer functions were studied based on the actual parameter values.The experiments were carried out to investigate the conducted EMI characteristics and their effects on system safety under the conditions of system rated state,coil large misalignment,and discontinuous conduction mode(DCM)of the rectifier.The results show that coil large misalignment and rectifier DCM would bring high frequency conducted EMI,and some measures need to be taken for EMI suppression.Meanwhile,the rectifier input inductance should be big enough to avoid conducted EMI brought by rectifier DCM,for the sake of improving system safety.