随着列车运行速度的提高,弓网离线及离线电弧的发生率大幅上升,对牵引传动系统电气特性的影响日益显著,因此有必要研究弓网电弧对牵引传动系统电气特性的影响。为此,考虑了离线电弧的演化过程,建立了牵引传动系统仿真模型;研究了不同弓...随着列车运行速度的提高,弓网离线及离线电弧的发生率大幅上升,对牵引传动系统电气特性的影响日益显著,因此有必要研究弓网电弧对牵引传动系统电气特性的影响。为此,考虑了离线电弧的演化过程,建立了牵引传动系统仿真模型;研究了不同弓网离线时间下弓网离线对牵引传动系统电压特性的影响,并分析了离线过程中不同阶段的电压谐波情况。研究结果表明：弓网离线时间较长且在电弧熄灭的情况下,弓网离线对牵引传动系统电气特性的影响最严重;从电压方面来看,弓网离线时间为300 ms的工况下,熄弧后车载变压器高压侧出现的过电压值为47.5 k V,牵引变流器直流侧电压快速降为零,在离线恢复时产生的过电压值可达到6.4 k V,会对其中的电力电子器件产生严重冲击;从波形畸变程度来看,车载变压器高压侧电压的总谐波畸变率（total harmonic distortion,简称为THD,符号为λTHD）随着时间的延长而增大,畸变的电压输入牵引变流器,增加了其控制难度,恶化了变流质量。综上所述,弓网离线时间越长,弓网离线对牵引传动系统交直流侧电压的影响就越大,进而威胁到牵引传动系统电气设备的安全稳定运行。展开更多
Appropriate interaction between pantograph and catenary is imperative for smooth operation of electric trains.Changing heights of overhead lines to accommodate level crossings,overbridges,and tunnels pose significant ...Appropriate interaction between pantograph and catenary is imperative for smooth operation of electric trains.Changing heights of overhead lines to accommodate level crossings,overbridges,and tunnels pose significant challenges in maintaining consistent current collection performance as the pantograph aerodynamic profile,and thus aerodynamic load changes significantly with operational height.This research aims to analyse the global flow characteristics and aerodynamic forces acting on individual components of an HSX pantograph operating in different configurations and orientations,such that the results can be combined with multibody simulations to obtain accurate dynamic insight into contact forces.Specifically,computational fluid dynamics simulations are used to investigate the pantograph component loads in a representative setting,such as that of the recessed cavity on a Class 800 train.From an aerodynamic perspective,this study indicates that the total drag force acting on non-fixed components of the pantograph is larger for the knuckle-leading orientation rather than the knuckle-trailing,although the difference between the two is found to reduce with increasing pantograph extension.Combining the aerodynamic loads acting on individual components with multibody tools allows for realistic dynamic insight into the pantograph behaviour.The results obtained show how considering aerodynamic forces enhance the realism of the models,leading to behaviour of the pantograph-catenary contact forces closely matching that seen in experimental tests.展开更多
文摘随着列车运行速度的提高,弓网离线及离线电弧的发生率大幅上升,对牵引传动系统电气特性的影响日益显著,因此有必要研究弓网电弧对牵引传动系统电气特性的影响。为此,考虑了离线电弧的演化过程,建立了牵引传动系统仿真模型;研究了不同弓网离线时间下弓网离线对牵引传动系统电压特性的影响,并分析了离线过程中不同阶段的电压谐波情况。研究结果表明：弓网离线时间较长且在电弧熄灭的情况下,弓网离线对牵引传动系统电气特性的影响最严重;从电压方面来看,弓网离线时间为300 ms的工况下,熄弧后车载变压器高压侧出现的过电压值为47.5 k V,牵引变流器直流侧电压快速降为零,在离线恢复时产生的过电压值可达到6.4 k V,会对其中的电力电子器件产生严重冲击;从波形畸变程度来看,车载变压器高压侧电压的总谐波畸变率（total harmonic distortion,简称为THD,符号为λTHD）随着时间的延长而增大,畸变的电压输入牵引变流器,增加了其控制难度,恶化了变流质量。综上所述,弓网离线时间越长,弓网离线对牵引传动系统交直流侧电压的影响就越大,进而威胁到牵引传动系统电气设备的安全稳定运行。
基金support of RSSB to this work via the project RSSB/COF-UOH-49 is greatly appreciated.The authors also acknowledge the support by FCT,through IDMEC,under LAETA,project UIDB/50022/2020.
文摘Appropriate interaction between pantograph and catenary is imperative for smooth operation of electric trains.Changing heights of overhead lines to accommodate level crossings,overbridges,and tunnels pose significant challenges in maintaining consistent current collection performance as the pantograph aerodynamic profile,and thus aerodynamic load changes significantly with operational height.This research aims to analyse the global flow characteristics and aerodynamic forces acting on individual components of an HSX pantograph operating in different configurations and orientations,such that the results can be combined with multibody simulations to obtain accurate dynamic insight into contact forces.Specifically,computational fluid dynamics simulations are used to investigate the pantograph component loads in a representative setting,such as that of the recessed cavity on a Class 800 train.From an aerodynamic perspective,this study indicates that the total drag force acting on non-fixed components of the pantograph is larger for the knuckle-leading orientation rather than the knuckle-trailing,although the difference between the two is found to reduce with increasing pantograph extension.Combining the aerodynamic loads acting on individual components with multibody tools allows for realistic dynamic insight into the pantograph behaviour.The results obtained show how considering aerodynamic forces enhance the realism of the models,leading to behaviour of the pantograph-catenary contact forces closely matching that seen in experimental tests.
