350MW发电机定子绕组直流泄漏电流不平衡查找及原因分析
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摘要
针对某电厂350MW发电机先后2次发生绕组直流泄漏电流不平衡问题,通过测试三相定子绕组绝缘电阻、吸收比以及定子绕组在不同直流耐压下的泄漏电流,发现2次都是由定子泄漏电流偏大引起的,机组于第2次检修时更换了12、30、31号槽下层绕组和11、28、34号层槽上层绕组,并重新对绕组端部进行加固处理。通过本次机组A级检修,彻底消除了该机三相定子绕组泄漏电流不平衡的缺陷,满足DL/T 596—1996《电力设备预防性试验规程》要求。
Aiming at the two problems of unbalanced DC leakage current of secondary winding of 350 MW generator in a power plant,the insulation resistance,absorption ratio and leakage current of the three-phase stator winding under different DC withstand voltages were tested,and it was found that the leakage current of the stator was both caused by overproof of large leakage current.During the second unit overhaul,the lower windings of slots 12,30 and 31 and the upper windings of slots 11,28 and 34 were replaced,and the ends of the windings were reinforced again.Through this A-level overhaul of the unit,the defect of unbalanced leakage current of the three-phase stator winding of the unit has been completely eliminated,and the requirements of DL/T 596—1996 Preventive Test Code for Power Equipment have been met.
Aiming at the two problems of unbalanced DC leakage current of secondary winding of 350 MW generator in a power plant,the insulation resistance,absorption ratio and leakage current of the three-phase stator winding under different DC withstand voltages were tested,and it was found that the leakage current of the stator was both caused by overproof of large leakage current.During the second unit overhaul,the lower windings of slots 12,30 and 31 and the upper windings of slots 11,28 and 34 were replaced,and the ends of the windings were reinforced again.Through this A-level overhaul of the unit,the defect of unbalanced leakage current of the three-phase stator winding of the unit has been completely eliminated,and the requirements of DL/T 596—1996 Preventive Test Code for Power Equipment have been met.
引文
[1]钟祖杰,张丽梅.发电机定子绕组泄漏电流不平衡率超标分析及处理[J].广西电力,2016,39(6):35-38.
[2]宁峻,曾雅琼.廖坊电厂发电机泄漏电流不平衡处理[J].江西电力,2011,35(2):41-42.
[3]崔孝强,杨宝梁,牟明.小山电站1号机组定子绕组泄漏电流不平衡原因分析[J].水电与抽水蓄能,2012,35(2):51-52.
[2]宁峻,曾雅琼.廖坊电厂发电机泄漏电流不平衡处理[J].江西电力,2011,35(2):41-42.
[3]崔孝强,杨宝梁,牟明.小山电站1号机组定子绕组泄漏电流不平衡原因分析[J].水电与抽水蓄能,2012,35(2):51-52.