【作者】 王福康；

【导师】 毛一之；

【作者基本信息】 河北工业大学 ， 电工理论与新技术， 2007， 硕士

【摘要】 随着城市电网用电负荷的逐渐增加,城网变电站深入城区和居民区越来越多,干式变压器便得到了广泛的应用,在不断的需求中,干式变压器本身也得到了巨大的发展。由于干式变压器具有诸多的优点。如:它适应高污秽、高温、潮湿的环境,具有阻燃、耐燃、无公害、免维护等一系列的优点。因此,越来越多地被应用于高层建筑及商业中心、石油、化工等对防火要求更高的部门。因此对干式变压器漏磁场和温度场的研究有很重要的意义。变压器的电磁设计与变压器的漏磁场密切相关。变压器的容量越大,漏磁场就越强,从而,由漏磁场引起的各种附加损耗也就增加,如设计不当它将造成变压器的局部过热,使变压器的热性能变坏,最终导致绝缘材料的热老化与击穿。在电力系统发生短路时,暂态短路电流产生的漏磁场还可能产生巨大的机械力,对其绝缘和机械结构造成致命的威胁。为了缓解漏磁场在上述两方面的影响,必须对变压器漏磁场进行全面的分析。本文运用电磁学基本理论,通过建立干式变压器的二维轴对称和纵切面模型,应用ANSOFT公司的MAXWELL软件,对干式变压器的二维漏磁场进行了分析,得出高压和低压绕组上的漏磁场分布情况,这为研究干式变压器的涡流损耗、温升、突发短路及有关电磁参数的计算奠定了基础。在得出总损耗的基础上,根据传热学和流体力学的原理建立了树脂浇注干式变压器内部温度场和流体场的有限元模型,利用ANSYS软件的流固耦合功能对其进行了热分析,得出高低压绕组内部径向和轴向的温度分布。经过上述的初步计算分析,为干式变压器的设计、研发提供了理论依据。更多还原

【Abstract】 With the city’s power grid increased, City Network Substation become more and more in the urban and residential areas. Dry-type transformers will be a wide range of applications. In constant demand, Dry-type transformer itself also obtained huge development. Because of dry-type transformer has many advantages, such as: it meet high filthy, hot and humid environment, having anti-burns, bears burns, maintenance and a series of advantages. Therefore more and more is applied to high-rise building and the business center, the petroleum and chemical industries where have higher requirements to fire safety and security. So analyse the leakage magnetic field and temperature field of dry-type transformer is important.The design of transformer electromagnetic and the leakage magnetic field are related closely. The larger transformer capability is ,the greater the leakage magnetic and the loss will be. If the transformer is not designed properly, the partial overheating caused by the loss in the transformer may destroy the thermal properties of the transformer and at last lead to aging and breakdown the insulation material. When the electrical power system occur short circuit, the leakage magnetic field caused by the short current may generate great mechanical power, making a great threat to the insulation and mechanical structure of the transformer. In order to alleviate the influences caused by the above two aspects ,it is very important to fully analyze the leakage of the dry-type transformer.According to the principle of electromagnetic field, with the Finite method, the two dimensional finite element models of Dry-type transformer are established. The fields are analyzed with the MAXWELL software of the ANSOFT company. From these analysis we got the leakage magnetic field in the high-voltage winding, Low-voltage winding and between them. This plays a fundamental role in research of temperature rising, eddy current loss, sudden-short-circuit and other electro-magnetic parameters in Dry type transformer.Based on the total losses in the transformer, according to the principle of the thermodynamics and hydrodynamics, the finite element models of temperature field and flow field of dry-type transformer are established. The fields are analyzed with the solid-flow coupling modules in ANSYS software.更多还原