新一代计算机电源开关变换器的建模分析

Modeling Analysis of Switch Converter in the Future Computer Power Supply

介绍新一代计算机电源同步整流BUCK变换器工作在连续状态的建模分析 ,给出一种新的开关变换器的建模分析方法 .该方法考虑了变换器的寄生元件 ,功率开关等效为理想开关与开通电阻的串联 ,理想开关由受控电流源和受控电压源替代 ,基于能量守恒原理确定开通电阻等效平均值 ,为了简化模型 ,建立了将平均寄生元件转移到电感之路中的映射规则 ,推导了同步整流BUCK变换器工作在连续状态的大信号平均模型、线性电路模型、DC和小信号电路模型 ,导出了开环传递函数 ,并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变换器的寄生元件 ,其运算量比状态空间平均法小得多 ,模型直观、物理意义明确 ,便于进一步分析研究 .

This paper introduces modeling analysis of synchronous rectifier BUCK converter in the future computer power supply, which operates in continuous conduction mode (CCM). A new modeling method is given for including parasitic components of the converter. Power switch is equivalent to a series connection of an on resistance and an ideal switch with is replaced by dependent current and voltage sources. Equivalent average values of on resistance are determined based on the principle of energy conservation. In order to simplify the obtained models of the converter, a reflection rule is developed, with which averaged parasitic components are shifted to the inductor branch. Large signal averaged, DC and small signal circuit models of synchronous rectifier BUCK converter operating in continuous conduction mode are derived. The open loop transfer functions are educed. It satisfies the simulated models. The advantages of the proposed method are that the operation quantity of the method is much smaller compared with state space averaging method and the models include parasitic components of the converter. It is apparent and of clear physical significance, therefore, convenient for further analysis research.