基于三状态马尔柯夫链的随机周期调制PWM技术研究

应用PWM调制技术的电力电子功率变换器中的全控型器件工作在很高的开关频率状态下，高速的开关动作会产生很高的dv/dt、di/dt，导致严重的电磁干扰。随机调制技术是一种直接控制干扰源，减小系统传导EMI、改善系统电磁兼容性的有效方法，但随机调制技术的应用会引起变换器输出电压纹波峰-峰值增加和精度降低。该文将一个优化了的三状态Markov链引入到随机周期调制技术中，通过对其原理的分析和对Boost变换器的系统仿真和实验分析，结果均表明，在随机调制技术中引入这种Markov链，同样可以降低系统产生的EMI，使功率频谱特性连续分布，在保证随机调制技术优点的同时，能够有效地降低功率变换器输出电压纹波峰-峰值，提高其电压输出精度。

Study of Randomized Period Modulation Based on Three-States Markov Chain

Full controlled components in power electronic converter using PWM work higher switch frequency. It can result in serious EMI because of higher dv/dt and di/dt produced by higher-speed switch action. Randomized modulation used in power converter can directly controls interference source and minishs conduct EMI and improves electromagnetism compatibility, while it increases output voltage fluctuate and reduces voltage precision. By result of simulation and experiment analysis of Boost converter, it can be concluded the randomized modulation based on three-states Markov chain can not only don't effect continues PSD，also reduce output voltage fluctuation peak-peak value and improve its precision.