The main contribution of this paper is the development and demonstration of a novel methodology that can be followed to develop a simulation twin of a railway track switch system to test the functionality in a digital...The main contribution of this paper is the development and demonstration of a novel methodology that can be followed to develop a simulation twin of a railway track switch system to test the functionality in a digital environment.This is important because,globally,railway track switches are used to allow trains to change routes;they are a key part of all railway networks.However,because track switches are single points of failure and safety-critical,their inability to operate correctly can cause significant delays and concomitant costs.In order to better understand the dynamic behaviour of switches during operation,this paper has developed a full simulation twin of a complete track switch system.The approach fuses finite element for the rail bending and motion,with physics-based models of the electromechanical actuator system and the control system.Hence,it provides researchers and engineers the opportunity to explore and understand the design space around the dynamic operation of new switches and switch machines before they are built.This is useful for looking at the modification or monitoring of existing switches,and it becomes even more important when new switch concepts are being considered and evaluated.The simulation is capable of running in real time or faster meaning designs can be iterated and checked interactively.The paper describes the modelling approach,demonstrates the methodology by developing the system model for a novel“REPOINT”switch system,and evaluates the system level performance against the dynamic performance requirements for the switch.In the context of that case study,it is found that the proposed new actuation system as designed can meet(and exceed)the system performance requirements,and that the fault tolerance built into the actuation ensures continued operation after a single actuator failure.展开更多
A near-term strategy to reduce emissions from rail vehicles,as a path to full electrification for maximal decarbonisation,is to partially electrify a route,with the remainder of the route requiring an additional self-...A near-term strategy to reduce emissions from rail vehicles,as a path to full electrification for maximal decarbonisation,is to partially electrify a route,with the remainder of the route requiring an additional self-powered traction option.These rail vehicles are usually powered by a diesel engine when not operating on electrified track and are referred to as bi-mode vehicles.This paper analyses the benefits of discontinuous electrification compared to continuous electrification using the CO_(2)estimates from a validated high-fidelity bi-mode(diesel-electric)rail vehicle model.This analysis shows that 50%discontinuous electrification provides a maximum of 54%reduction in operational CO_(2)emissions when compared to the same length of continuously electrified track.The highest emissions savings occurred when leaving train stations where vehicles must accelerate quickly to line speed.These results were used to develop a linear regression model for fast estimation of CO_(2)emissions from diesel running and electrification benefits.This model was able to estimate the CO_(2)emissions from a route to within 10%of that given by the high-fidelity model.Finally,additional considerations such as cost and the embodied CO_(2)in electrification infrastructure were analysed to provide a comparison between continuous and discontinuous electrification.Discontinuous electrification can cost up to 56%less per reduction in lifetime emissions than continuous electrification and can save up to 2.3 times more lifetime CO_(2)per distance electrified.展开更多
基金This research was supported by the European Union’s‘Shift2Rail’through No.826255 for the project IN2TRACK2:Research into enhanced track and switch and crossing system 2
文摘The main contribution of this paper is the development and demonstration of a novel methodology that can be followed to develop a simulation twin of a railway track switch system to test the functionality in a digital environment.This is important because,globally,railway track switches are used to allow trains to change routes;they are a key part of all railway networks.However,because track switches are single points of failure and safety-critical,their inability to operate correctly can cause significant delays and concomitant costs.In order to better understand the dynamic behaviour of switches during operation,this paper has developed a full simulation twin of a complete track switch system.The approach fuses finite element for the rail bending and motion,with physics-based models of the electromechanical actuator system and the control system.Hence,it provides researchers and engineers the opportunity to explore and understand the design space around the dynamic operation of new switches and switch machines before they are built.This is useful for looking at the modification or monitoring of existing switches,and it becomes even more important when new switch concepts are being considered and evaluated.The simulation is capable of running in real time or faster meaning designs can be iterated and checked interactively.The paper describes the modelling approach,demonstrates the methodology by developing the system model for a novel“REPOINT”switch system,and evaluates the system level performance against the dynamic performance requirements for the switch.In the context of that case study,it is found that the proposed new actuation system as designed can meet(and exceed)the system performance requirements,and that the fault tolerance built into the actuation ensures continued operation after a single actuator failure.
基金gratefully acknowledge the finan-cial support of the EPSRC’s DTE Network+(EP/S032053/1)and the RSSB(COF-IPS-02).
文摘A near-term strategy to reduce emissions from rail vehicles,as a path to full electrification for maximal decarbonisation,is to partially electrify a route,with the remainder of the route requiring an additional self-powered traction option.These rail vehicles are usually powered by a diesel engine when not operating on electrified track and are referred to as bi-mode vehicles.This paper analyses the benefits of discontinuous electrification compared to continuous electrification using the CO_(2)estimates from a validated high-fidelity bi-mode(diesel-electric)rail vehicle model.This analysis shows that 50%discontinuous electrification provides a maximum of 54%reduction in operational CO_(2)emissions when compared to the same length of continuously electrified track.The highest emissions savings occurred when leaving train stations where vehicles must accelerate quickly to line speed.These results were used to develop a linear regression model for fast estimation of CO_(2)emissions from diesel running and electrification benefits.This model was able to estimate the CO_(2)emissions from a route to within 10%of that given by the high-fidelity model.Finally,additional considerations such as cost and the embodied CO_(2)in electrification infrastructure were analysed to provide a comparison between continuous and discontinuous electrification.Discontinuous electrification can cost up to 56%less per reduction in lifetime emissions than continuous electrification and can save up to 2.3 times more lifetime CO_(2)per distance electrified.
