步桥220kV变电站4号主变压器短路故障分析

针对 2011 年 6 月 3 日,因用户侧 35 kV 开关柜发生三相短路,导致石嘴山供电局220 kV步桥变电站4号主变压器差动保护和重瓦斯保护相继动作,主变压器三侧开关切除的故障,对绝缘油色谱、绕组直流电阻、电压比、频响法绕组变形及低压短路阻抗测试结果进行综合分析。结果表明:该变压器内部发生了严重的放电性故障,中、低压侧绕组均发生了变形和匝间短路,且低压绕组三相绕组出现了严重的断股。

Short circuit fault analysis on No.4 main transformer in Buqiao 220 kV substation

On June 3, 2011, three-phase short circuit happened on customers side 35 kV switch cabi?net, resulted in the faults that No.4 main transformer differential protection and heavy gas protectionsuccessively take action, in Buqiao 220 kV substation of Shizuishan Electric Power Supply Bureau. Thecomprehensive analysis based on test results of insulating oil chromatogram, winding direct current re?sistance, voltage ratio, winding distortion and low voltage short circuit reactance. The result shows thatthe interior of transformer occur serious discharge fault, middle and low voltage sides windings appeardistortion and interturn short circuit, low voltage three-phase winding appear serious broken strand.