多换流器并联运行的直流输电工程暂态过电压  

Transient Overvoltage of HVDC Power Transmission Project With Parallelly Operated Converters

作　　者：张赟 舒畅[2] 殷威扬 刘宝宏 聂定珍 

机构地区：[1]国网直流建设分公司,北京市宣武区100052 [2]华北电力大学电气与电子工程学院,北京市昌平区102206

出　　处：《电网技术》2012年第2期48-52,共5页Power System Technology

摘　　要：随着直流输电特别是多端直流输电技术的发展及广泛应用,多个换流器并联连接的接线方案得到越来越多的研究和应用。依托400 kV青海—西藏直流联网工程采用电磁暂态仿真的方法研究了2换流器并联结构与单换流器结构相比,在各种故障工况下系统过电压水平,以及阀避雷器、交流避雷器、中性母线避雷器、直流极线和6脉动中点避雷器电流、能量变化的规律。结果表明,在某些工况下,故障后过电压水平和避雷器电流、能量均有变化。发生换流变阀侧接地故障时,阀避雷器能量增加2倍以上,交流单相、三相接地故障后,交流避雷器能量增加60%,因此在绝缘配合设计时需要相应增加避雷器并联数量。所得研究结论可为多换流器并联结构过电压与绝缘配合设计提供参考。Along with the development and widespread application of HVDC power transmission technology, especially the multi-terminal HVDC power transmission, special attentions are paid to the research on the wiring scheme of parallelly connected multi-converters and such connection scheme is widely applied. Based on 4-400 kV DC power transmission project from Qinghai to Tibet in which the structure of two converters are parallelly connected, the apporach of electromagnetic transient simulation is adopted to research overvotlage level of this system under various fault conditions and the variation law of current and energy in valve arresters, AC arresters, neutral bus arrester, DC pole arresters and 6-pulse neutral bus arrester, and the simulation results are compared with those of single converter structure. Simulation results show that under some operating conditions the post-fault overvoltage level and current and energy in arresters vary. When gounding fault occurs at the valve side of converters, the energy in valve arrester will be increased to more than triple, and when single-phase or three-phase grounding fault occurs, the energy in AC arrester increases by 60%, therefore in the design of insulation coordination the number of parallelly connected arresters should be correspondingly increased. The obtained results are available for reference to the design of overvoltage and insulation coordination for HVDC power transmission projects adopting the structure of parallelly connected multi-converters.

关 键 词：直流输电 换流器并联接线 操作过电压 避雷器 

分 类 号：TM721.1[电气工程—电力系统及自动化] TM86