一种半桥式变换器设计及仿真分析

Design and Simulation Analysis of a Half Bridge Converter

为了研究半桥变换器中开关管驱动电路、功率变压器、输出滤波电感等参数对工作状态和技术指标的影响,基于电源仿真软件Saber建立了半桥变换器开环电路模型.给出了半桥变换器中功率变压器和输出滤波电感等关键参数的计算方法.采用分段线性分析法、小纹波近似分析法和伏-秒平衡条件对半桥变换器进行稳态分析,推导了输出滤波电感在连续导通模式下(CCM)和不连续导通模式下(DCM)输出、输入函数关系式.分析了半桥变换器CCM工作模式的输出电感、负载电阻和占空比的临界值计算方法.对所建的半桥变换器开环模型进行仿真,仿真结果验证了理论推导的正确性,据此给出了提高半桥变换器稳态性能和工作效率的参数设计方法,为半桥变换器设计提供了理论依据.

In order to study the influence of switching tube drive circuit,power transformer,output filter inductor and other parameters on the working state and technical indicators of half-bridge converter,an open-loop circuit model of half-bridge converter was established based on power simulation software Saber.The calculation method of key parameters such as power transformer and output filter inductor was given in half-bridge converter.The steady state of the half-bridge converter was analyzed by piecewise linear analysis,small ripple approximation analysis and volt-second equilibrium condition,and the output and input functions of the output filter inductor under continuous conduction mode(CCM)and discontinuous conduction mode(DCM)were derived.The critical values of output inductance,load resistance and duty cycle of CCM half-bridge converter were analyzed.The open-loop model of the half-bridge converter was simulated,and the simulation results verify the correctness of the theoretical derivation.Based on this,the parameter design method to improve the steady-state performance and working efficiency of the half-bridge converter was given,which provides a theoretical basis for the design of the half-bridge converter.