Beat Frequency Oscillation Analysis for Power Electronic Converters in DC Nanogrid Based on Crossed Frequency Output Impedance Matrix Model
Beat Frequency Oscillation Analysis for Power Electronic Converters in DC Nanogrid Based on Crossed Frequency Output Impedance Matrix Model
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DOI：
10.1109/tpel.2017.2710101
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发表时间：
2018-04
影响因子：
6.7
通讯作者：
Xiaolong Yue;D. Boroyevich;F. Lee;Fang Chen;R. Burgos;F. Zhuo
中科院分区：
文献类型：
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作者：
Xiaolong Yue;D. Boroyevich;F. Lee;Fang Chen;R. Burgos;F. Zhuo
微电网中电力电子变流器的相互作用会导致系统不稳定和电能质量问题。现有的研究集中于低频区域的相互作用，如恒定功率负载，或极高频区域的相互作用，如电磁干扰。然而，功率转换器围绕其开关频率范围的相互作用并不包括在内。事实上，具有不同开关频率的DC-DC转换器之间的相互作用在某些情况下会引起拍频振荡。由于产生了额外的频率分量(拍频)，传统的阻抗概念不再是分析拍频振荡的工具，需要开发新的模型。本文提出了一种交频输出阻抗矩阵模型来描述DC-DC转换器在开关频率范围内的终端特性。在此基础上，建立了变流器的高频等效电路模型，用来预测不同开关频率的功率变流器相互作用产生的级联和并联系统中的拍频振荡。最后，提出了避免直流纳米栅中潜在拍频振荡的设计准则。对并联系统和串级系统的实验结果验证了所提出的预测方法和设计准则的准确性和有效性。
The interaction of power electronic converters in a microgrid can introduce system instability and power quality issues. Existing investigations focus on interactions either in low-frequency regions, such as the constant power load, or in very high-frequency regions like electromagnetic interference. However, interactions of power converters around their switching frequency range are not included. In fact, the interaction of dc–dc converters with different switching frequencies can introduce beat frequency oscillation in certain cases. Since additional frequency component (beat frequency) is generated, traditional impedance concept is no longer the tool for beat frequency oscillation analysis and new models need to be developed. In this paper, a crossed frequency output impedance matrix model is proposed to describe the terminal characteristics of a dc–dc converter around its switching frequency range. A high-frequency equivalent circuit model for the converter is then developed to predict the beat frequency oscillation in parallel and cascaded systems, which results from the interaction of power converters with different switching frequencies. Finally, design guidelines are proposed to avoid potential beat frequency oscillation in a dc nanogrid. Experimental results for both parallel and cascaded systems validate the accuracy and effectiveness of the proposed prediction method and design guidelines.