高频电子电路用圆形截面环形磁心中电磁场的分布  

Electrical and magnetic field distributions in toroidal core with circular cross section for high-frequency electronic circuits

作　　者：田莉[1] 田铭兴[1] 

机构地区：[1]兰州交通大学自动化与电气工程学院,甘肃兰州730070

出　　处：《电工电能新技术》2014年第10期33-38,共6页Advanced Technology of Electrical Engineering and Energy

基　　金：国家自然科学基金资助项目(51167009)

摘　　要：为了研究当线圈缠绕于高频电子电路用圆形截面环形磁心某一段,考虑漏磁时磁心内部电磁场的分布,根据磁通连续性原理及镜像法,将绕有一个线圈的环形磁心内电磁场的分布问题,转化为绕有无穷多个线圈的无限长直磁心在其中一段磁心内的电磁场分布问题。基于麦克斯韦方程组和叠加原理,推导了环形磁心内电场强度和磁场强度的单重级数式解析计算公式。基于电场强度的计算公式,得到了涡流损耗的计算公式,与基于线圈自阻抗得到的涡流损耗计算公式进行对比,二者的计算结果吻合良好,证明了本文分析方法及所得公式的正确性。电场强度和磁场强度的计算结果分析表明,本文结论也同样适用于磁心磁导率很高或线圈均匀密绕于磁心表面,即漏磁通很小可以忽略的情况。In order to study electrical and magnetic field distributions in toroidal core with circular cross section for high-frequency electronic circuits,when it is encircled partly by coil and leakage flux can not be ignored,according to magnetic flux continuity principle and mirror image method,electrical and magnetic field distributions in toroidal cores encircled by one coil are transformed into electrical and magnetic field distributions in the actual section of an infinite long cores along which an infinite number of images are introduced. Based on Maxwell equations and superposition principle,analytical solutions are derived for the electrical and magnetic field intensity,in which the field variables are expressed as a single series in terms of Bessel functions and trigonometric functions. Two analytical solutions of eddy-current power loss are derived. One is based on electric field intensity and the other is based on self impedance. Calculation results agree with each other,and it validates the accuracy and validity of analytical method. Calculation results of electrical and magnetic field intensity show that the conclusion of this paper can be applied to the case of magnetic permeability of core being very high or the core being encircled tightly and uniformly by coil,in which leakage flux can be ignored.

关 键 词：环形磁心 电磁场分布 解析解 贝塞尔函数 

分 类 号：TM554[电气工程—电器]