龙羊峡水电站3号主变技术改造试验结果研究分析

Research and Analysis of the Test Results for 3~# Main TransformerMaintenance and Transformation on Longyangxia Hydropower Station

龙羊峡水电站3号变压器(以下简称3号主变)绝缘油色谱分析判断为高温裸金属过热故障后停运,现场吊罩检查确认故障为铁心拉板过热导致拉板对铁心绝缘丧失,造成铁心多点接地。该变压器为国内330 kV电压等级初期产品,原设计和制造工艺存在不足,造成铁心局部过热甚至碳化。对3号主变进行返厂技术改造,改造后再次投入生产并在大负荷下连续运行,升负荷试验中绝缘油色谱分析发现3号主变内部仍存在裸金属过热现象,文章针对此问题进行研究分析。

According to analysis the insulating oil chromatography of 3# main transformer,the shutdown is caused by bare metal high temperature heat,the failure of core drawing board overheating leading to the loss of insulation drawing board to core,and it caused core multi point grounding.The transformer is initial products of 330kV level,original design and manufacturing has deficiencies,and causing core local overheating and even carbon.After maintaining 3# main transformer,it still has bare metal overheating phenomenon,the paper makes analysis on this problem.