一种开关变换器统一能量守恒平均模型

Uniform energy conservation average models of switching converters

针对不同开关变换器模型与拓扑结构密切相关,转换困难的问题,依据能量守恒平均原理,建立连续模式下隔离和非隔离buck、boost、buck-boost变换器统一直流和小信号模型,并给出开环传递函数。将变换器中寄生参数及储能电感折算到与输出电容串联的支路中,在考虑寄生参数影响的同时,减小变换器结构上的差异。所建立的模型可以通过拓扑因数的选择,方便的实现不同变换器模型的转换,有利于各种变换器的比较研究。该模型同样适用于含有同步整流结构的情况。仿真分析表明,模型能够准确描述变换器的频域特性,验证了理论推导的有效性。

To cope with the problem of conversion between topology dependent models of different converters, a uniform dc and small-signal models for both isolated and non-isolated buck, boost and buckboost converters and its open-loop transfer functions in continuous conduction mode （CCM） are established based on the energy conservation averaging principle. By transferring the parasitic parameters and inductor equivalently into the branch in series connection with output capacitor, the models are unified and the parasitic parameters are contained. The conversion between different models can be easily realized by simply changing the topology factors. It can be beneficial when comparing different conveners. Models and expressions can be also applied for synchronous rectifier mode. The proposed model is validated by detailed simulation and is shown to accurately predict small-signal frequency domain characteristics.