光伏逆变器辐射EMI噪声机理与抑制方法

摘要

Due to the radiated emission generated by PV inverter,the radiated noise source diagnosis method is proposed based on the near field measurement and wave impedance.The mechanism of radiation noise and its transmission path are analyzed,which caused by high power line crosstalk and transmission impedance loss.The radiated electromagnetic interference (EMI) noise suppression scheme is designed based on the crosstalk choke,full capacitance filter and cable terminal matching circuit.The experimental results show that the radiated EMI noise mechanism of a certain type of photovoltaic inverter can be analyzed effectively.The radiated EMI noise can be reduced 37 dBpV/m,and pass GB 9254 class A,thus provide the theoretical basis and experimental guidance for the electromagnetic compatibility design of PV inverter.%针对光伏逆变器产生的辐射电磁干扰(EMI)噪声,提出了基于近场测试和近场波阻抗的辐射噪声源诊断方法;分析了因大功率电力线串扰和传输阻抗失配引起的辐射噪声机理,以及噪声传输路径;设计基于串扰扼流圈、全电容滤波器和线缆终端匹配电路的辐射EMI噪声抑制方案.实验结果表明,该方法能有效分析某型光伏逆变器的辐射噪声机理,其辐射EMI噪声可降低37 dBμV/m,满足GB 9254 Class A限值要求,从而为光伏逆变器的电磁兼容设计提供理论依据和实验指导.