Analysis And Calculation On Thermal Field Of Converter Transformer

As an important equipment in HVDC system, the converter transformer responsibility for power converting and dispatching in large power grid.With the investment and technology of DC power transmission in China increased support,and the capacity requirements of the converter transformer is also increasing,While the increase in capacity is also accompanied by a series of problems.And larger capacity will lead to greater eddy current loss, and the eddy current loss will generate heat, due to the complex structure of converter transformer, it easily occurs eddy loss concentration. And it will cause a series of problems such as transformer insulation aging, and therefore control the local overheating of the transformer has become an urgent problem to be solved. In order to better understand the distribution of temperature field of transformer partial loss and eddy current,the simulation and analysis to it is necessary.In this paper,the converter transformer to a model FAF-530405200 O as an example,at the first,establish the model of the winding with the application of ANSYS software, including the core, winding and oil, using the field-circuit coupled method based on electromagnetic and finite element theory,then simulate and calculate the leakage magnetic field in winding, and detailed analysis of it.After that,extract unit flux density on each wire,and get the numerical eddy current loss through calculation,then analysis it's trend.Secondly,established the three-dimensional models of transformer,after get the leakage magnetic field distributed in winding, after getting the feasible result on comparing with twodimensional winding model,we can get the result of the magnetic field distributed in structural numbers of the transformer after calculating, and obtaining the distribution of eddy current loss,then proposed the improvement measures to solve the concentrate of the eddy current loss according to the actual situation.Finally,distributed the two-dimensional model with winding, iron core and oil of the transformer by using FLUENT software, then solve and analysis it using theknowledge of the temperature field and the flow velocity field, getting the distribution of the whole temperature field and flow velocity field,then compared and simulated it with the same model distributed oil baffle,the results proved that these factors has certain influence on the distribution of temperature field.In this paper,based on the calculation and analysis of leakage magnetic field and eddy current loss of the winding and structural numbers of the transformer,getting the distribution of it, and simulate the phenomenon of using the flux shield,getting the result of the effect to decrease the loss of the structural numbers with flux shield.Increase the moderate number of oil baffle plate and compared the results,can get the effects on distribution of temperature conditions.