Wheel polygonal wear can immensely worsen wheel/rail interactions and vibration performances of the train and track,and ultimately,lead to the shortening of service life of railway components.At present,wheel/rail med...Wheel polygonal wear can immensely worsen wheel/rail interactions and vibration performances of the train and track,and ultimately,lead to the shortening of service life of railway components.At present,wheel/rail medium-or high-frequency frictional interactions are perceived as an essential reason of the high-order polygonal wear of railway wheels,which are potentially resulted by the flexible deformations of the train/track system or other external excitations.In this work,the effect of wheel/rail flexibility on polygonal wear evolution of heavy-haul locomotive wheels is explored with aid of the long-term wheel polygonal wear evolution simulations,in which different flexible modeling of the heavy-haul wheel/rail coupled system is implemented.Further,the mitigation measures for the polygonal wear of heavy-haul locomotive wheels are discussed.The results point out that the evolution of polygonal wear of heavy-haul locomotive wheels can be veritably simulated with consideration of the flexible effect of both wheelset and rails.Execution of mixed-line operation of heavy-haul trains and application of multicut wheel re-profiling can effectively reduce the development of wheel polygonal wear.This research can provide a deep-going understanding of polygonal wear evolution mechanism of heavy-haul locomotive wheels and its mitigation measures.展开更多
Purpose–Auxiliary power system is an indispensable part of the train;the auxiliary systems of both electric locomotives and EMUs mainly are powered by one of the two ways,which are either from auxiliary windings of t...Purpose–Auxiliary power system is an indispensable part of the train;the auxiliary systems of both electric locomotives and EMUs mainly are powered by one of the two ways,which are either from auxiliary windings of traction transformers or from DC-link voltage of traction converters.Powered by DC-link voltage of traction converters,the auxiliary systems were maintained of uninterruptable power supply with energy from electric braking.Meanwhile,powered by traction transformers,the auxiliary systems were always out of power while passing the neutral section of power supply grid and control system is powered by battery at this time.Design/methodology/approach–Uninterrupted power supply of auxiliary power system powered by auxiliary winding of traction transformer was studied.Failure reasons why previous solutions cannot be realized are analyzed.An uninterruptable power supply scheme for the auxiliary systems powered by auxiliary windings of traction transformers is proposed in this paper.The validity of the proposed scheme is verified by simulation and experimental results and on-site operation of an upgraded HXD3C type locomotive.This scheme is attractive for upgrading practical locomotives with the auxiliary systems powered by auxiliary windings of traction transformers.Findings–This scheme regenerates braking power supplied to auxiliary windings of traction transformers while a locomotive runs in the neutral section of the power supply grid.Control objectives of uninterrupted power supply technology are proposed,which are no overvoltage,no overcurrent and uninterrupted power supply.Originality/value–The control strategies of the scheme ensure both overvoltage free and inrush current free when a locomotive enters or leaves the neutral section.Furthermore,this scheme is cost low by employing updated control strategy of software and add both the two current sensors and two connection wires of hardware.展开更多
基于中国铁路统计中心收集的年度统计数据，机车的 CO2 排出物在 1975-2005 期间被计算，当柴油机机车的与时间增加了时，排放紧张和它的动态特征是蒸气机车的 CO2 排出物减少了的 analyzed.The 结果表演，由于到柴油机和电的 locomotiv...基于中国铁路统计中心收集的年度统计数据，机车的 CO2 排出物在 1975-2005 期间被计算，当柴油机机车的与时间增加了时，排放紧张和它的动态特征是蒸气机车的 CO2 排出物减少了的 analyzed.The 结果表演，由于到柴油机和电的 locomotives.The 总数的从蒸气的连续移动，在中国的蒸气和柴油机机车的 CO2 排出物从 42.23展开更多
In the 16th and 17th century,Britain was constantly strained by sporadic plagues,famines,fires and political conflicts.As a response in literature,Shakespeare has constructed an annular locomotion paradigm in Fletcher...In the 16th and 17th century,Britain was constantly strained by sporadic plagues,famines,fires and political conflicts.As a response in literature,Shakespeare has constructed an annular locomotion paradigm in Fletcher and his collaboration work Cardenio.Be more specific,the locomotion routes can be exemplified in Möbius strip,a rhizome system,a reciprocating juxtaposition between the foreground and the background,either of which finally runs to an annular schema.The annular in narration corresponds with The Globe theater and the round world.Shakespeare may express his expectation and prospect for the uprising bourgeoise and the newly found world by the resurrection theme in literature.展开更多
Purpose–The brake controller is a key component of the locomotive brake system.It is essential to study its safety.Design/methodology/approach–This paper summarizes and analyzes typical faults of the brake controlle...Purpose–The brake controller is a key component of the locomotive brake system.It is essential to study its safety.Design/methodology/approach–This paper summarizes and analyzes typical faults of the brake controller,and proposes four categories of faults:position sensor faults,microswitch faults,mechanical faults and communication faults.Suggestions and methods for improving the safety of the brake controller are also presented.Findings–In this paper,a self-judgment and self-learning dynamic calibration method is proposed,which integrates the linear error of the sensor and the manufacturing and assembly errors of the brake controller to solve the output drift.This paper also proposes a logic for diagnosing and handling microswitch faults.Suggestions are proposed for other faults of brake controller.Originality/value–The methods proposed in this paper can greatly improve the usability of the brake controller and reduce the failure rate.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.U2268210,52302474,52072249).
文摘Wheel polygonal wear can immensely worsen wheel/rail interactions and vibration performances of the train and track,and ultimately,lead to the shortening of service life of railway components.At present,wheel/rail medium-or high-frequency frictional interactions are perceived as an essential reason of the high-order polygonal wear of railway wheels,which are potentially resulted by the flexible deformations of the train/track system or other external excitations.In this work,the effect of wheel/rail flexibility on polygonal wear evolution of heavy-haul locomotive wheels is explored with aid of the long-term wheel polygonal wear evolution simulations,in which different flexible modeling of the heavy-haul wheel/rail coupled system is implemented.Further,the mitigation measures for the polygonal wear of heavy-haul locomotive wheels are discussed.The results point out that the evolution of polygonal wear of heavy-haul locomotive wheels can be veritably simulated with consideration of the flexible effect of both wheelset and rails.Execution of mixed-line operation of heavy-haul trains and application of multicut wheel re-profiling can effectively reduce the development of wheel polygonal wear.This research can provide a deep-going understanding of polygonal wear evolution mechanism of heavy-haul locomotive wheels and its mitigation measures.
文摘Purpose–Auxiliary power system is an indispensable part of the train;the auxiliary systems of both electric locomotives and EMUs mainly are powered by one of the two ways,which are either from auxiliary windings of traction transformers or from DC-link voltage of traction converters.Powered by DC-link voltage of traction converters,the auxiliary systems were maintained of uninterruptable power supply with energy from electric braking.Meanwhile,powered by traction transformers,the auxiliary systems were always out of power while passing the neutral section of power supply grid and control system is powered by battery at this time.Design/methodology/approach–Uninterrupted power supply of auxiliary power system powered by auxiliary winding of traction transformer was studied.Failure reasons why previous solutions cannot be realized are analyzed.An uninterruptable power supply scheme for the auxiliary systems powered by auxiliary windings of traction transformers is proposed in this paper.The validity of the proposed scheme is verified by simulation and experimental results and on-site operation of an upgraded HXD3C type locomotive.This scheme is attractive for upgrading practical locomotives with the auxiliary systems powered by auxiliary windings of traction transformers.Findings–This scheme regenerates braking power supplied to auxiliary windings of traction transformers while a locomotive runs in the neutral section of the power supply grid.Control objectives of uninterrupted power supply technology are proposed,which are no overvoltage,no overcurrent and uninterrupted power supply.Originality/value–The control strategies of the scheme ensure both overvoltage free and inrush current free when a locomotive enters or leaves the neutral section.Furthermore,this scheme is cost low by employing updated control strategy of software and add both the two current sensors and two connection wires of hardware.
文摘基于中国铁路统计中心收集的年度统计数据，机车的 CO2 排出物在 1975-2005 期间被计算，当柴油机机车的与时间增加了时，排放紧张和它的动态特征是蒸气机车的 CO2 排出物减少了的 analyzed.The 结果表演，由于到柴油机和电的 locomotives.The 总数的从蒸气的连续移动，在中国的蒸气和柴油机机车的 CO2 排出物从 42.23
基金Chongqing Social Science Fund Project“The Ethical Topology of Shakespeare’s Histories”(2020WYZX07).
文摘In the 16th and 17th century,Britain was constantly strained by sporadic plagues,famines,fires and political conflicts.As a response in literature,Shakespeare has constructed an annular locomotion paradigm in Fletcher and his collaboration work Cardenio.Be more specific,the locomotion routes can be exemplified in Möbius strip,a rhizome system,a reciprocating juxtaposition between the foreground and the background,either of which finally runs to an annular schema.The annular in narration corresponds with The Globe theater and the round world.Shakespeare may express his expectation and prospect for the uprising bourgeoise and the newly found world by the resurrection theme in literature.
基金supported by the China Academy of Railway Sciences Foundation[Grant No.2021YJ244].
文摘Purpose–The brake controller is a key component of the locomotive brake system.It is essential to study its safety.Design/methodology/approach–This paper summarizes and analyzes typical faults of the brake controller,and proposes four categories of faults:position sensor faults,microswitch faults,mechanical faults and communication faults.Suggestions and methods for improving the safety of the brake controller are also presented.Findings–In this paper,a self-judgment and self-learning dynamic calibration method is proposed,which integrates the linear error of the sensor and the manufacturing and assembly errors of the brake controller to solve the output drift.This paper also proposes a logic for diagnosing and handling microswitch faults.Suggestions are proposed for other faults of brake controller.Originality/value–The methods proposed in this paper can greatly improve the usability of the brake controller and reduce the failure rate.
