典型开关电源无源组件近场耦合集总参数提取方法研究

Although the complex electromagnetic coupling effects among magnetic components, capacitors, interconnections are the very common causes for a switched mode power supply fails in conducted emission or radiated emission test, there still is a lack of a systemic and wideband effective theoretical method to quantify or predict the lumped coupling parameters by now. This present theory situation can't meet the requirements of electromagnetic compatibility prediction and optimum for a modern SMPS design anymore. Therefore，this project aims at developing a novel near field coupling lumped parameter extraction method for a DC/DC typical switched mode power supply. The lumped circuit coupling parameters, such as mutual inductance and mutual capacitance, will be systemically extracted from 3 dimension PEEC models of a SMPS through matrix mapping calculations according to port impedance eigenmode match. Then the method's error, its causes and improvement will be studied too. Firstly, the magnetic hysteresis and frequency dependent characteristics of ferrite core will be included into partial element model and then this new improvement will be used to build up the 3 dimension precise PEEC models for typical power transformer, power inductor and capacitor. Secondly, the mapping algorithm from port impedance eigen frequencies and eigen vectors of PEEC model to the lumped inductance, capacitor matrix and incidence matrix will be deduced. This algorithm then is used in parasitic and mutual parameters extraction on both passive components and the whole passive section in a SMPS. Further more, the precise and error of extracting method will be investigated. Their relationship among eigen values, the number and position of physical-nodes selected will be analyzed and error improvement methods will be developed. In a summary, a systemic near field coupling parameter extraction algorithm will be realized in this project and it will be very useful to the near field effect prediction and design of a power electronics device. Naturally, the theory results of this project will also help the near field research of other electronic equipment in both theory and applications.

开关电源内无源组件间复杂近场耦合是形成电磁干扰的重要原因，但目前近场耦合集总参数的准确宽频预测尚缺乏系统、有效的理论方法，成为开关电源电磁兼容预测和优化设计的重要阻碍。本项目基于典型DC/DC开关电源无源器件—整体多层次3D PEEC电磁模型，由端口阻抗模匹配，经物理节点合理选择和矩阵映射运算提取出宽频有效而简洁的集总互感、互容参数，分析误差并改善。研究含磁滞与频变特性的铁氧体磁芯的部分元模型，建立典型变压器、电感器及电容器准确PEEC模型；研究由PEEC模型端口阻抗特征频率、特征向量到集总电路关联矩阵和电感/电容矩阵的数学映射方法，实现无源组件及含高频环路无源部分整体的耦合与寄生参数的准确提取；考察误差分布特点，分析其与特征根及物理节点关系，研究精度提高办法。研究将实现无源组件近场耦合集总参数的理论化提取，促进开关电源近场效应预测与分析，对其它类型电力电子设备电磁兼容研究也有重要意义。

当代开关电源高功率密度的结构形式造成其内部磁性元器件、互连导线、电容器件间存在较强的磁、电耦合，利用部分元等效电路（PEEC）方法进行耦合电路参数的量化提取有着重要的学术意义和工程应用价值。本研究具体完成了PCB空芯电感与变压器的700MHz宽带PEEC电路建模和集总参数提取、含镍锌铁氧体磁芯的平面增强型磁器件与EI型磁器件的100MHz宽带PEEC建模和集总参数提取、一台DC/DC Boost开关电源内磁耦合形成的共模电磁干扰新现象的2MHz电路建模分析和改善等预定内容。项目期间，课题组也对Boost开关电源远场电磁辐射进行了研究，提出了一种“共模驱动源+不对称天线”的新型模型分析和预测方法。本研究在PEEC无源器件宽带建模、高阶模型压缩、电磁辐射机理模型方面取得了良好进展，对于实现无源组件近场耦合参数的准确量化、近场耦合电磁干扰作用的分析有着良好理论参考意义和工业应用指导价值。