电力系统广域继电保护研究综述

分析了传统继电保护在保障电网安稳运行时存在的问题,对基于广域信息的继电保护研究涉及的主要内容进行了综述,包括:在线自适应整定、潮流转移识别、基于故障元件识别的广域后备保护.在线整定的目的是根据系统运行方式的变化,调整保护定值至最佳状态.计及的运行方式变化包括:电力设备投退、发电机出力与负荷变化等.潮流转移识别旨在防止传统后备保护的不适当动作引发电网连锁跳闸事故,主要方法有:支路开断前后输电断面的有功潮流比较、相邻支路电流比较.广域后备保护利用电网多点量测信息确定故障元件的具体位置,从根本上克服了传统后备保护整定复杂、可靠性低的问题.主要研究包括:基于传统主保护理论的故障识别算法、广域信息的容错性算法.最后,提出了以基于故障元件识别的广域后备保护为基础,构建面向智能电网的广域继电保护系统,并对其发展方向进行了展望.

Overview of power system wide area protection

The existing problems of traditional protections are analyzed and the main contents involved in the study of protection based on wide-area information are reviewed, including: on-line adaptive setting, flow transfer identification and wide area backup protection based on fault component identification. The on-line setting is to adjust the protective settings to the optimal state according to the change of system operation modes, including the change of electric device on-off state and the change of generator output and loads. The flow transfer identification is to prevent the improper protective actions which may lead to cascading trips, including the comparison of transmission section active powers and adjacent branch currents before and after branch break. The wide area backup protection utilizes multiple node measurements to locate the fault component, which has easier protection setting and higher reliability than the traditional back-up protection, including the fault identification algorithm based on traditional main protection theory and the information error tolerance algorithm. A wide area protection system based on wide area back-up protection is presented for smart grid and its development trend is prospected.