配电网距离保护的自适应跳闸方案

本文通过对输电线路的正方向区内、区外故障的分析，总结出区内故障的特点，并且利用这些特点，配合于距离保护Ⅱ段，实现加速跳闸。该方案克服了传统保护Ⅱ段的较长时限，在不采用通讯通道的情况下，保证保护的选择性，实现加速跳闸。本方案充分利用了微机的记忆功能和判别功能，保护记录下故障前的负荷电流，故障后的故障电流的存在及消失情况，利用逻辑判断回路，正确区分区内、区外故障，实现加速跳闸。

AN ADAPTIVE TRIPPING SCHEME COOPERATED WITH THE DISTANCE PROTECTION IN DISTRIBUTION SYSTEM

According to the difference between the positive fault in region and out of region, the paper proposes an adaptive tripping scheme cooperated with the distance relay, with the second relay tripping quickly. The scheme overcomes the second relay time limit of the conventional protection. The plan can make the relay trip quickly and does not lose its selectivity without the communication passage. The program takes full advantage of the microcomputer's memory storage function, recording the prefault load current, postfault current's existence and disappearance, making use of the logical circuit, distinguishing correctly the fault is in region or is out of region, making the relay trip quickly.