气相干燥过程中变压器铁心生锈的机理及预防措施

The Mechanism and Its Preventive Measures of Iron Rust During Transformer Vapor Phase Drying Process

在电力变压器的生产过程中,特别是器身煤油气相干燥阶段,铁心生锈问题偶尔发生。铁心生锈会造成变压器铁心多点接地、绝缘电阻降低、损耗增大,严重时危及变压器的安全运行。通过分析变压器铁心生锈的电化学过程,提出了与之相关的4大因素,即:铁、氧气、水分、温度,说明了各因素的形成条件和对应的控制方法。通过电力变压器生产实践,对器身气相干燥工艺过程的温度控制、真空度控制进行了优化,有效地解决了铁心生锈问题。最后,提出了铁心生锈的预防措施,对变压器厂的工装设备更新维护、厂房温湿度调节控制、变压器生产节拍控制有一定的指导意义。

Core rust is occasionally found during the production of power transformers, especially during vapor phase drying process. Core rust can make transformer multiple earthing, reduce the transformer insulation resistance, increase transformer losses and even impact its safety operation. Through the analysis of electrochemistry process, four related factors, namely iron, oxygen, moisture and temperature, were proposed,the sources and controlling of the factors were also illustrated. Combined with production experience, and with the optimization of temperature value and vacuum level during vapor phase drying process, core rust issue was finally solved. In the end, the preventive methods were proposed, which could help the maintenance of transformer production equipment, the controlling of temperature and humidity, and the production planning.