梳状电场屏蔽体高频电磁场屏蔽特性分析与应用  

Analysis & applications of comb-shaped electric shielding characteristics on high frequency electromagnetic fielding shielding effect in SMPS

作　　者：陈庆彬[1] 陈为[1] 

机构地区：[1]福州大学电气工程与自动化学院,福建福州350108

出　　处：《电工电能新技术》2013年第3期75-80,共6页Advanced Technology of Electrical Engineering and Energy

基　　金：国家自然科学基金(50877010);福建省自然科学基金(2009J01242)资助项目

摘　　要：开关电源中常用铜箔对磁性元件进行屏蔽以减小磁件与大地之间的电场耦合从而减小传导共模EMI发射。分析了传统全铜箔电场屏蔽体能有效屏蔽电场,但同时由于涡流效应也会影响高频磁场的分布,从而带来额外的涡流损耗和磁件电磁参数的变化,因此不适用于功率变换器中某些仅需要屏蔽电场但又不能屏蔽高频磁场的场合。提出的梳状电场屏蔽体结构具有只屏蔽电场,而不屏蔽高频磁场的特性,同时还能显著减低屏蔽体的临近效应涡流损耗。通过仿真分析了梳状屏蔽体结构参数对电场和高频磁场的影响。最后结合梳状屏蔽体在LLC集成漏感变压器中的应用验证了其实际有效性和可行性。Copper foil electric field shielding is commonly used in the SMPS to shield the magnetic components in order to reduce the electric coupling between the magnetic components and the ground. This paper analyzed in de- tail the traditional copper shielding foil, which can not only shield the electric field, but also affect the AC magnetic field distributions due to high-frequency eddy current effects and resulting in extra eddy current losses in the foil and the changes of magnetic parameters of the magnetic components. These behaviors are not suitable in many ca- ses, where only the electric field needs to be shielded. The comb-shaped electric shielding has good electric field shielding effect, but with no effect on the magnetic field. With the new shielding sheet ~ the eddy current effect due to AC magnetic field can be avoided. The influence of the structure parameters of the comb-shaped electric Shiel- ding to the electric field and high frequency magnetic field is analyzed by simulation. Finally, the application exam- ple of the electric shielding in LLC integrated transformer verified the proposed comb-shaped electric shielding to be effective and feasible.

关 键 词：开关电源 磁性元件 电磁干扰 电场屏蔽 涡流效应 

分 类 号：TM46[电气工程—电器]