准谐振开关变换器新的建模方法

摘要

According to the time-variant and nonlinear dynamic characteristics of QRC(Quasi Resonant Converter),its operating modes and operating principle are analyzed based on Boost ZVS-QRC. A modeling approach of QRC is presented,including its illative process and implementation steps. Its circuit is divided into low frequency section and high frequency section. The inductor and capacitor of low frequency circuit are represented respectively as ideal current source and ideal voltage source. Within a period,the steady-state of high frequency circuit is analyzed and the inductor voltage and capacitor current of low frequency circuit are averaged to get a unified system state equation. Simulative comparison among the Boost ZVS-QRC model,the QRC model based on the proposed modeling approach and the QRC model based on the state-space averaging Principle is carried out with Matlab,which shows that the simulative result of the QRC model based on the proposed modeling approach is closer to that of actual circuit model.%根据准谐振开关变换器时变的、非线性的动态特性,以Boost ZVS-QRC为例分析了其工作模态和工作原理,提出了一种针对准谐振开关变换器新的建模方法,给出了该方法的推理过程和建模步骤.该方法把准谐振电路分为低频电路和高频电路两部分,低频电路部分电感和电容分别用恒流源和恒压源表示,在一个周期内对高频电路部分进行稳态分析,对低频电路部分的电感电压、电容电流在一个周期内进行平均,得到了统一的系统状态方程.应用Matlab对Boost ZVS-QRC原电路模型、新的建模方法数学模型和状态空间平均法数学模型进行仿真对比,结果表明新的建模方法更接近于实际电路模型的仿真结果.