混沌映射抑制DC-DC变换器EMI水平的实验研究

探讨了混沌频率调制技术在开关变换器中抑制电磁干扰的实际效果。详细地分析了被调制信号的频谱与混沌系统产生的调制信号的不变密度函数之间的关系。设计了一个简单的、具有均匀分布密度的tent映射混沌电路，并以此电路产生的离散时间混沌信号作为频率调制信号，加入到工作在闭环连续导电模式的Buck变换器中，从而在开关变换器中实现了混沌频率调制，使开关频率随混沌信号随机变化。实验结果证明该技术不但具有有效降低开关谐波峰值和对输出电压影响不大的优点，而且实现电路简单，是解决开关变换器电磁兼容性问题的一种新的有效途径和具有应用前景的技术。

Experimental Study on the Suppressing Emi Level of DC-DC Converter with Chaotic Map

The paper presents the effectiveness of EMI suppression of switching converters with a chaotic frequency modulation scheme (CFMS). Arguments are given highlighting the link between the spectrum of the modulated signal and the invariant probability density function of the chaotic system generating the modulating signal. A tent-map chaotic circuit is designed and adopted as the modulating signal source. The discrete-time chaotic signal is incorporated into the Buck converter operating in the continuous-conducted mode, which makes the switching frequency randomly vary with the chaotic signal. The experimental results show that, by means of CFMS, the peak levels of the switching harmonics effectively decrease and the output voltage is slightly influenced, indicating that CFMS is applicable to switching converters..