多馈入交直流系统广义短路比的影响因素分析

Analysis of Influencing Factors of Generalized Short Circuit Ratio of Multi-infeed AC/DC System

多馈入交直流系统已经在我国南方电网和华东电网中普遍形成,多馈入广义短路比作为一种新型的指标能有效的评估多馈入交直流系统受端的强弱,是多馈入直流系统规划中的一种重要的参考指标,研究基于多馈入广义短路比的定义分析了直流落点间的联络阻抗、受端交流系统的等值自阻抗、直流功率等因素对多馈入广义短路比的影响及变化规律,所得的结论对于多馈入交流系统的规划及运行具有理论的指导意义,最后通过以在CIGRE标准测试系统的基础上扩展得到的两馈入系统为例,验证了理论推导所得结论的正确性。

The multi-infeed AC/DC system has been widely formed in China Southern Power Grid and East China Power Grid.Because of the strong complexity of multi-infeed AC/DC system,it is very difficult to evaluate the interaction between AC and DC systems.Generalized short circuit ratio as a new type of index can effectively evaluate the strength of multi-infeed AC/DC system,which is an important reference index in multi-infeed DC system planning.Based on the definition of generalized short circuit ratio,generalized short circuit ratio and its change rules influenced by the impedance of the contact group between the DC drop point and the equivalent self-impedance of the AC system and DC power are analyzed in this paper,the conclusions are of theoretical significance for the planning and operation of multi-infeed AC/DC systems.Finally,the results of the two-infeed AC/DC system verify the correctness of the theoretical conclusions.