Research On Heat Dissipation Performance Of Tubular Busbar Used In Wind Turbine

As a kind of clean energy,wind energy has the advantages of being renewable and rich in resource reserves.It has attracted more and more attention.Wind power generators are the main device that converts wind energy into electrical energy.With the maturity of wind power technology,large-capacity wind turbines will become the mainstream trend.As the unit capacity increases,the current of the current-carrying device also increases,which may cause problems such as heating and over-temperature of the current-carrying device.This paper takes the tubular bus in the wind turbine tower as the research object,and uses simulation software such as Maxwell and Fluent to carry out numerical simulations to calculate the flow field and temperature field of the air inside the tower under different environmental conditions and different power generation,as well as the temperature field of the tubular bus.Temperature distribution,compare the influence of the three-phase bus layout,layout spacing and other factors on the temperature field and flow field.The main research work and corresponding research results of this paper are as follows.Through numerical simulation,the current distribution in the three-phase busbars in the triangular arrangement and the vertical arrangement are obtained,and the influence of the busbar spacing on the current loss under the two arrangements is compared.The calculation results show that the busbars are more severely affected by the eddy current in the conventional triangular arrangement.The busbar spacing is increased to 560mm in the triangular arrangement to achieve uniform current distribution,and the busbar spacing reaches 280mm in the vertical arrangement,and the three-phase bus current is uniform.The current loss obtained by the solution is converted into a heat source and substituted into the numerical calculation model of the wind turbine tower.The flow field and temperature field of the air inside the wind turbine tower with a conventional triangular arrangement of the tubular busbars and the tube wall temperature of the tubular busbar are calculated.The calculation results found that when the ambient temperature increased from 20℃ to 40℃,the average wall temperature of the three-phase bus bar rose from 78℃ to 100℃.When the busbar current-carrying capacity is 2000A and the ambient temperature is 30℃,the wall temperature of some busbars exceeds the allowable standard 90℃.The wall temperature of the three-phase busbar increases by about 40℃ for every 1000A increase in the current carried by the three-phase busbar.For wind turbines with larger capacity,you should consider adding a cooling device or choosing a busbar with a larger cross-section to ensure that the busbar wall temperature is within the allowable range.On the basis of the above-mentioned numerical simulation,the flow field and temperature field inside the fan tower and the temperature of the tubular busbar are further calculated when the tubular busbar adopts vertical arrangement and circumferential arrangement.By comparing the temperature field and flow field near the busbar under the triangular arrangement,the vertical arrangement and the circumferential arrangement,it is found that the busbar wall temperature is the lowest in the circumferential arrangement.Increasing the busbar spacing will simultaneously affect the busbar loss value and the cooling performance of the surrounding air on the busbar.If the distance is too large,the cooling effect of the air on the bus bar will be weakened,which is not conducive to the heat dissipation of the bus bar.