输电线路行波测距式距离保护方法研究

主要针对行波测距式距离保护的难点即当对端母线有两回以上进出线时如何正确地区分正向区内区外故障。并且对于相间故障和接地故障提出了不同的方案。对于相间故障,首先给出了根据行波测距结果和行波波头计算故障过渡电阻方法,然后对区内区外故障测得的过渡电阻进行了分析,分析表明区内区外故障测得的过渡电阻有很大的不同,据此提出了一种区分区内区外故障的方法,而且此方法适用于三相故障。对于接地故障,提出了一种零模测距方法和线模测距方法相结合的保护方案,并且分析了接地保护对零模方法测距精度的要求。大量电磁暂态仿真证明了本保护原理的正确性。

Study on distance protection scheme based on traveling wave fault location

The schemes are presented for phase faults and earthing faults respectively. A calculated transient resistance method using results of fault location and initial traveling wave is proposed. The difference of transient resistances measured by protection is analyzed in the conditions of in-area faults and out-area faults. A scheme for distinguishing in-area faults from out-area faults is presented. It is applicable to three-phase faults, but is invalided for earthing faults. For earthing faults, a scheme combining zero-mode locating method and area-mode locating method is proposed. The simulation results validates the proposed schemes.