MHz级平面变压器的设计及漏感与损耗的分析

Design of MHz Level Planar Transformer and Analysis of Leakage and Loss

基于反激变换器设计一款MHz级平面变压器。首先根据印制板平面变压器磁芯的最小结构常数初选了磁芯,利用磁芯损耗与温升的关系,初步选取了工作磁通密度,进一步计算了原副边匝数、线宽。在磁性元件设计软件Ansoft Pexprt中进一步完成平面变压器结构的设计,在有限元分析软件Maxwell 2D中对平面变压器的漏感与损耗进行了仿真。根据仿真设计,对变压器的印制电路板进行了布局,制作实物对漏感损耗进行了测试与计算,验证了平面变压器设计的正确性。

Planar transformer is an important factor to achieve high power density and high efficiency of switching power supply. In this paper, a MHz-level planar transformer is designed based on the flyback converter. Firstly, the magnetic core was selected according to the minimum structural constant of the pla- nar transformer core of the printed board. The relationship between the core loss and the temperature rise was used to select the working magnetic flux density, and the original secondary side turns and line width were further calculated. The planar transformer structure was further designed in the magnetic component design software Ansoft Pexprt. The leakage inductance and loss of the planar transformer were simulated in the finite element analysis software Maxwell 2D. According to the simulation design, the printed circuit board of the transformer was laid out, and the physical loss-to-leakage loss was tested and calculated to verify the correctness of the planar transformer design.