摘要
EMI滤波器是抑制传导噪声的重要手段之一,尤其是高性能的EMI滤波器的应用,对电力电子设备的干扰具有很好的抑制作用。基于传输线理论得到并联传输线的共模及差模参数,通过推导和测试得到噪声源阻抗、负载阻抗及其等效结构,求解得到基于阻抗法的插入损耗(IL)。但是,在高频条件下,EMI滤波器及传输线不仅存在自寄生参数,还存在互寄生参数,这些互寄生参数很难通过阻抗法来等效。本文在传输线等效共模与差模参数频率特性的基础上,根据传输线理论得到噪声源阻抗及负载阻抗;以共模滤波器为例,基于阻抗法预测滤波器对噪声的衰减能力,并与实际测试值进行比较。然而,由于阻抗法不能很好地预测高频条件下的噪声衰减,本文以波的"入射与反射"为核心,进一步提出一种利用S参数来预测阻抗不匹配条件下噪声衰减的方法,研究表明,散射参数法由于考虑了元件间的互寄生参数,具有更好的高频性能。
Electromagnetic interference (EMI) filter is an important component to suppress theconducted EMI noise, especially the EMI filter with high performance. Based on the transmission linetheory, the common mode (CM) parameters and differential mode (DM) parameters of paralleltransmission lines are obtained, and the source and load impedances are received through calculationand test. Furthermore, the insertion loss (IL) can be calculated by the impedance method. However, inthe high frequency, the parameters of EMI filter and transmission line involve not only theself-parasitic parameters but also the mutual parasitic parameters. These mutual parasitic parametersare very difficult to calculate or be equivalent by the impedance method. Therefore, the parameters ofCM and DM filters with transmission line are explored. Then, according to the transmission line theory,the noise source and load impedance are calculated. Taken CM filter as an example, the attenuation ofnoise is predicted by the impedance method, and is compared with the actual test value. However, theprediction on attenuation of noise is inaccurate at high frequency. Thus, this paper further presents amethod (S parameter) to predict the attenuation accurately under the conditions of impedance mismatch,where the key of this method is the incident and reflected waves. It is shown that due to the consideration of the interaction among the parasitic elements, the S-parameter method has betterhigh-frequency performance.
作者
王世山
龚敏
宋峥
Wang Shishan;Gong Min;Song Zheng(Jiangsu Key Laboratory of New Energy Generation and Power Conversion Nanjing University of Aeronautics and Astronautics Nanjing 210016 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2016年第18期66-74,共9页
Transactions of China Electrotechnical Society
基金
国家自然科学基金(51177071)
台达环境与教育基金会<电力电子科教发展计划>(DREK2013004)
江苏高校优势学科建设工程项目
南京航空航天大学研究生创新基地(实验室)开放基金(kfjj201412)
中央高校基本科研业务费专项资金资助项目
