提高开关电源抗EFT／B干扰性能的研究

Study on Improving the Immunity of SMPS to EFT/B Tests

提高电力系统二次设备抗电磁干扰能力对于保证电力系统的稳定运行至关重要。作为二次设备的心脏,开关电源的抗干扰能力是关键之一。文中研究了二次设备开关电源进行电快速瞬变脉冲群骚扰(EFT／B)试验时共模和差模噪声的传播路径,在此基础上提出了2种方法以减小耦合到负载上的噪声电压。实验证明,文中提出的这些提高开关电源抗EFT／B干扰的方法具有明显的效果。

Improving the immunity of the secondary equipment in a power system to electromagnetic interference （EMI） is vitally important to guarantee the normal operation of the power system. Usually the power sources of the secondary equipment are provided with switched-mode power supply （SMPS）, and thus the immunity of SMPS to EMI is one of the key issues of the secondary equipment to stand against EMI. The spread paths of common mode （CM） and differential mode （DM） noises in an SMPS under EFT/B test are studied and discussed. Hereby two methods to attenuate the noises coupled to the load are presented. The effectiveness of the methods proposed to improve the immunity of SMPS to EFT/B test is then verified by experiments.