探讨干式电抗器匝间短路故障与漏磁场的关系

摘要

Fault is frequently occurred in dry type reactor.It is shown by the fault analysis that all the burnt reactors have had inter-turn short circuit fault.It is known by the Maxwell equation that a reactor with inter-turn short circuit fault is equivalent to a dry-type air-core auto-transformer,with fewer turns and large transformation ratio at low voltage side.The current density in the short-circuit loop exceeds the normal designed value and the short-circuit loop can burn capacitor due to serious overheating,and thus cause a fire.In order to find out the inter-turn short circuit fault of the dry reactor in time,in this paper,the healthy condition of the reactor is analyzed through the variation of unbalance flux before and after the inter-turn short circuit of the reactor at the symmetrical center position of dry shunt reactor with three-phase pattern layout,and the verification result is inspected by way of simulating inter-turn short circuit test method, showing that the inter-turn short circuit fault of dry reactor with pattern layout and the leakage magnetic field variation of the symmetrical center position have an association relation.%干式电抗器经常发生事故,事故分析表明,所有烧毁的电抗器都发生过匝间短路故障,依据麦克斯韦方程可知,发生匝间短路故障的电抗器等效于一台干式空心自耦变压器,低压侧匝数很少,变比很大,短路环中电流密度远超过正常的设计值,短路环会严重过热而烧毁电抗器,引起火灾.为了及时发现干式电抗器的匝间短路故障,本文通过研究三相品字形布置的干式并联电抗器对称中心位置的不平衡磁通在电抗器发生匝间短路故障前后的变化分析该组电抗器的健康状态,并且通过模拟匝间短路试验的方法检验这一论证结果,说明品字形布置干式电抗器匝间短路故障与对称中心位置漏磁场变化量之间存在的关联关系.