基于保护动作概率模型的距离保护误动识别

Misoperation Identification of Distance Protection Based on Protection Operation Probability Model

由于潮流转移过负荷、整定值不合理引起的后备保护误动跳闸可能引发大规模停电事故。针对目前研究计算和通信规模较大、没有考虑误动概率等不足,建立保护监测评估系统。首先,基于测量值和保护动作边界距离建立保护元件动作概率模型,根据传统保护系统的分布式结构构建保护运行监测评估系统架构,制定保护误动的识别流程,并简单介绍针对可能误动的保护采取的闭锁并修改保护动作特性等措施;然后分析非故障线路在某些情况下可能被误动保护切除的案例。结果表明,所提方法能够快速确定线路故障及保护动作情况,可以根据误动概率识别当前存在误动危险的保护,避免保护误动事故发生。

Misoperation of backup relays caused by flow transferring or improper settings would trigger large-scale blackouts. In allusion to deficiencies of current researches, such as the large amount of computation and communication, and without considering protection probabilities, a protection monitoring and evaluation system was established. First of all, an operation probability model of protection relays was proposed and the hierarchical protection monitoring and evaluation framework was thereafter established according to the distributed structure of traditional protection systems. The identification process of protection misoperation was proposed. Some measures for relays with misoperation risk including blocking these relays and changing protection operation characteristic are also briefly introduced. Cases with regard to non-fault transmission line removed by protection misoperation are analyzed. The results show that the proposed method could quickly confirm the fault line. It could be used to detect protective relays with misoperation risks based on operation probability to prevent protection malfunction accidents.