一起电流二次回路断线引起的变压器差动保护误动分析Analysis on Maloperation of Transformer Differential Protection Caused by Disconnection of Current Transformer Secondary Circuit
王祎,郑建梓
WANG Yi,ZHENG Jian zi
摘要(Abstract)：
TA二次回路断线对变压器比率制动特性的差动保护动作行为影响较大,110 kV变压器差动保护装置TA断线判别原理种类繁多,部分装置判据存在原理上的缺陷。对一起TA断线引起的差动保护误动原因进行分析,就不同保护装置的工作原理进行横向对比,提出要避免TA二次回路一相断线、且断线相和另一相电流并联这种特殊情况下比率差动误动,装置不应将存在零序电流作为TA断线判别的唯一或必要判据。
Disconnection of current transformer secondary circuit has great impact on differential protection action of ratio-restrained characteristic. There are a variety of disconnection discriminating principles for TA used in transformer differential protection device, and some criteria of the device have defects in principle. The paper analyzes the cause for maloperation of differential protection caused by TA disconnection and con- ducts lateral analysis on work principles of different protection devices. The paper also proposes to avoid mal- operation of ratio differential under circumstances of single-phase disconnection and parallel connection of the disconnection phase and another phase of current. The device should not take the existence of zero-sequence current as the unique or necessary criterion for TA disconnection.
关键词(KeyWords)：
变压器;差动保护;电流回路
transformer;differential protection;current circuit
基金项目(Foundation):
作者(Author):
王祎,郑建梓
WANG Yi,ZHENG Jian zi
DOI: 10.19585/j.zjdl.2013.11.013