混沌频率调制降低开关电源传导EMI的研究  

Reduction of Conducted EMI in Switching Power Supplies with Chaotic Frequency Modulation

作　　者：李志忠[1] 李优新[2] 

机构地区：[1]华南理工大学,广东广州510640 [2]广东工业大学,广东广州510006

出　　处：《电力电子技术》2008年第7期71-72,45,共3页Power Electronics

基　　金：中国博士后科学基金(20070410236);广东省自然科学基金(06300282)~~

摘　　要：利用混沌频率调制技术从噪声产生源头上降低了开关电源传导电磁干扰。将蔡氏电路产生的混沌信号加入脉宽调制芯片,实现了混沌频率调制技术,使开关频率随混沌信号随机变化。简单分析了混沌频率调制降低EMI噪声的原理,并试制了一台混沌频率调制反激变换器电源样机。给出了开关管电流信号的频谱以及传导干扰测试的结果。实验结果表明,该技术能有效降低开关谐波峰值,使开关电源易于通过EMI测试,因此极具应用前景。Reduction of Conducted EMI in switching power supplies using chaotic frequency modulation scheme （CFMS） is proposed.Chaotic signal generated from Chua＇s circuit is incorporated into the pulse witdh modulator.Thus,the switching frequency varies randomly with the chaotic signal.The principle of suppressing EMI noise under CFMS is analyzed briefly and an experimental prototype of the flyback converter is constructed.The power spectral densities of the MOSFET＇s current and the conducted EMI test results are presented.The experimental results demonstrate that the CFMS can reduce the peak level of the switching harmonics effectively and make the power supply pass the EMI test easily.The CFMS has applied prospect in switching power supplies.

关 键 词：电源 脉宽调制/电磁干扰 混沌频率调制 

分 类 号：TN86[电子电信—信息与通信工程]