电力变压器绕组变形检测与诊断技术的现状与发展

Current Status and Development of Test and Diagnostic Technique of Transformer Winding Deformation

随着电网容量的日益增大,短路故障造成的变压器损坏事故呈上升趋势。及时有效采取检测手段对变压器绕组变形进行测试,能有效防止变压器已有变形的进一步恶化,最大限度地保证变压器不发生事故。从绕组变形的检测方法、检测原理、检测结果的影响因素和判断准则等几个方面进行归纳,综述了近年来变压器绕组变形领域的重要研究成果。同时,结合实际应用案例,从检测方式、测试结果的影响因素、检测信息量、检测灵敏度、变形判断方法及检测标准等角度对不同检测方法进行了分析比较。结果表明,扫频阻抗法能够较好地弥补低电压短路阻抗法和频率响应法在不同形式绕组变形灵敏度上的差异,提高绕组变形诊断的有效性;振动带电检测法无需停电就可开展变压器绕组变形检测。相比其它检测方法扫频阻抗法和振动带电检测法具有较明显优势,建议开展进一步现场应用研究,提高检测手段成熟度和变形判断方法的准确性。

With the increasing of the capacity in power system, transformer faults caused by short circuit are rising. Testing the transformer winding deformation timely by effective detection means can prevent further deterioration of the existing winding deformation, and ensure the transformer free of faults on the maximum limit. Therefore, we reviewed significant achievements in the research field in recent years, and summarized the detection method, the detection principle, the influential factors, and the judgment criteria of the winding deformation. Meanwhile, combining with practical application cases, we analyzed and compared the detecting methods, influential factors, detecting parameters, detecting sensitivity, deformation judgment criterion, and detecting standard. It is concluded that the sweep frequency impedance method compensates the sensitivity differences for low-voltage short-circuit impedance method and frequency response method on different forms of winding deformation, and improves the validity of the winding deformation diagnosis. Vibration detection method is able to detect transformer winding deformation without cutting off the power, Compared with the other two methods, this method has obvious advantages. It is suggested that this method be applied on practical testing to improve the maturity of detecting and judging methods.