基于马尔可夫链的双随机PWM技术研究

Study of the Dual Randomized Modulation Based on Markov Chains

开关功率变换器中应用双随机调制技术能有效地减小传导EMI,改善系统电磁兼容性,但引起了变换器输出电压脉动增加,精度降低。本文构建了两个独立的马尔可夫(Markov)状态转移概率矩阵,并将其引入到双随机调制技术中,建立了基于Markov链的双随机调制DC/DC变换器系统仿真功能模块。由系统仿真提供的结果表明,双随机调制方式中引入马尔可夫链,在不影响连续功率频谱特性的前提下,能有效地改善变换器的输出电压精度。

Dual randomized modulation used in power converters can effectually reduce conduct EMI, while it increases output voltage fluctuations. This paper sets a dual randomized modulation simulation model for DC/DC converter using two independent Markov chains. Meanwhile, the power spectrum density (PSD) of input current for the converters is present. As a result, the dual randomized modulation scheme based on Markov chain can not only improve electromagnetic compatibility of power converters, but also reduce output voltage fluctuations.