Research On The Winding Temperature Field And Temperature Rise Testing Of 1000MVA/1000kV Power Transformer

Recently,the high-speed operation of the domestic economy makes the major industrial power consumption increased dramatically,how to meet the power consumption of industrial power,has become the focus of the next step in the national grid,thus accelerating the.growth of UHV power transmission technology.It is characterized by large capacity,transmission distance.UHV AC transformers are the necessary equipment for the technology to become a reality.In the field of power transformers,the technological content of the transformer is high and the manufacturing is difficult.Double million transformers because of its complex technology,large capacity,voltage level for the world's highest,so the problem is the loss of large,the study of its temperature rise at home and abroad to become one of the major concerns of electrical equipment industry.Load loss as one of the most important performance parameters of the transformer,composed of multiple loss components.These losses provide heat source,heat source size and distribution,will directly or indirectly affect the distribution of hotspot temperature rise.As the capacity of two million transformers,resulting in its larger size,in order to meet the size of the transport process restrictions,resulting in a large loss of transformer unit,resulting in internal cooling more difficult.Therefore,one of the technical problems faced by the transformer design is how to calculate and analyze the heat,cooling characteristics and winding temperature 'rise of the direct resistance of the winding.Therefore,it is very valuable to study and improve the distribution of the winding temperature and its hot spot in the oil flow velocity distribution of the windings under the different working conditions of the double million transformer.The temperature rise and the hot temperature rise after the reduction,can significantly improve the insulation life of the transformer.In the UHV substation,the current application is typical of two million(capacity of 1000000kVA,voltage of 1000000V)UHV power transformer,referred to as double million transformers.In this paper,the theoretical analysis of the distribution of each cake in each coil,the oil flow cooling structure and the working conditions of different coolers,the winding and the hot spot temperature rise are carried out for the load loss of the main transformer of the double million transformer,as well as the experimental studies.Firstly,based on the TranCalc integrated calculation software developed by SOFTTEAM Company,the temperature rise and the hot temperature rise of the transformer are calculated,and the causes of the hotspot temperature rise in each winding are analyzed,for the specific situation.Secondly,the oil flow structure of the transformer is studied,and the three-dimensional flow model is established.The contribution of different coolers to the oil flow inside the transformer is analyzed.The average velocity is calculated for the provision of boundary conditions of two-dimensional winding.Thirdly,through the establishment of two-dimensional winding model of double million transformers,using the theory of large commercial CFD(Computational Fluid Dynamics),heat transfer and so on,the flow velocity and temperature L is calculated.Finally,the principle of the two million transformer temperature rise test wiring and the test process were introduced.The temperature rise test data are processed by pushing the formula method and the extrapolation method,and the corresponding temperature gradient of the software is compared with the software.The difference is explained,which lays the foundation for the further research.