Fine-grained Dynamics Representation and Stability Analysis for MMC-based Hybrid AC/DC Power Systems
Fine-grained Dynamics Representation and Stability Analysis for MMC-based Hybrid AC/DC Power Systems
复制标题
DOI：
--
复制
发表时间：
2022-09
期刊：
影响因子：
--
通讯作者：
J. Cao;C. Dong;Qian Xiao;Marui Li;Xiaodan Yu;H. Jia
中科院分区：
文献类型：
--
作者：
J. Cao;C. Dong;Qian Xiao;Marui Li;Xiaodan Yu;H. Jia
交直流混合动力系统以其巨大的能量传输能力和优良的可操纵性而备受青睐。然而，真实的系统规模庞大，内部动力学相互作用和耦合复杂，给系统运行带来了一系列的稳定性问题。为了研究交直流相互作用的动态特性，在状态空间中建立了基于MMC的混合电力系统模型。该模型考虑了AC和DC的详细动态及其相互作用，因此它可以用于AC/DC相互作用的研究，并提供比AC电力系统模型或MMC换流器模型更精确的稳定评估结果。通过MATLAB/Simulink仿真验证，该模型对MMC与传统电力系统之间的相互作用进行了深入研究，明确了MMC与传统电力系统之间的谐波耦合。还比较了不同系统的小信号稳定间隙。算例结果表明，该降阶模型可用于特定情况下的稳定性评估。这种相互作用导致交流中的额外谐波，影响混合系统的稳定性。
The hybrid AC/DC power system is favored because of its huge energy transmission capacity and excellent steerability. However, the real system is large in scale and the inner dynamics interaction and coupling are intricate, which introduces a series of stability issues for the system operation. To investigate AC/DC interaction dynamics, an MMC-based hybrid power system model is established in the state space. The model considers the detailed dynamics of both AC and DC, and their interaction, thus it can be used for AC/DC interaction study, and offer a more precise stability assessment result than either AC power system model or MMC converter model. After the verification in MATLAB/Simulink, The interaction is studied thoroughly by the proposed model, which clearly identifies the harmonic coupling between MMC and traditional power systems. The small signal stability gaps of different systems are also compared. Case results prove that the reduced-order model can be deployed to assess stability efficiently under specific circumstances. The interaction causes extra harmonics in AC affecting the hybrid system stability.