220kV变压器绝缘分析与改进

发布时间：2018-07-24 14:17

【摘要】：变压器是电力系统中最主要的电气设备之一,变压器的大多数故障都是由绝缘损坏引起的,可靠的绝缘结构设计不仅是变压器稳定运行的保障,同时也关系到电力系统的安全和电能的分配利用。变压器主纵绝缘设计是大型电力变压器,特别是超高压、特高压电力变压器的核心部分,它不仅对变压器运行安全可靠有决定性的意义,而且对变压器的经济指标也有极其重要的影响。本文主要对型号为SSZ11-180000/220的电力变压器的主纵绝缘分析。利用Ansoft有限元分析软件对主绝缘中部电场进行分析,确定了最大电场强度位置及绝缘裕度,找出绝缘薄弱点,并与传统解析法的计算结果进行了比较。本文计算了高压绕组波过程,得到了沿线圈的梯度分布,并分析相应的绝缘裕度。本文还探讨了冲击电压下的主绝缘计算分析,得出了电场分布。并与中部模型的最大电场强度进行比较,得出了冲击电压下的复合电场的最大电场强度比中部模型的最大场强更高。证明了对于电力变压器绝缘分析应当进行复合电场的校核,来保证绝缘设计的安全裕度。本文针对型号为SSZ11-180000/220电力变压器的纵绝缘裕度过大,提出了匝绝缘从1.95mm改进为0.95mm。通过对新绝缘结构进行计算与分析,验证了新绝缘结构中主绝缘及纵绝缘均有不足,分别采取了在首端1-8饼增加线饼角环、把高压绕组的屏蔽式从跨4屏改进为跨2屏,提高了新绝缘结构的可靠性。最后得出结论：新绝缘结构是可行的。
[Abstract]:Transformer is one of the most important electrical equipment in power system. Most of the faults of transformer are caused by insulation damage. Reliable insulation structure design is not only the guarantee of the stable operation of transformer, At the same time, it is also related to the security of power system and the distribution and utilization of electric energy. The main longitudinal insulation design of transformers is the core part of large power transformers, especially ultra-high voltage and ultra-high voltage power transformers. It is not only of decisive significance to the operation safety and reliability of transformers. Moreover, it has an extremely important influence on the economic index of transformer. This paper mainly analyzes the main longitudinal insulation of power transformer with SSZ11-180000/220. The electric field in the central part of the main insulation is analyzed by using the Ansoft finite element analysis software. The position of the maximum electric field strength and the insulation margin are determined, and the weak points of the insulation are found, and the calculated results are compared with those of the traditional analytical method. In this paper, the wave process of high voltage winding is calculated, the gradient distribution of the ring along the line is obtained, and the corresponding insulation margin is analyzed. The calculation and analysis of main insulation under impulse voltage are also discussed, and the electric field distribution is obtained. Compared with the maximum electric field intensity of the central model, the maximum electric field intensity of the composite electric field under impulse voltage is higher than that of the central model. It is proved that the composite electric field should be checked for insulation analysis of power transformer to ensure the safety margin of insulation design. Aiming at the large longitudinal insulation margin of SSZ11-180000/220 power transformer, this paper puts forward the improvement of turn insulation from 1.95mm to 0.95mm. Through the calculation and analysis of the new insulation structure, it is verified that the main insulation and the longitudinal insulation in the new insulation structure are deficient. The wire cake angle ring is added at the first end 1-8 cake, and the shielding mode of the high-voltage winding is improved from four screens to two screens. The reliability of the new insulation structure is improved. Finally, it is concluded that the new insulation structure is feasible.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM41

【相似文献】