计及交直流耦合作用的并网VSC小扰动稳定性分析  

Small-signal Stability Analysis of Grid-tied VSC Considering AC/DC Couplings

作　　者：朱克平 何英静 但扬清 李倩 曹建春 宗皓翔 ZHU Keping;HE Yingjing;DAN Yangqing;LI Qian;CAO Jianchun;ZONG Haoxiang(Economic and Technological Research Institute,State Grid Zhejiang Electric Power Co.,Ltd,Hangzhou 310008,China;China EPRI Science&Technology Co.,Ltd,Beijing 102200,China)

机构地区：[1]国网浙江省电力有限公司经济技术研究院,杭州310008 [2]中电普瑞电力工程有限公司,北京102200

出　　处：《电力系统及其自动化学报》2023年第6期106-115,共10页Proceedings of the CSU-EPSA

基　　金：国网浙江省电力有限公司科技项目(B311JY21000H)。

摘　　要：针对忽略交直流耦合动态而造成并网电压源换流器小扰动稳定分析失准的问题,本文具体分析了交直流耦合作用对其稳定性的影响。首先,建立了电压源换流器交直流阻抗模型,并给出扫频测量方法验证了其准确性;然后,构建了电压源换流器交直流并网系统的广义源荷模型,利用广义奈氏判据对其进行稳定性评估;最后,具体分析了传统交流阻抗与所提交直流阻抗的判稳区别,以及直流侧动态、无功功率传输对于系统稳定边界的影响。所得结果表明了计及交直流耦合特性对于电压源换流器并网稳定边界准确刻画的必要性。Aimed at the problem of inaccurate small-signal stability analysis due to the ignorance of AC/DC couplings,the effect of AC/DC couplings on the system stability is analyzed in detail in this paper.First,an AC/DC port imped⁃ance model of voltage source converter(VSC)is built,and its accuracy is validated by the frequency scanning measure⁃ment method.Second,the generalized source-load model for an AC/DC grid-tied VSC system is established,and its sta⁃bility is assessed by the generalized Nyquist criterion.Finally,three aspects are studied,including the difference be⁃tween the traditional AC impedance-based stability judgement and the proposed AC/DC impedance-based stability judgement,as well as the effects of DC-side dynamics and reactive power transmission on the system stability margin.Results indicate that it is necessary to consider AC/DC couplings for the accurate estimation of grid-tied VSC stability margin.

关 键 词：并网电压源换流器 交直流 阻抗 小扰动稳定性 奈氏判据 扫频 

分 类 号：TM712[电气工程—电力系统及自动化]