表征柔性直流电网电压动态特性的降阶小扰动稳定模型  

The Reduced-order Small-signal Model of VSC-DC Grid to Characterize the Dynamics of DC Voltage

作　　者：王一振 邱逢良 雷鸣[1] 王之谦 马世英 WANG Yizhen;QIU Fengliang;LEI Ming;WANG Zhiqian;MA Shiying(Key Laboratory of Smart Grid of Ministry of Education(Tianjin University),Nankai Distirct,Tianjin 300072,China;State Grid Hunan Electric Power Company Limited Research Institute,Changsha 410000,Hunan Province,China;China Electric Power Research Institute,Haidian District,Beijing 100192,China)

机构地区：[1]智能电网教育部重点实验室(天津大学),天津市南开区300072 [2]国网湖南省电力有限公司电力科学研究院,湖南省长沙市410000 [3]中国电力科学研究院有限公司,北京市海淀区100192

出　　处：《中国电机工程学报》2024年第19期7593-7602,I0009,共11页PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING

基　　金：国家自然科学基金项目(52377119,U22B20109)。

摘　　要：柔性直流技术是提高新能源渗透率,实现“双碳”目标的关键技术之一。低阶、准确的小扰动稳定模型有利于快速分析复杂柔性直流电网电压的超调振荡,为增强柔直系统安全稳定奠定基础。该文以表征直流电压动态特性为目标构建了直流电网降阶小扰动稳定模型。首先,建立直换流站直流侧阻抗模型的二阶解析式,把下垂外环控制参数等效为具有阻感特性的下垂导纳,并将不同控制模式下的柔直换流站以串并联阻抗电路形式统一表达;其次,基于直流网络拓扑聚合形成直流电网降阶传递函数阻抗矩阵,通过对降阶模型进行频率响应分析,定量探究多端柔直换流站通过直流网络耦合对直流电压动态特性产生的交互作用,指导下垂增益、外环控制系数等关键参数的选取;最后,在多场景电磁仿真中验证所述降阶模型的正确性与有效性。The voltage source converter(VSC)based DC technology is crucial for improving the rate of the penetration of renewable energy resources and achieving carbon peaking and carbon neutrality.Modeling with low order and moderate accuracy is of great significance for fast analysis of DC voltage dynamics and enhancement of system stability.Therefore,the reduced-order model of a VSC-DC grid is built to characterize the dynamics of DC voltage.First,the DC-side impedance of the VSC station is built in the form of second-order expression,which turns the droop-based outer control loop into a specified admittance with resistance-inductance characteristic.The VSC stations with different control are equivalent to a unified model of series-parallel impedance.Next,the reduced-order transfer function matrix of a VSC-DC system is formed based on the grid topology.The interactions of multi-VSC stations on DC voltage dynamics through DC grid coupling are investigated quantitatively by frequency response analysis,thereby guiding the parameters design of the droop gain and the outer control loop.Finally,the correctness and effectiveness of the proposed reduced-order model are validated by simulation.

关 键 词：柔性直流电网 降阶模型 下垂控制 直流电压控制时间尺度 小扰动稳定 

分 类 号：TM71[电气工程—电力系统及自动化]