一起电力变压器绕组变形综合分析

Comprehensive Analysis of Winding Deformation of a Power Transformer

绕组变形是电力变压器发生近区短路故障后损坏的主要原因,电力变压器绕组变形通常表现为绕组局部扭曲、鼓包或移位等。本文介绍了电力变压器绕组变形检测的常用方法及检测原理,结合一起110 kV电力变压器绕组变形试验数据异常实例,采用频率响应法、短路阻抗法及绕组电容量法进行了数据综合分析诊断,认为该电力变压器中压绕组及低压绕组存在变形的可能性大,最后对该电力变压器返厂开展吊罩解体检查,验证了分析结论的正确性。

Winding deformation is the main cause of power transformer damage following near-zone short-circuit faults.Winding deformation of power transformers is usually shown as the local twist,bulge or displacement of the winding.The common detection methods and principles of power transformer winding deformation are reviewed in this paper.Combined with a case of abnormal data in 110 kV power transformer winding deformation test,the frequency response method,the short-circuit impedance method and the winding capacitance method are used to comprehensively analyse the data and diagnose the fault.The results suggest that the mediumvoltage winding and the low-voltage winding of the power transformer are more likely to have deformed.Finally,the power transformer was returned to factory to carry out further inspection.which verified the aforementioned presumption.