多馈入直流系统电压稳定中静态负荷影响的定量分析和评估方法  

Quantitative Analysis and Evaluation Method for the Impact of Static Loads on Voltage Stability in Multi-Infeed Direct Current Systems

作　　者：王奕鑫 唐宇 叶琳 周靖皓 柳昂 辛焕海[1] Wang Yixin;Tang Yu;Ye Lin;Zhou Jinghao;Liu Ang;Xin Huanhai(College of Electrical Engineering Zhejiang University,Hangzhou 310027 China;State Grid Zhejiang Electric Power Co.Ltd,Hangzhou 310000 China;Huzhou Power Supply Company State Grid Zhejiang Electric Power Co.Ltd,Huzhou 313000 China)

机构地区：[1]浙江大学电气工程学院,杭州310027 [2]国网浙江省电力有限公司,杭州310000 [3]国网浙江省电力有限公司湖州供电公司,湖州313000

出　　处：《电工技术学报》2024年第23期7379-7393,共15页Transactions of China Electrotechnical Society

基　　金：国家电网公司科技项目资助(5108-202218280A-2-437-XG)。

摘　　要：随着多回直流集中落点受端电网负荷中心,交流电网相对变弱,因此分析负荷对直流多馈入系统电压稳定的影响,对精确度量受端电网电压支撑能力至关重要。该文首先建立了直流、负荷、交流电网的准稳态模型,推导了单馈入系统短路比受负荷影响的定量关系式;其次,基于结构保持和模态摄动理论,将包含负荷的多馈入系统雅克比矩阵近似解耦,分析了负荷对广义短路比的作用机理;最后,给出了基于数据驱动的广义短路比实用计算方法和稳定裕度评估流程。研究表明,考虑负荷影响后,广义短路比实际值改变,而临界值不变。仿真算例验证了所提分析方法的合理性和有效性。With the continuous growth of load and the expanding scale of HVDC projects,the spatial resources of HVDCs are gradually being occupied.The situation where new HVDC receiving-end converter stations are established in proximity to load centers has become increasingly unavoidable.Therefore,to ensure the safe and stable operation of the multi-infeed system,the quantification of voltage stability margin in the AC/DC system must take into account the influence of the load.The difference between the generalized short-circuit ratio(gSCR)and the critical generalized short-circuit ratio(CgSCR)is used to quantify the voltage stability margin of the AC/DC system.However,the existing definition of the gSCR has not taken into account the influence of the load,limiting its applicability.When considering the impact of the load in actual systems,the definition and calculation of the gSCR need to be changed.To address this issue,this paper proposes a method for analyzing and calculating the gSCR that considers the impact of the load.The new gSCR is a modification based on the original gSCR,and the modification is determined by various factors such as the size and type of the load.Firstly,considering a single infeed system,the impact of load on the short-circuit ratio is studied based on the system Jacobi matrix.Analytical expressions for the new short-circuit ratio are derived too.Secondly,for multi-infeed systems,a load equivalent modeling method is proposed which can unify the internal loads of the system onto the HVDC converter bus to avoid the dimension disaster caused by excessive loads.On this basis,the Jacobi matrix for the multi-infeed system is established by clustering the load-related components.Then,based on the modal perturbation method,the multi-infeed system Jacobi matrix is approximately decoupled,and the generalized short-circuit ratio considering the load impact is defined.Moreover,for practical computation of the generalized short-circuit ratio,a data-driven method for calculating the admittance matrix of the m

关 键 词：电压稳定 广义短路比 负荷特性 多馈入系统 模态摄动 

分 类 号：TM712[电气工程—电力系统及自动化]