Research On Stator Ventilation Structure Optimization Of Asynchronous Traction Motor For High Speed Train

High speed train has the advantages of safety,efficiency and comfort.It has developed rapidly and has gradually become the main means of transportation of railway transportation.As the core power component of high speed train,asynchronous traction motor features simple structure and reliable operation,which is of critical importance to the safety of the train.However,the limited installation space of the train makes it difficult for the motor to dissipate heat,and causes the problems such as excessive temperature,local heat transfer imbalance and insulation aging,which seriously threaten the safe operation of the train.Therefore,it is necessary to accurately calculate the temperature field and optimize the ventilation structure for the asynchronous traction motor of high-speed train.On the basis of reviewing the calculation method of the motor temperature field and the cooling structure of the traction motor,this paper takes a 600 k W high-speed train asynchronous traction motor as the research object,based on the principles of heat transfer and computational fluid dynamics,the finite volume method is used to calculate the fluid and temperature distribution characteristics of the motor under different stator ventilation structures.The focus of this paper is how to reduce the temperature of motor components and balance the axial temperature difference,at the same time,genetic algorithm is used to optimize the ventilation structure of motor stator.Firstly,the three-dimensional fluid-structure coupling model of asynchronous traction motor is established,and the fluid and temperature distribution of the motor under the original ventilation structure are calculated through the steps of grid division,heat source assignment and boundary setting.In addition,the simulation results are verified by experimental data.Secondly,the influence of the diameter and number of ventilation holes of the asynchronous traction motor on the motor fluid and temperature is explored,and the ventilation structure facing the stator slot of the motor is proposed.After detailed analysis and comparison of velocity,flow,temperature and axial temperature difference of each component under different schemes,regular conclusions are formed,which lays a foundation for further optimization of stator ventilation structure.Then,based on the aforementioned research conclusions,variable-section stator ventilation structures are proposed.After a detailed comparative analysis of the fluid and temperature distribution under the non-linear variable cross-section and linear variable cross-section stator ventilation structures,the optimal scheme is selected to further study the influence of the stator ventilation aperture and radial position on fluid and temperature under the variable cross-section structure.By finding the optimal solution step by step,the stator ventilation structure which is beneficial to reduce the motor temperature and balance the axial temperature difference can be found.Finally,according to the above research on stator ventilation aperture,number and variable cross-section structure,based on the genetic algorithm optimization theory,the optimization of stator ventilation aperture,number and two-section section structure is carried out with the goal of reducing the maximum temperature of and balancing the axial temperature difference respectively.After finding the optimal solution,the heat dissipation effect of the optimized ventilation structure is further verified by simulation,and compared with the original ventilation structure.