串联谐振变换器的扩展描述函数法建模研究

摘要

Small-signal equivalent circuit of resonant converter is derived by extended describing function method.The curves of frequency domain are got through simulation.The influence of the major parameters such as input voltage, quality factor,duty ratio,and switching frequency are analy ed.Then,the experimental circuit was constructed and its frequncy-domain characteristics are measured,the experiment results are almost same with the simulation results, which demenstrated that extended describing function method for resonant converter is acurrate.%采用扩展描述函数法建立了串联谐振DC/DC变换器的小信号等效电路模型.通过仿真得到了频率特性曲线,分析了电路主要参数,包括输入电压、品质因数、占空比和开关频率对系统频率特性的影响.然后搭建了实际电路,利用频率特性分析仪测量了基于移相控制的串联谐振变换器的频率特性,实验结果与仿真结果具有良好的一致性,说明应用扩展描述函数法可较为准确地对谐振变换器建模.