含跟网型储能的新能源多馈入系统小扰动电压支撑强度分析  

Small-Disturbance Voltage Support Strength Analysis for Renewable Multi-Infeed System with Grid-Following Energy Storage

作　　者：郝艺 周瑀涵 刘晨曦 吴琛 王乐瑶 辛焕海[1] Hao Yi;Zhou Yuhan;Liu Chenxi;Wu Chen;Wang Leyao;Xin Huanhai(College of Electrical Engineering,Zhejiang University,Hangzhou,310027,China;Planning and Construction Research Center of Yunnan Power Grid Corporation,Kunming,650033,China)

机构地区：[1]浙江大学电气工程学院,杭州310027 [2]云南电网有限责任公司规划建设研究中心,昆明650033

出　　处：《电工技术学报》2024年第11期3569-3580,共12页Transactions of China Electrotechnical Society

基　　金：云南电网有限责任公司电力规划专题研究“提升云南新型电力系统稳定性的新能源与储能协调配置规划研究”资助项目。

摘　　要：储能正常工作时包含充电和放电两种运行模式,导致多储能变流器和多新能源变流器构成的多馈入系统工作点多变,加剧了系统小扰动同步稳定性分析的困难程度。为此,该文聚焦锁相环主导的小扰动同步稳定问题,首先,推导了兼顾储能充/放电运行模式的电网强度评估指标广义短路比,并提出了基于广义短路比及设备临界短路比的系统电压支撑强度分析方法,进而实现了系统小扰动同步稳定裕度的快速评估;然后,探究了跟网型储能变流器的充/放电运行模式对系统小扰动同步稳定裕度的影响规律,并根据矩阵联锁特征值定理论证了跟网型储能变流器工作在充电模式时,系统的小扰动同步稳定裕度高于放电模式;最后,基于仿真算例验证了所提系统小扰动同步稳定性分析方法的有效性。With the integration of large-scale renewable energy resources and energy storage into the power grid through power electronic converters,power electronic multi-infeed system is becoming a typical form of modern power system.In particular,the growing penetration of grid-following converters through phase-lock loop under weak grid strength has resulted in frequent oscillation instability risks.Therefore,it is increasingly important to accurately quantify the system voltage support strength(referred to as system strength)and evaluate the stability margin of the system.The relative difference between the short-circuit ratio and device critical short-circuit ratio is commonly used to quantify the system strength and the small-disturbance synchronous stability margin.However,there are two operating modes of charging and discharging when the energy storage system works normally,which leads to the change of the steady-state operating point of the power electronic multi-infeed system composed of multiple energy storage converter and multiple renewable energy converter,and further aggravates the difficulty of small-disturbance synchronous stability analysis.In order to solve the above problems,this paper proposes the generalized short-circuit ratio(gSCR)as the grid strength index of multi-infeed system with energy storage and then presents a fast evaluation method of system strength source-network collaboration based on this index.Firstly,the frequency-domain model and the closed-loop characteristic equation of multi-infeed system with energy storage are established based on linearization analysis.Secondly,it is theoretically proved that the multi-infeed system with energy storage can be equivalently decoupled into a set of single-infeed subsystems based on the modal decoupling theory.On this foundation,the definition of the gSCR is extended from conventional renewable energy multi-infeed system to multi-infeed system with energy storage considering the charging/discharging operation mode.The system voltage support streng

关 键 词：系统强度 广义短路比 储能变流器 运行模式 小扰动同步稳定 

分 类 号：TM712[电气工程—电力系统及自动化]