基于LTspice的半桥LLC谐振变换器的参数设计与仿真

Parameter design and simulation of half-bridge LLC resonant converter based on LTspice

针对半桥LLC谐振变换器参数设计比较复杂且计算量大的问题,通过对半桥LLC谐振变换器的拓扑结构和开关过程的介绍,利用基波分析法建立谐振变换器的数学模型,得出了谐振变换器的直流增益;通过对半桥LLC谐振变换器原边开关管实现软开关的约束条件和其谐振参数对直流增益影响的分析,得到了谐振参数的设计过程.根据这种设计方法,在LTspice中搭建一个输入为400 V,输出为12 V,1.5 kW的仿真平台,验证了半桥LLC谐振变换器设计过程的可行性和有效性.

Aiming at the problem that the parameter design of the half-bridge LLC resonant converter contains massive computation and complex.Firstly,the topology and operating principle of the half-bridge LLC resonant converter are analyzed in this paper.Then the mathematical model of the half-bridge LLC resonant converter is established according to the fundamental harmonic approximation(FHA)to analyze the steady-state characteristics of the converter and the soft-switching constraints which achieve zero voltage switching by primary switching tube in detail.Therefore,another design process that has the characteristics of simple,small computation and simplified than that in the tradition of the half-bridge LLC resonant converter is given.Finally,a half-bridge LLC resonant converter with input voltage 400 V,output voltage 12 V,and 1.5 kW is designed based on this design method.In the meantime,the correctness and validity of the resonant parameter design are verified by LTspice simulation.