CAJ | 학술논문

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±400kV青海一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。
수착직류수전특별시다단직류수전기술적발전급엄범응용，다개환류기병련련접적접선방안득도월래월다적연구화응용。의탁±400kV청해일서장직류련망공정채용전자잠태방진적방법연구료2환류기병련결구여단환류기결구상비，재각충고장공황하계통과전압수평，이급벌피뢰기、교류피뢰기、중성모선피뢰기、직류겁선화6맥동중점피뢰기전류、능량변화적규률。결과표명，재모사공황하，고장후과전압수평화피뢰기전류、능량균유변화。발생환류변벌측접지고장시，벌피뢰기능량증가2배이상，교류단상、삼상접지고장후，교류피뢰기능량증가60％，인차재절연배합설계시수요상응증가피뢰기병련수량。소득연구결론가위다환류기병련결구과전압여절연배합설계제공삼고。
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.