基于节点阻抗矩阵的直流配电网谐振特性分析

Analysis of Resonance Characteristics of DC Distribution Network Based on Node Impedance Matrix

为分析直流配电网谐振特性,在序分量动态相量谐波分析模型的基础上,分别建立直流配电网中并网换流器、交流负载接口换流器以及直流负载接口双向DC-DC换流器等关键元件的诺顿等值电路模型,进而构成直流配电网的等值电路模型。基于等值电路模型,形成直流配电网的节点阻抗矩阵。通过分析节点阻抗矩阵中各元素的频率特性,得到整个直流配电网的谐振特性,包括换流器自身及换流器间的谐波相互作用关系。接着深入研究影响直流配电网谐振特性的主要因素。通过仿真验证理论分析的正确性和有效性。

To analyze the resonance characteristics of DC distribution, firstly, a Norton equivalent circuit model of grid-connected converter, AC load interface converter and DC load interface bidirectional DC-DC were built based on the harmonic analysis model with dynamic phasor sequence components(DPSCs), respectively. Thus, the equivalent circuit model of DC distribution network was obtained. Secondly,based on the equivalent circuit model, the system node impedance was formed. Then, by analyzing the frequency characteristics of each element in the node impedance matrix,the resonance characteristics of the entire DC distribution network were obtained, including the harmonic interaction between different converter and the harmonic interaction of converter itself. Thirdly, the main factors affecting the resonance characteristics of DC distribution were deeply studied. Finally, the correctness and validity of the theoretical analysis were verified by simulation.