电力电子主导的交直流混联电网振荡分析与评估  

Oscillation Analysis and Evaluation of the Power Electronics-dominated Hybrid AC/DC Grid

作　　者：宗皓翔 张琛[1] 蔡旭[1] ZONG Haoxiang;ZHANG Chen;CAI Xu(Key Laboratory of Control of Power Transmission and Conversion,Ministry of Education(School of Electronic Information and Electrical Engineering,Shanghai Jiao Tong University),Minhang District,Shanghai 200240,China)

机构地区：[1]电力传输与功率变换控制教育部重点实验室(上海交通大学电子信息与电气工程学院),上海市闵行区200240

出　　处：《中国电机工程学报》2023年第10期3844-3855,共12页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51837007)。

摘　　要：电力电子变流器主导的交直流混联电网极易产生各类振荡问题,为了对其进行有效的抑制和预防,需对系统进行全面的振荡分析与评估。对此,频域模态分析法(frequencydomain modal analysis,FMA)作为振荡诊断的有效工具,已成功应用于电力电子变流器主导的交流电网中。然而,FMA在对交直流混联电网振荡的评估中存在一定局限,即无法准确刻画广域/局域振荡特性。为此,该文结合FMA和对角占优理论,提出一种面向交直流混联电网的振荡分析与评估方法,能够准确反映广域/局域振荡特性,并获取振荡源、振荡传播以及振荡阻断等信息。首先,揭示交直流系统特有的局域振荡现象及其形成机理。其次,建立振荡评估指标体系,包括谐振模式指标、节点/支路/回路振荡指标和广域–局域振荡指标。最后,在MATLAB/Simulink平台上搭建一个风电场经多端柔直送出的测试系统,通过仿真分析验证上述振荡评估方法的有效性,所得振荡相关信息能够指导系统镇定方案的制定。The power electronics-dominated hybrid AC/DC grid has been suffering from various oscillation problems.To effectively suppress such oscillation issues,it is necessary to carry out a comprehensive analysis and evaluation of the system oscillation.In this respect,the frequency-domain modal analysis(FMA)method has been widely applied in the oscillation analysis of the power electronics-dominated AC grid.However,as will be revealed in this paper,there exist some limitations in the FMA when applied to the hybrid AC/DC grid,i.e.,inability to accurately characterize the wide-/local-area oscillations.Therefore,based on the FMA and diagonal dominance theory,this paper proposes an oscillation evaluation method for the hybrid AC/DC grid,by which the wide-/local-area oscillations can be well characterized and information like oscillation source,propagation and intercepting can be obtained.Firstly,the unique local-area oscillation phenomenon of the hybrid AC/DC grid is revealed as well as its formation mechanism.Secondly,the oscillation evaluation indices system is established,including oscillation mode index,node/branch/loop oscillation index and wide-/local-area oscillation index.At last,a multi-terminal HVDC transmission test system connected with large-scale wind farms is built in MATLAB/Simulink to validate the proposed evaluation method,where the oscillation relevant information obtained can guide the system stabilization plan-making.

关 键 词：交直流 振荡 模态分析 对角占优 广域/局域 

分 类 号：TM727[电气工程—电力系统及自动化]