基于非平均热源的换流变压器温度场仿真研究

发布时间：2018-05-14 07:13

本文选题：谐波磁场 + 非平均热源　；参考：《华北电力大学》2017年硕士论文

【摘要】：换流变压器在实际运行时绕组电流中含有大量高次谐波分量,会在绕组、铁心和金属结构件中产生谐波漏磁场和高次谐波损耗。由于损耗在绕组、铁心和金属结构件上的分布不均匀,局部区域过于集中的损耗会引起绕组、铁心和金属结构件的局部过热,使得换流变压器内部各区域温升差异明显,即出现换流变压器内部各区域温度分布不均匀的现象,而传统平均温升概念不能够准确且全面地反映出换流变压器的真实温度分布状况。因此准确地掌握热源(即损耗密度)的分布,将不均匀分布的损耗作为温度场的热源,可获得换流变压器内部准确的温度场和局部热点分布,为换流变压器绝缘设计和寿命预估提供依据。在国家青年自然科学基金项目“换流变压器谐波磁场、流体场-温度场和瞬态电场耦合问题研究”(51407075)和中央高校基本科研业务费专项资金资助项目“低温环境下变压器启动过程多场耦合问题研究”(2015MS79)的资助下,本文首先采用有限元方法对换流变压器铁心、绕组的谐波磁场及损耗分布进行分析;其次,研究异构网格节点数据映射算法,提出一种高精度、高效率的混合算法,将不均匀分布的磁场损耗准确传递到流体场-温度场相应网格单元中;最后,采用有限元方法对流体场和温度场进行计算与分析,对加载平均热源与非平均热源两种情况下的温度场分布进行了对比。
[Abstract]:A large number of high harmonic components are found in the winding current of converter transformers in actual operation, which will produce harmonic leakage magnetic field and high harmonic loss in windings, cores and metal structures. Due to the uneven distribution of losses on windings, iron cores and metal structures, the loss of local areas being too concentrated will cause local overheating of windings, iron cores and metal structures, which makes the temperature rise in different regions of converter transformers very different. That is the phenomenon of uneven temperature distribution in different regions of converter transformers and the traditional concept of mean temperature rise can not accurately and comprehensively reflect the true temperature distribution of converter transformers. Therefore, if the distribution of heat source (loss density) is accurately grasped and the loss of non-uniform distribution is taken as the heat source of temperature field, the accurate temperature field and local hot spot distribution in converter transformer can be obtained. It provides basis for insulation design and life prediction of converter transformer. In the National Youth Natural Science Foundation project "Converter transformer harmonic magnetic field," The study of fluid field-temperature field and transient electric field coupling problem "51407075" and "Research on Multi-field Coupling problem of Transformer Start-up process in low temperature" supported by the Special Fund for basic Scientific Research and Business expenses of Central University, China, China (2015MS79), Firstly, the harmonic magnetic field and loss distribution of converter transformer core and winding are analyzed by finite element method. Secondly, the data mapping algorithm of heterogeneous grid nodes is studied, and a hybrid algorithm with high precision and high efficiency is proposed. The magnetic field loss of non-uniform distribution is accurately transferred to the corresponding grid element of fluid field and temperature field. Finally, the finite element method is used to calculate and analyze the fluid field and temperature field. The distribution of temperature field under loading average heat source and non-average heat source is compared.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM42

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