In order to make the on-line verification of relay protection setting more efficient and reasonable,the online checking sequence is determined by the comprehensive importance of relay protection.Most of the existing protection importance assessment methods fail to present a full view.To solve this problem,this paper takes the importance of network location of the protection and the severity of protection failure into account,and then,the evaluation model of protection comprehensive importance is constructed.Firstly,branch importance is presented by the active power betweenness of branch to quantify the importance of the branch which the protection located at.Then,based on protection fault chain model and risk theory,the severity of protection failure is,proposed to quantify the risk consequence of the chain of protection failure.Finally,coordination degree of protections is proposed to quantify the topological vulnerability of protection location.In order to compensate the limitation of the single weighting method,the weights of each index are obtained by combinational weighting method of relative entropy,and then,the comprehensive importance index of protection is obtained,and the on-line verification sequence of protection setting is conducted by the comprehensive importance index.Compared with the existing methods,this method evaluates protection importance more comprehensively,making the online checking sequence of protection setting more reference significance.In the end,the correctness and comprehensiveness of the proposed method are verified by a simulation example.

针对站域后备保护(SABP)信息同步性要求高和容错性低等问题,提出了一种基于改进证据理论融合的SABP算法。首先,SABP装置根据全站各线路两端传统主/后备保护和方向元件动作情况识别疑似故障线路,并由各疑似故障线路两端保护信息构成证据融合信息域。然后,搜集证据融合信息域内的主/后备保护和方向元件动作信息,经预处理后形成证据组并计算各证据的基本概率赋值,利用改进证据理论对证据信息进行融合判断来实现故障线路的识别。算例仿真表明,该SABP算法具有无需信息同步、站域信息交互的通信量小和信息容错性高等特点,能有效改善SABP性能。

目前对站域后备保护算法研究已有一定的进展,但对相应跳闸策略研究还比较缺乏。针对这一空白,本文提出了一种基于图论知识的站域后备保护跳闸策略。根据智能变电站拓扑结构、站间连接关系及断路器状态信息,形成实时站内元件-开关关联矩阵和站间元件-开关关联矩阵,然后结合故障元件和失灵断路器的具体情况建立站域元件-开关关联向量,并通过关联向量识别出站域后备保护在实现近后备保护功能和断路器失灵保护功能时所关联的断路器。算例分析表明,所提方法可适用于主接线形式复杂和运行方式变化的智能变电站,能实现自适应最小范围快速切除故障。