【作者】 南日山；

【导师】 李伟力；

【作者基本信息】 哈尔滨理工大学 ， 电机与电器， 2003， 硕士

【摘要】 本文以大型水轮发电机稳态电磁场和温度场为研究对象，研究电机稳态运行时电机内部的电磁关系和发热机理。大型水轮发电机的实际运行是一个非常复杂的物理过程，为了准确的描述这一物理过程，从包括电磁场、温度场在内的多场耦合的角度进行分析是必要的。基于涡流分布系数法对电机内定子各股线内损耗分布进行较为详细的研究。研究结果表明，采用涡流分布系数法和传统所采用平均法计算损耗进而得到的温度场真实分布基本相同，可在工程中采用更为简便的涡流平均法计算损耗和温度场。大型水轮发电机励磁绕组匝间绝缘很薄，在以往的场计算中常忽略了它的存在。但是转子匝间绝缘整个加起来的面积接近一根导体的面积，因此这样对计算结果的精度有一定的影响。同时，在大型水轮发电机温度场的计算和分析中，绝缘层常常被忽略，但在一个很薄的股线绝缘层上将会有一个显著的温度变化。这将直接影响电机的设计。本文根据电磁场理论，从耦合场的弱耦合角度首先计算了定子具有分数槽绕组的大型水轮发电机的电磁场，采用付立叶谐波分析的方法把气隙磁密分解为空间基波和一系列谐波，进而计算出气隙磁场波形特征系数。通过对气隙磁场的分析可以计算出转子表面损耗，进而计算出转子的温度场分布。在场的计算中，讨论了转子匝间绝缘对电磁场及温度场的影响。以龙羊峡320MW发电机为例进行了计算，将理论计算结果与实验结果进行了比较，验证了计算的准确性。更多还原

【Abstract】 In this paper, the electric and magnetic relationship and heat generating principle are researched taking the steady electromagnetic fields and temperature fields of the large salient generator as researched object. The practical operation of large salient synchronous generator is a very complex physical process. To describe this physical process exactly it is necessary to analyze from aspect of coupled fields including electromagnetic and temperature fields. Calculating the distribution of losses in stator strands based on the eddy current distribution coefficient method. It shows that results from this method and the traditional method are nearly same. So, the average method can be applied to calculate the temperature field. Because insulation layers in strands and turns are very thin, they are always be out of consideration when calculating electromagnetic fields. But the whole areas of stator strands insulation may exceed that of one piece of strand and it will have certain of effect on the calculation precision. The same effect occurs for the turn insulation.. Also the insulation layers are always ignored in the calculation and analyze of hydrogenerator. However even a thin insulation layer may have a significant temperature drop and this will have a direct effect on the machine design.According to the theory of electromagnetic fields, the large salient synchronous generator with fractional stator slot are calculated and analyzed by the Finite Element Method (FEM) in this paper. The Fourier analysis method is applied to decompose the air gap magnetic density into the basic spatial component and a series of harmonic components and wave shape eigen coefficient of air gap magnetic field are calculated. Through analyzing the air gap magnetic field, stray loss on the surface of rotor can be worked out and moreover temperature field distribution in rotor can be obtained. Longyang Gorge 320MW hydrogenerator is taken for example and the calculating results and the measured results are compared to confirm the accuracy of calculation.更多还原