一起110 kV主变压器越级跳闸事故分析与处理

Analysis and Treatment of a 110 kV Main Transformer Overstep Trip Accident

介绍了一起110 kV主变压器越级跳闸事故,该事故因主变压器二次侧的中压线路开关CT烧毁,进而导致CT二次侧开路,相间短路电流保护失效,最终造成故障越级,由上一级的主变后备保护启动切除了故障。对故障后的试验结果和故障原因进行了分析,提出了预防CT开路造成事故的相关建议和措施。

A 110 kV main transformer overstep trip accident is introduced.The accident was caused by the burning of the medium voltage line switch CT on the secondary side of the main transformer,which led to an open circuit on the secondary side of the CT,and the failure of the short-circuit current protection between phases,and eventually caused the fault to leapfrog.The test results after the failure and the cause of the failure are analyzed,and relevant suggestions and measures to prevent accidents caused by CT open circuits are put forward.