CAJ | 학술논문

舟山多端柔性直流输电工程建成后将成为世界上第一个基于模块化多电平换流器(Modular Multilevel Converter, MMC)的五端柔性直流输电工程。为研究各换流站的过电压水平，依托舟山多端柔性直流输电示范工程，详细分析了换流站交直流侧的过电压机理，建立了基于详细控制保护策略的五端柔性直流输电系统过电压仿真模型，计算了换流站联结变压器阀侧单相接地、桥臂电抗器阀侧单相接地、直流极线接地、直流平波电抗器阀侧直流母线接地和直流极间短路等故障在换流站关键设备上产生的过电压。结果表明：联结变压器阀侧交流母线上的最大过电压为360 kV；直流极线上的最大过电压为370 kV，直流平波电抗器阀侧直流母线的最大过电压为369 kV，避雷器CB和D承受的最大能量分别为1.258 MJ和1.655 MJ；星形电抗接地支路中性点上的最大过电压为188 kV；桥臂电抗器两端产生的最大过电压为235 kV。计算结果可为该工程换流站的绝缘配合研究以及相关设备的选型、试验等提供重要依据。
주산다단유성직류수전공정건성후장성위세계상제일개기우모괴화다전평환류기(Modular Multilevel Converter, MMC)적오단유성직류수전공정。위연구각환류참적과전압수평，의탁주산다단유성직류수전시범공정，상세분석료환류참교직류측적과전압궤리，건립료기우상세공제보호책략적오단유성직류수전계통과전압방진모형，계산료환류참련결변압기벌측단상접지、교비전항기벌측단상접지、직류겁선접지、직류평파전항기벌측직류모선접지화직류겁간단로등고장재환류참관건설비상산생적과전압。결과표명：련결변압기벌측교류모선상적최대과전압위360 kV；직류겁선상적최대과전압위370 kV，직류평파전항기벌측직류모선적최대과전압위369 kV，피뢰기CB화D승수적최대능량분별위1.258 MJ화1.655 MJ；성형전항접지지로중성점상적최대과전압위188 kV；교비전항기량단산생적최대과전압위235 kV。계산결과가위해공정환류참적절연배합연구이급상관설비적선형、시험등제공중요의거。
Zhoushan multi-terminal VSC-HVDC project will be the first DC transmission project with five converter stations in the world which is based on modular multilevel converter (MMC) technology. To study the overvoltage of each converter station, overvoltage mechanism of AC and DC switchyard are analyzed in detail based on this project, and overvoltage levels in typical faults such as single-phase-to-ground fault at the valve side of converter transformer and at the valve side of converter reactor, DC pole line ground fault, ground fault at the valve side of DC smoothing reactor and DC to DC pole line fault are calculated based on the MMC-HVDC model with five stations. Results show that the maximum overvoltage for AC bus at the valve side of converter transformer is 360 kV;the maximum overvoltage for DC bus at the line side and at the valve side of the DC smoothing reactor are 370 kV and 369 kV respectively; the maximum overvoltage of the neutral point of star reactance grounded branch and converter reactor are 188 kV and 235 kV respectively;the maximum energy of arrester CB and D are 1.258 MJ and 1.655 MJ respectively. The research results will provide important basis for the insulation coordination of station devices.