基于序电流相位比较和幅值比较的广域后备保护方法

Algorithm of Wide-Area Protection on Comparison of Current Phase and Amplitude

基于广域测量系统(WAMS)和同步数字体系(SDH)光纤环网的广泛应用,广域继电保护有助于解决传统后备保护整定配合复杂,潮流转移时引起级联跳闸等问题成为目前研究的热点之一。本文基于分区域分布集中式广域继电保护系统结构,提出一种新型广域后备保护方法,该方法结合系统故障时线路序电压和序电流的分布特点,实时监视分区域各母线序电压的启动,通过对启动母线序电压进行排序选出疑似故障线路,并利用疑似线路两侧的序电流相位和幅值比较构成广域后备保护故障线路识别判据:区外故障时,电流相位相同,大小相等;区外故障时,电流相位相反,大小不定。该方法只需上传故障疑似线路信息,减小了系统的通信量和计算量,同时采用分布参数线路模型消除线路分布电容的影响。该方法原理简洁,易于整定,且适用于系统高阻接地、非全相运行、转换性故障及潮流转移等复杂运行工况,IEEE 10机39节点系统仿真结果表明了算法的有效性和适应性。

Wide-area protection helping to the problems about the traditional backup protection’s setting complexity and cascading trip caused by flow transferring become a hot issue based on widespread use of wide-area measurement systemc(WAMS)and synchronons digital hierarchy(SDH).This paper proposes a novel fault identification algorithm of wide area protection based on centralized-distributed system architecture.The algorithm real-time monitors the starting signals among buses,and then compares bus sequence voltage to select a likely faulty line.Finally,the fault identification algorithm on comparison of phase and amplitude of current calculated by sequence voltage and current and line parameters is proposed,which current phase is coincidence and current amplitude is equal when external fault,in the contrast,current phase is invert and current amplitude is unequal when external fault.The algorithm decrease system communication traffic by selecting likely faulty line and realize the compensation of line capacitance current by comparing the calculation current.This algorithm could be set conveniently and could be immune to the complexity operating condition such as grounding resistance and open-phase running and cross-country fault etc.Simulation test based on IEEE 10-machine and 39-bus system illustrates the effectiveness and the adaptability of this method.