【作者】 井永腾；

【导师】 李岩；

【作者基本信息】 沈阳工业大学 ， 电机与电器， 2014， 博士

【摘要】 随着电力工业的不断发展，我国生产的超高压、特高压大型电力变压器的额定容量不断增加，变压器的损耗和温升问题已成为国际电工领域的研究热点问题之一。负载损耗是变压器的主要性能参数，其包含的各个损耗分量作为变压器温升研究中的热源，其大小及分布直接影响变压器的热点温升分析。由于变压器在运输过程中体积受到一定的限制，大型变压器单位损耗大且散热困难，负载损耗、冷却特性及绕组区域温升的准确计算和分析是其设计的关键问题。本文针对大容量变压器的负载损耗中的各个损耗分量的分解问题、油流冷却系统的固有特性及工作状态、绕组区域温升问题进行了深入的理论计算分析与实验研究。主要研究内容如下：（1）应用三维非线性时谐场分析法，对变压器漏磁场进行了计算，并且将部分计算结果与实测值进行对比。指定位置漏磁场计算结果与实验值相对误差在5%以内，满足工程要求，验证了计算方法的有效性。（2）建立了考虑材料各向异性及不同屏蔽结构形式的大容量变压器三维有限元时谐涡流场计算分析模型，分析了变压器金属结构件中损耗及分布，通过对十八台不同结构形式及各极限分接运行情况下的变压器产品进行实验及分析，对变压器的负载损耗计算和实验结果进行了对比分析，确定了负载损耗中各个损耗分量所占的比重，并将此计算方法应用于新产品的研发。（3）基于权重系数方法建立了变压器绕组杂散损耗计算数学模型，准确地计算出变压器绕组中的杂散损耗。针对不同导线结构进行了实验，并且对数值仿真得到负载损耗计算结果与实验结果进行了对比分析，确定了此方法中的权重系数，提高了绕组杂散损耗的计算精度，并应用此方法对新产品进行了验证分析。（4）根据流体力学、流体动力学及粘性流体力学理论，提出了FVM—FLIC耦合方法，分析了变压器冷却系统油流特性，确定冷却系统的工作状态。建立大容量变压器流体域的数值分析模型，对变压器整体冷却系统油流特性进行计算与分析。通过对冷却系统油流特性的分析，确定了冷却系统动力源—油泵的工作点，进而确定冷却系统的工作状态，并将此计算得到的数据结果应用于绕组区域温升的计算。（5）基于电磁场、流场及温度场的多场耦合及流—固耦合方法，建立了变压器绕组区域温升计算模型，分析了变压器绕组区域温升分布。首先，通过对变压器电磁场的分析，计算出绕组区域的损耗及分布，得到绕组区域温升计算的热源；其次，对变压器整体油流冷却系统进行计算与分析，确定冷却系统的工作点和工作状态，得到绕组区域温度场计算的边界条件；最后，通过对变压器绕组区域进行多场耦合及流—固耦合计算分析，得到绕组区域的温升及分布。通过对变压器绕组区域进行光纤测温实验，并将计算结果与实验结果进行对比分析，修正计算方法，同时也验证了温升计算方法的有效性和实用性。（6）采用本文计算方法，对一台特高压、大容量的变压器进行优化设计及分析计算。在对变压器负载损耗的分解计算、油流冷却系统的分析和绕组区域温升的计算分析基础上，提出了改善绕组区域损耗分布的方法，建立了一套高效、节能的变压器油流冷却系统，简化了冷却结构，改善了变压器绕组温升，设计的产品通过了实验考核。更多还原

【Abstract】 With the development of power industry, the rated capacity of EHV, UHV large powertransformer is increasing, the losses and temperature rise of transformer has become one ofthe hot issues studied in the field of international electricity. Load losses is one of the mainperformance parameters of the transformer, which includes the various loss components isthe heat source in research of the transformer temperature rise, its value and distributionaffects the hot-spot and temperature rise analysis of transformer directly. Due to thedimeasion restrictions during the transportation, the specific losses is higher and heatradiating is difficulty, the accurate calculation and analysis of load losses, cooling systemand winding temperature rise are the key issues in design.This article focuses on the calculation and analysis of the decomposition of variousloss components which include reducing problems load loss, the inherent characteristics ofoil flow cooling system and working state analysis, winding temperature rise are carriedout in-depth theoretical calculation and analysis and experimental research. The maincontents are as follows:(1)3D nonlinear time-harmonic field analysis method is taken to calculate themagnetic leakage flux of transformer, and some of the calculation results are comparedwith the measured values. The relative error of calculation results and test value ofmagnetic leakage flux in specified location is within5%. This meets the engineeringrequirements and the validity of the calculation method is varified.(2) Establish the3D finite element time-harmonic eddy current calculation andanalysis model to consider material anisotropy and different forms of shielding structurefor large power transformer; analyze the loss and loss distribution in transformer structureparts. Through the analysis of18units’ transformer in different structure forms anddifferent ultimate tapping position, the comparision between the load loss and test values iscarried out and the various loss components of load loss is determined. This calculationmethod is applied to new product development. (3) Based on the weight coefficient method the mathematical model of transformerwinding stray loss is established, the stray loss of transformer winding is calculatedaccurately. Experiments are performed for wire in different structure, the load lossnumerical simulation results are compared with the experimental results and analyzed, theweight coefficient of this methodis has been determined; increase the calculation accuracyof winding stray loss is increased. This calculation method has been adopted in evoluationof new products.(4) According to fluid mechanics, fluid dynamics and mechanics of viscous fluidsknowledge, the inherent characteristics of transformer oil flow cooling system is analyzedand the wording status of the oil flow cooling system is determined, FVM-FLIC couplingmethod is brought forward, the numerical analysis model of large power transformer influid domain is established in order to calculate and analyze the cooling system of alltransformer oil flow cooling system. Through the research of the oil flow cooling systeminherent characteristics the pump operating point of the cooling system power source isdetermined, thus the working state of transformer oil flow cooling system also. The dataobtained from the calculation results are applied to the calculation of the windingtemperature rise.(5) Based on multi-field coupling and fluid-solid coupling method of electromagneticfield, fluid field and temperature field, the winding temperature rise calculation model isestablished, the temperature rise distribution in winding is analyzed. Firs, through theresearch and analysis of electromagnetic field, the loss and loss distribution of winding iscalculated to obtain the heat source of winding; second, the calculation and analysis towhole transformer oil flow cooling system is done, the operating point and working state isdetermined to obtain the boundary conditions for calculating winding temperature field;finally, through of the multi-field coupling and fluid-solid coupling method calculation andanalysis of the transformer winding area, the temperature rise and distribution of windingregion is obtained. Through fiber optic temperature measurement test, the calculationresults and test values are compared to correct the calculating method, and theeffectiveness and practicability of this temperature calculation method are verified also inthe meantime.(6) The calculation method used in this paper has been applied to the optimizeddesign and analysis calculations for one UHV, large power transformer. Based on thedecomposition calculation of transformer load loss, analysis of oil flow cooling system and calculation of winding temperature rise, improving the winding area loss distributionapproach is put forward and an efficient, energy saving oil flow cooling system oftransformer is established, the cooling structure is simplized, the transformer windingtemperature rise is improved, and the designed product has been passed the test checking.更多还原