谐振接地系统单相接地故障DK法选线及其应用

THE DK METHOD OF FAULT LINE DETECTION AND APPLICATION IN NEUTRAL RESONANT GROUNDED NETWORK

谐振接地系统单相接地后 ,采用DK选线法的控制装置延时投切消弧线圈的并联电阻 ,利用微机采样并计算出系统和线路系数 ,准确地判明故障线路 ,可与继电保护配合快速切除永久性接地故障。电网应用和现场测试表明 ,DK法克服了以往微机小电流接地选线装置和其它选线法选线准确率不高的问题 ,提高了城市中压配电网络的供电可靠性。

USING THE CONTROL DEVICE OF DK FAULT LINE DETECTION METHOD TO SWITCH THE SHUNT RESISTOR AND TO CALCULATE THE SYSTEM AND LINE COEFFICIENT BY MICRO COMPUTER SAMPLING, THE FAULT LINE CAN BE FOUND AFTER THE GROUNDING FAULT IN RESONANCE GROUNDING SYSTEM. THE PERMANENT FAULT CAN BE REMOVED COOPERATED WITH RELAY PROTECTION. THE APPLICATION IN SYSTEM AND FIELD TEST SHOWS THAT THE DK METHOD OVERCOMES THE WEAKNESS THAT THE DETECTION IS NOT ACCURATE BY OTHER FAULTY LINE DETECTION METHOD. THE RELIABILITY AND SAFETY IS IMPROVEMENT IN MEDIUM VOLTAGE POWER NETWORK.