摘要
介绍了实现小接地电流系统单相接地故障自动选线的新方案──最大Ｉｓｉｎ或△（Ｉｓｉｎ）方案。此方案完全克服了零序电流自电流互感器二次侧中线取样时，由于ＣＴ不对称引起的不平衡电流Ｉｂｐ对电容电流的影响，且只有各出线电气量的相对比较，无需零序电流数值整定，对于有或无消弧线圈的系统，及有或无零序ＣＴ的现场，装置可根据外部写入的控制字选择最合适的判据。因此，装置灵敏度高，适应范围广。动模试验、型式试验及现场试验结果表明，装置正确选线率达１００％。
This paper introduces a new method named 'Maximizing Ising or △(Isin)'whieh is used to discriminate the faulted line or bus automatically when a single-phase short circuit to ground appears in the power system with floating neutral. The method completely overcomes the effect of unbalanced current Ibp on capacitor current caused by unsymmetrical CTs which are used for sampling zero-sequence current from neutral line on secondary sides of CTs. It is only necessary to compare the electrical quantities of all lines without zero sequence current setting values For the system with or without arc quenching coil in neutral and with or without zero scqucncc CT at site,thc device can select the best criteria according to the write-in control words. Therefore the device is of high sensitivity and wide application. The result from tested prototype on site has proved that the correct discriminating rate is approaching 100%.
出处
《中国电力》
CSCD
1995年第7期16-20,72,共6页
Electric Power
关键词
小接地电流系统
微机选线
试验
the system with floating neutral microcomputer-based faulty line discriminator unsymmetrical CTs
