The Research Of The Eddy Current Loss And Temperature Rise Of Power Transformer

Power transformer is one of the most important devices in the power grid and powertransmission, the calculation of leakage magnetic field and thermal problem is a key problem inpower transformer design and calculation.Partial overheat phenomenon of transformer causedby the winding loss, which is the main sources in the transformer loss, will reduce the service lifeof materials insulation in transformers.With the continuous enlargement of unit transformercapacity, the study of the winding eddy current and temperature field is very useful.The paper firstly give a brief introduction of the topic background, significance,theresearch and In the domestic and overseas,and discusses the causes and classification oftransformer leakage magnetic field. Then taking a25MVA/220kV transformer as an example,Two-dimensional (2D) and three-dimensional (3D) calculation models are established by thedrawing software AUTOCAD,leakage magnetic field of the transformer winding are calculatedby the finite element software ANSYS,and extract the leakage magnetic flux density along radialand axial dierction, and calculate the eddy current losses in windings through finite elementmethod,as the base of analyzing the temperature field.According to the theory of heat transferand fluid mechanics, the fluid-solid coupled field of winding and oil flow distribution aresimulated by the software of FLUENT. The results of simulation are compared with theengineering algorithm, confirmed the feasibility of this method. Finally, the paper analysis thefactors affecting the distribution of temperature field,and it is a certain reference value for thetemperature rise of the coil to improve.