【作者】 李邦云；

【导师】 丁晓群；

【作者基本信息】 河海大学 ， 电力系统及其自动化， 2004， 硕士

【摘要】 统计资料表明：在变压器各类故障中，绕组发生故障的机会最大，约占整个故障的60％-70％，在绕组各类故障中，最常见的就是绕组匝间短路(包括绕组层间短路、股间短路等等)，从广义上讲，绕组故障都可以归结于匝间短路。现代大型电力变压器普遍采用纠结式绕组，在改善绕组对冲击电压梯度分布特性的同时，也使得相邻线圈匝间电压升高，从而更容易导致匝间短路。绕组匝间短路后，尽管短路线匝里面流过数十倍的额定电流，但流出绕组外面的一次侧三相电流却很小，以至于传统的继电保护难以发现绕组轻微的匝间短路。绕组匝间短路后仍然能带满负荷继续运行，但是如果不采取相应的措施，故障将会进一步扩大，严重者至烧毁变压器，造成巨大的经济损失。 目前，国内外监测变压器的手段主要有：油中溶解气体在线监测、变压器局部放电在线监测、变压器绕组变形在线监测。最为成熟的方法是油中溶解气体在线监测，它能够有效的发现变压器早期潜在性故障，而后两者受到被监测特征量变化不明显以及现场干扰太大难以提取有效信号的制约在工程中应用非常有限。困扰变压器在线监测长期以来的问题之一就是：缺乏有效的监测特征量，特别是专门针对故障多发部件绕组尤其如此。 本文理论上分析了变压器绕组故障(匝间短路)后的各物理量的变化，从变压器功率损耗的机理入手，得出了结论：变压器绕组发生故障后，其功率损耗将有明显增大。找到了变压器在线监测特别是针对绕组在线监测的新特征量：功率损耗，并在电力局现场做了变压器绕组匝间短路试验。试验结果表明，该特征量对监测变压器绕组故障特别是匝间短路故障是行之有效的。在此基础上，探讨了实现变压器绕组在线监测的可能性，再结合油气量分析提出了相应的监测判断流程，并研制开发了一套电力变压器在线监测系统，将其应用于电力局工程实际。在论文的最后，初步探讨了变压器状态评估的框架。更多还原

【Abstract】 Statistic data indicate that windings is most possible blooey. Wingdings fault occupied 60%-70% in the power transformer. It is often that windings turn to turn short-circuit in all windings fault. Nowadays, it is be inclined to occur turn to turn short-circuit for transformer windings because of power transformer windings introduced tangle windings. Although inner short circuit current is very great, but external high voltage side current is not great after turn to turn short-circuit. So relay protection can’t detect fault. This is likely to burn transformer if don’t take any measures after turn to turn short-circuit.Within the country and abroad, the main means of on-line monitoring transformer is: dissolved gas analysis in oil partial discharge and windings deform on-line monitoring. In general, one problem of transformer on-line monitoring is: lack of monitoring characteristic, especially aimed at transformers windings.After analysis physical phenomena of turn to turn short-circuit, this thesis reached a conclusion: power losses must be increased when windings fault. So a new condition characteristic is put forward that used to be monitoring transformer windings, i.e. power losses. Power utility local test indicate that new characteristic is effective to monitoring transformer especially transformer windings. Based on possibility of on-line transformer monitoring, put forward a flow of on-line transformer combined oil characteristic. At last, empolder a system of transformer on-line monitoring and frame of transformer condition assessment is put forward.更多还原