Buck变换器的多频率矩阵模型及其在分布式供电系统中的应用

发布时间：2018-10-25 13:10

【摘要】：电力电子变换器是频域内典型的单输入多输出系统,当输入某一频率的扰动信号时,变换器各状态变量既包含扰动频率分量,也包含与扰动相关的边带频率成分。在包含多个电力电子变换器的分布式供电系统中,一个变换器的开关纹波为另一个变换器的扰动,这种相互作用在某些情况下可能会导致母线电压差频振荡从而影响系统电能质量。然而,传统小信号模型以单个变换器的分析和设计为背景提出,主要用于描述变换器的低频特性。由于这些模型忽略了开关变换器的很多固有特性,因此不能准确地分析上述变换器之间在开关频率附近的相互作用。为此,提出了一种新的矩阵小信号模型并以Buck变换器为例进行了详细的说明。该模型可以准确地描述变换器的单输入多输出特性,并解释分布式供电系统中电力电子变换器相互作用导致的母线电压差频振荡现象。对比结果表明,传统的平均小信号模型和多频率小信号模型都是所提出的矩阵模型在不同情况下的近似。仿真和实验结果证明了所提模型的准确性和有效性。
[Abstract]:Power electronic converter is a typical single-input multi-output system in frequency domain. When the disturbance signal of a certain frequency is input, each state variable of the converter contains both the disturbance frequency component and the side-band frequency component associated with the disturbance. In a distributed power supply system that includes multiple power electronic converters, the switching ripple of one converter is a disturbance of the other. In some cases, this interaction may lead to bus voltage differential frequency oscillation, thus affecting the power quality of the system. However, the traditional small-signal model is based on the analysis and design of a single converter, which is mainly used to describe the low frequency characteristics of the converter. Because these models ignore many inherent characteristics of switching converters, it is not possible to accurately analyze the interactions between the above mentioned converters near the switching frequency. Therefore, a new matrix small signal model is proposed and illustrated in detail with Buck converter as an example. The model can accurately describe the single input and multi-output characteristics of the converter and explain the bus voltage differential frequency oscillation caused by the power electronic converter interaction in the distributed power supply system. The comparison results show that the traditional average small signal model and the multi-frequency small signal model are approximate to the matrix model under different conditions. Simulation and experimental results show that the proposed model is accurate and effective.
【作者单位】：电力设备电气绝缘国家重点实验室(西安交通大学);
【基金】：国家高科技研究发展计划(863计划)(2015AA050606) 国家自然科学基金(51177130)资助项目
【分类号】：TM46

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