混沌映射抑制Buck变换器电磁干扰的研究

Research on Chaotic Map in Reducing EMI of Buck Power Converters

为了提高Buck变换器的电磁兼容性,基于混沌现象的宽频谱特性提出了一种新的变换器控制策略。首先推导了能够产生可控幅度混沌序列的Logistic映射形式,然后以峰值电流型滞环Buck开关变换器为研究对象,对其在混沌随机与常规周期两种工作模式下的时域和频域特性进行了对比分析,得出了混沌随机模式可以改善开关变换器的电磁兼容性的结论,但电感电流纹波却相应增加,从而降低了变换器的效率。仿真结果验证了该理论分析。

In order to improve the electromagnetic compatility of Buck converter, a new converter control strategy is presmted based on the wide band spectrum characteristic of chaos. Firtly a Logistic map which can produce chaos sequences of controllable amplitude is deducted, then takes a Buck switching converter with peak-current hysteresis as the study object, compares the time domain and frequency domain under the two operating modes between chaos random and normal period, lastly the conclusion that electromagnetic compatibility for the switching converter can be improved in the chaos random mode is achieved, however, the inductor current ripple increases and efficiency degrades accordingly. The theoy analysis is verfied by the simulation result.