According to the demands of the small commercial electric vehicle(EV)traction driving system,an 18kW inverter-driven induction motor(IM)with a die-casting copper squirrel cage rotor for traction drive was designed and...According to the demands of the small commercial electric vehicle(EV)traction driving system,an 18kW inverter-driven induction motor(IM)with a die-casting copper squirrel cage rotor for traction drive was designed and evaluated.The 2D finite element model of the designed IM was built by considering the nonlinearity of core materials,and the geometric parameters of the motor were optimized.The operational performance of torque versus speed characteristics and the efficiency over the speed range under the rated(continuous)and overload condition were investigated.Finally,the designed inverter-driven IM was developed and the performance of the IM operating in three typical modes were tested respectively.The experimental results of the designed motor operating in various driven mode were compared with that of 2D FEM.All the results proved that the designed inverter-driven IM could meet the target specification of the small commercial EV.展开更多
Copper alloy was adopted to prepare helicopter rotor counterbalance component by means of permanent-mold casting. Process parameters were determined on the basis of theory calculation and computer numerical simulation...Copper alloy was adopted to prepare helicopter rotor counterbalance component by means of permanent-mold casting. Process parameters were determined on the basis of theory calculation and computer numerical simulation. Through controlling mould temperature, pouring temperature and speed, the defects, such as gas cavity, shrinkage porosity, cold shut, can be effectively avoided. The results show that the best process parameters for smelting are as follows: pouring temperature is 1 100 ℃, pouring time is 14 s and opened mould time is 6 min. Mixture of 90% charcoal powder and 10% fluorite were selected as covering agent and 0.01% phosphorus copper acts as oxidizer. The density of rotor counterbalance component after casting in permanent-mold is 99.91% of its theory density. Mechanical properties are as follows: σb=315 MPa, σ0.2=143 MPa, δ=25%, HB=950. The mass deviation is between -5 g and +5 g, the curved surface distortion is less than 0.20 mm, and the largest tolerance of sectional thickness can be controlled between -0.10 mm and +0.10 mm.展开更多
以一台2极3 k W的三相异步电机为例,对比分析铸铝转子和铸铜转子对电机性能的影响。利用有限元法建立了电机的二维电磁场模型,对电机转子分别采用铸铜和铸铝时电机的起动性能、堵转特性、磁场分布、导条涡流分布、功率因数以及效率进行...以一台2极3 k W的三相异步电机为例,对比分析铸铝转子和铸铜转子对电机性能的影响。利用有限元法建立了电机的二维电磁场模型,对电机转子分别采用铸铜和铸铝时电机的起动性能、堵转特性、磁场分布、导条涡流分布、功率因数以及效率进行了对比分析,得出了转子材料对各个参数的影响规律,及当电机采用铸铜转子时所呈现的优缺点,为异步电机的优化设计提供参考。展开更多
文摘According to the demands of the small commercial electric vehicle(EV)traction driving system,an 18kW inverter-driven induction motor(IM)with a die-casting copper squirrel cage rotor for traction drive was designed and evaluated.The 2D finite element model of the designed IM was built by considering the nonlinearity of core materials,and the geometric parameters of the motor were optimized.The operational performance of torque versus speed characteristics and the efficiency over the speed range under the rated(continuous)and overload condition were investigated.Finally,the designed inverter-driven IM was developed and the performance of the IM operating in three typical modes were tested respectively.The experimental results of the designed motor operating in various driven mode were compared with that of 2D FEM.All the results proved that the designed inverter-driven IM could meet the target specification of the small commercial EV.
文摘Copper alloy was adopted to prepare helicopter rotor counterbalance component by means of permanent-mold casting. Process parameters were determined on the basis of theory calculation and computer numerical simulation. Through controlling mould temperature, pouring temperature and speed, the defects, such as gas cavity, shrinkage porosity, cold shut, can be effectively avoided. The results show that the best process parameters for smelting are as follows: pouring temperature is 1 100 ℃, pouring time is 14 s and opened mould time is 6 min. Mixture of 90% charcoal powder and 10% fluorite were selected as covering agent and 0.01% phosphorus copper acts as oxidizer. The density of rotor counterbalance component after casting in permanent-mold is 99.91% of its theory density. Mechanical properties are as follows: σb=315 MPa, σ0.2=143 MPa, δ=25%, HB=950. The mass deviation is between -5 g and +5 g, the curved surface distortion is less than 0.20 mm, and the largest tolerance of sectional thickness can be controlled between -0.10 mm and +0.10 mm.
文摘以一台2极3 k W的三相异步电机为例,对比分析铸铝转子和铸铜转子对电机性能的影响。利用有限元法建立了电机的二维电磁场模型,对电机转子分别采用铸铜和铸铝时电机的起动性能、堵转特性、磁场分布、导条涡流分布、功率因数以及效率进行了对比分析,得出了转子材料对各个参数的影响规律,及当电机采用铸铜转子时所呈现的优缺点,为异步电机的优化设计提供参考。
