同步整流Buck变换器断续工作模式建模分析

作者运用能量守恒原理 ,考虑电感电流的纹波和开关器件的导通损耗 ,把非理想功率开关等效为理想开关与开通电阻的串联 ,理想开关由受控源替代 ,推导了同步整流Buck变换器在断续工作模式下的大信号平均模型、DC和小信号电路模型 ,导出了开环传递函数 ,进行了计算机仿真分析 ,结果令人满意。该建模分析方法的优点是考虑了电感电流的纹波和变换器的寄生电阻 ,模型直观、物理意义清晰 ,具有实用价值

Modeling Analysis of Synchronous Rectifier Buck Converter in Discontinuous Conduction Mode

This paper introduces modeling analysis of synchronous rectifier buck converter operating in discontinuous conduction mode (DCM). A new modeling method is given including inductor current ripples and parasitic resistors of the converter, based on the principle of energy conservation. Practical switch equals on resistance of the switch in series with an ideal switch replaced by dependent current and voltage sources. Large signal averaged, DC and small signal circuit models of synchronous rectifier buck converter operating in discontinuous conduction mode (DCM) are derived. The open loop transfer functions are derived. It satisfies the simulated models. Advantages of the proposed method are that the models include inductor current ripples and parasitic resistors of the converter. It is apparent and of clear physical significance, therefore, convenient for more analysis research.