开关电源PCB的近场EMC预测优化设计

Near-field EMC Predictive Optimization Design of Switching Power Supply PCB

开关电源是典型的非线性负载,因具有功耗小、效率高、尺寸小、重量轻等特点被应用在舰船低压配电系统中。开关电源工作在高频时产生较强的电磁干扰(EMI)和高次谐波,这些噪声干扰不仅干扰自身的正常工作,也会污染周边的电磁环境。此处针对开关电源印制电路板(PCB)设计中引起的电磁兼容(EMC)问题,提出基于电磁场仿真的预测优化方法,通过建立PCB近场辐射等效模型,分析板图中辐射强度较大的区域,优化PCB布局走线,提高PCB设计的EMC特性。仿真结果表明,在设计阶段引入电磁场仿真的方法,可以预测PCB近场辐射特性,优化设计后能大幅度将低电磁场辐射强度。最后搭建了电源实验平台,通过实验验证了所提PCB EMC预测优化方法的有效性和可行性。

Switching mode power supply is a typical nonlinear load,it is used in the warship low power distribution system because of the characteristics of small power consumption,high efficiency,small size,light volume and so on.However,when switching power supply works at high frequency,it produces serious electromagnetic interference(EMI)and higher harmonics,which not only interfere with their own normal work,but also pollute the surrounding electromagnetic environment.Aim at the electromagnetic compatibility(EMC)problems caused by the switching mode power supply in the printed circuit board(PCB)design,near field radiation equivalent model of PCB is established based on electromagnetic filed theory,and the layout of the PCB is modified to improve the EMC characteristics of PCB design by analyzing the near field radiation distribution with stronger radiation intensity.Experiments show that the electromagnetic field simulation can be used to predict the near field radiation characteristics of PCB,and the electromagnetic radiation intensity can be greatly reduced after optimization.Finally,the experimental platform of switching mode power supply is built,the effectiveness and the feasibility of the proposed PCB EMC prediction optimization method is verified by experiments.