摘要
目前,基于线路换相变流器(LCC)的HVDC系统依靠常规控制系统实现线路故障隔离,存在隔离过程中电流峰值大、过流持续时间长的不足。为此,提出一种基于状态空间法的故障隔离策略。首先,建立线路整流端、逆变端单极金属性故障的等值电路,利用状态空间法求解故障电流和换流器电流的时域表达式;其次,基于电流特征分析,利用非线性规划方法求解故障后每个时段的最佳触发角,以降低故障电流峰值和过流时间并得到故障隔离策略。最后,在PSCAD/EMTDC中进行了仿真验证,结果表明了所提方法的有效性和对维持系统安全稳定的积极作用。
At present,the line fault isolation is realized mainly by routine control systems in the line-commutated converter(LCC)-based HVDC system,which usually results in large current peak and lengthy overcurrent duration.To this end,a state-space analysis-based fault isolation strategy is proposed in this paper.First,equivalent circuits of solid poleto-ground faults at rectifier and inverter terminals are established,and time-domain expressions of the fault and converter currents are obtained using state-space analysis.Second,based on the analysis of current characteristics,the nonlinear programming method is used to solve the optimal trigger angle at each period after the fault,to minimize the amplitude and duration of the fault current and obtain the fault isolation strategy.The approach has been verified via PSCAD/EMTDC simulation.The results manifest the effectiveness of the proposed strategy,and positive significance for maintaining the security of power systems.
作者
袁博
王颖
邵华
张倩茅
秦梁栋
戴志辉
滕正伟
YUAN Bo;WANG Ying;SHAO Hua;ZHANG Qianmao;QIN Liangdong;DAI Zhihui;TENG Zhengwei(Economic and Technology Research Institute of State Grid Hebei Electric Power Company,Shijiazhuang 050021,Hebei,China;State Grid Hebei Electric Power Company,Shijiazhuang 050021,Hebei,China;North China Electric Power University,Baoding 071000,Hebei,China)
出处
《电网与清洁能源》
2020年第12期9-18,共10页
Power System and Clean Energy
基金
国家自然科学基金项目(51877084)
河北省自然科学基金项目(E2018502063)
国家电网有限公司科技项目(SGHEJY00GHJS1900023)。
关键词
高压直流
单极故障
状态空间
故障隔离策略
非线性规划
high voltage direct current
pole-to-ground fault
state space
fault isolation strategy
non-linear programming
