Abstract:DuetotheweaksupportcapacityofthepowergenerationequipmentatthetransmissionendoftheDCtransmissionsystemwithahighproportionofrenewableenergy,therenewableenergypowergenerationequipmentfacestheriskofover-voltageoffgridaftertheDCfaultoccurs.Inordertopreventtheoffgridaccidentofrenewableenergy,thispaperfirstestablishesthesimulationmodelofrenewableenergyDCtransmissionsystemandanalyzestheformationmechanismoftransientovervoltageatthegeneratorendofrenewableenergy.Secondly,accordingtothelawofreactivepowertransmission,thispaperanalyzestheinfluenceofconventionalunits,dimmers,electricaldistanceandotherfactorsonrenewableenergyoffgrid,andquantitativelyanalyzesthevoltageregulationsensitivityofconventionalunits.Onthisbasis,theoffgridsituationofrenewableenergyisquantitativelyanalyzedbyusingtheshort-circuitratioindexofrenewableenergy.Finally,accordingtotheanalysisresults,thispaperputsforwardsomestrategiestopreventrenewableenergyoffgridafterDCfault,suchasimprovingtheshort-circuitcapacityandimprovingthehigh-voltagecrossingcapacityofthefan,whichareverifiedbyaBPAsimulationexampleofaplannedDCtransmissionsystem.Keywords:DCtransmissionsystem;transientovervoltage;dimmer;conventionalunit;shortcircuitratio;suppressionstrategy摘要：含高比例新能源的直流外送系统由于送端发电设备支撑能力薄弱，在直流故障发生后新能源发电设备面临着过电压脱网风险。为了防止新能源脱网事故的发生，首先建立新能源直流外送系统仿真模型分析新能源机端暂态过电压形成机理，其次根据无功传输规律分析常规机组、调相机、电气距离等因素对新能源脱网的影响，定量分析常规机组的电压调节灵敏度，在此基础上利用新能源短路比指标对新能源脱网情况进行量化分析，最后根据分析结果提出了提高短路容量、提高风机高压穿越能力等预防直流故障后新能源脱网的策略，采用某规划的直流外送系统BPA仿真算例验证策略的有效性。关键词：直流外送系统；暂态过电压；调相机；常规机组；短路比；抑制策略0引言中国的新能源装机总量已位列世界第一，然而新能源发电装置多配置于西部、北部地区，这种集中发直流故障引发直流外送系统新能源脱网问题研究曹昊1*，严欢2，王雷3，宋云亭4，袁性忠2，田浩5...
