摘要
大型风电能源基地通过特高压直流工程外送时,风机的接入使电网运行特性更加复杂多变,有必要研究单极接地故障下含风电场的特高压直流系统暂态特性。文中建立了风电接入的特高压直流系统电磁暂态仿真模型,通过等效模量法分析了单极接地故障下直流侧过电压的产生机理,讨论了交流侧及风机并网点电压波动的原因;在此基础上,研究了接地点位置、端部阻抗、功率输送等因素对系统电磁暂态特性的影响及规律。结果表明,双极运行下单极接地故障发生在线路中点时,健全极过电压最大;直流滤波主电容对健全极过电压影响较大;故障时无功功率不平衡导致风机接入点电压升高,该过电压与系统功率输送有关,可引起风机高压脱网并使故障继续扩大。文中获得了含风电特高压直流系统及风机的暂态特性及影响因素,对于指导过电压的抑制具有重要的参考价值。
When large-scale wind energy transmitted through ultrahigh voltage direct current(UH VDC)projects,its integration made the grid more complicated and versatile,and it is necessary to study the transient characteristics of wind power integrated UHVDC project under monopolar faults.In this paper,the electromagnetic transient simulation model has been built for wind power integrated UHVDC project.Equivalent modulus method is used to analyze the monopolar grounding fault under bipolar mode of the system,and the reason of voltage fluctuations on AC side and wind power connection point is discussed.Multiple factors have b een studied to evaluate their influence on the overvoltage,including fault location,terminal resistance,and transmission power etc.Results show that overvoltage on unfaulted pole reaches to maximum when the fault occur at the midpoint of the transmission line.The capacitance of DC filter shows quite influence on the overvoltage.The unbalanced reactive power during fault leads to voltage rise at the connection point of wind energy farm.This overvoltage relates to transmission power and may further cause wind turbine tripping and fault escalation.The transient characteristics and influencing factors of wind power integrated UHVDC and wind turbine are obtained in this paper,which has important reference value for guiding the suppression of overvoltage.
作者
杨楠
崔伟
王智伟
李武璟
牛拴保
刘财华
王泽宇
胡仁芝
惠思思
宋莹
YANG Nan;CUI Wei;WANG Zhiwei;LI Wujing;NIU Shuanbao;LIU Caihua;WANG Zeyu;HU Renzhi;HUI Sisi;SONG Ying(Northwest of State Grid Corporation of China,Xi’an 710048,China;Nari Group Corporation Co.,Ltd.,Nanjing 211000,China;Xi’an Jiaotong University,Xi’an 710049,China)
出处
《高压电器》
CAS
CSCD
北大核心
2020年第2期142-149,157,共9页
High Voltage Apparatus
关键词
特高压直流输电
风电接入
单极接地故障
风机
过电压
UHVDC
wind power integration
monopolar grounding fault
wind turbine
overvoltage
