In contrast to the conventional direct current railway electrification system(DC-RES),the medium voltage direct current(MVDC)-RES is considered promising for long-distance high-speed corridors.In the MVDC-RES,traction...In contrast to the conventional direct current railway electrification system(DC-RES),the medium voltage direct current(MVDC)-RES is considered promising for long-distance high-speed corridors.In the MVDC-RES,traction substations(TSSs)are placed much farther and train loads are much heavier than in the conventional DC-RES.Hence,the MVDC-RES brings a drastic change in catenary voltage,TSS spacing,and train loading,which affects rail potential and stray current.In this connection,this work performs some significant quantitative analysis of rail potential and stray current in the MVDC-RES environment.An MVDC simulation model is proposed and different grounding schemes are analyzed for a single-train and two TSSs scenario as well as for a multi-train multi-TSS scenario.According to the simulation and analysis,the maximum values of rail potential and stray current at MVDC-RES distances and the maximum safe distance between adjacent TSSs are determined.展开更多
In the process of leapfrog development of national railway engineering, the speed of railway electrification development is faster and faster. In the process of building modern electrified railway engineering in new c...In the process of leapfrog development of national railway engineering, the speed of railway electrification development is faster and faster. In the process of building modern electrified railway engineering in new cities, the original railway lines should also be electrified and improved, which has become the core content of railway electrification development in China. Continuous power supply by catenary is an important part of electrified railway operation, so the reconstruction project should focus on catenary. The running speed of electrified train is very fast, which will bring strong vibration to the catenary during operation, and the foundation pillar will bear huge load in an instant. This requires that the catenary can reasonably disperse the load, not only protect the bearing capacity of the upper part, but also make the lower foundation more stable. Therefore, in order to carry out the railway electrification transformation smoothly, it is necessary to ensure the normal operation of the existing line, scientifically and reasonably select the transformation mode of catenary and foundation form, so as to ensure the stability of subgrade and pillar, control the vibration of catenary within the minimum range, and ensure the smooth completion of improvement construction.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
Because the high-speed railway line design is designed in accordance with the long-term traffic volume, the line operation in the early and medium term traffic volume is small, leading to the traction power supply sys...Because the high-speed railway line design is designed in accordance with the long-term traffic volume, the line operation in the early and medium term traffic volume is small, leading to the traction power supply system in the whole line of equipment utilization is relatively low, mainly concentrated in the traction substation traction transformer capacity utilization rate is low. By optimizing the capacity, quantity and position of the equipment in the traction power supply system, the energy consumption of the whole line can be reduced and the utilization rate of the equipment can be increased. This paper studies and analyzes the application of intelligent traction substation in electrified railway for reference.展开更多
In recent years,the achievement of a renewable and sustainable traction power supply system(TPSS)in the rail sector has become a significant challenge.Focusing on this issue,this paper firstly provides a comprehensive...In recent years,the achievement of a renewable and sustainable traction power supply system(TPSS)in the rail sector has become a significant challenge.Focusing on this issue,this paper firstly provides a comprehensive overview and classification of the state-of-art TPSSs in DC and AC railway.Then,together with low voltage(LV)DC,medium voltage(MV)DC,LV AC,and hybrid AC/DC interconnected microgrid(IMGs),various architectures of resilient TPSSs are proposed for renewable energy integration into DC and AC railway.The resilient TPSS offers on-site access and local consumption of renewable sources alongside railways and guarantees a sustainable power supply in the case of grid disturbances and failures,e.g.,voltage unbalance,harmonic and violent fluctuation,power outage,and extreme events in the wake of natural disasters and extreme weather.This approach also helps facilitate the development of the next generation TPSSs for enhanced flexibility and sustainability.Then,based on a comparative analysis of different resilient TPSSs,a brief outlook of the future trend is given.Finally,it is concluded that resilient TPSS provides a universal solution for both renewable energy integration and high-quality power supply against grid disturbances and failures.展开更多
Innovative advancement in power electronics is reshaping the conventional high-voltage transmission systems and has also opened a new paradigm for researchers to consider its benefits in the railway electrification sy...Innovative advancement in power electronics is reshaping the conventional high-voltage transmission systems and has also opened a new paradigm for researchers to consider its benefits in the railway electrification system(RES).In this regard,the medium-voltage direct current RES(MVDC-RES)is a key area of interest nowadays.In this paper,a secondary energy source(SES)consisting of renewable energies(REs)and energy storage systems(ESSs)is proposed to solve the issues of catenary voltage regulation,rail potential,and stray current in the MVDC-RES.Some of the major integration topologies of the SES are analyzed for MVDC-RES and the most effective one is proposed and implemented.The voltage at the point of connection(PoC)of the SES is used as a reference for controlling different operation modes of REs and ESSs.Moreover,feedforward control is used at the ESS converter to attain the quick response from the batteries for the desired operation.The proposed scheme improves the catenary voltage,and reduces the rail potential and stray current.Besides,the scheme provides higher energy density and reduces line losses.Simulation results are provided to validate the operation modes and advantages of the proposed scheme.展开更多
文摘In contrast to the conventional direct current railway electrification system(DC-RES),the medium voltage direct current(MVDC)-RES is considered promising for long-distance high-speed corridors.In the MVDC-RES,traction substations(TSSs)are placed much farther and train loads are much heavier than in the conventional DC-RES.Hence,the MVDC-RES brings a drastic change in catenary voltage,TSS spacing,and train loading,which affects rail potential and stray current.In this connection,this work performs some significant quantitative analysis of rail potential and stray current in the MVDC-RES environment.An MVDC simulation model is proposed and different grounding schemes are analyzed for a single-train and two TSSs scenario as well as for a multi-train multi-TSS scenario.According to the simulation and analysis,the maximum values of rail potential and stray current at MVDC-RES distances and the maximum safe distance between adjacent TSSs are determined.
文摘In the process of leapfrog development of national railway engineering, the speed of railway electrification development is faster and faster. In the process of building modern electrified railway engineering in new cities, the original railway lines should also be electrified and improved, which has become the core content of railway electrification development in China. Continuous power supply by catenary is an important part of electrified railway operation, so the reconstruction project should focus on catenary. The running speed of electrified train is very fast, which will bring strong vibration to the catenary during operation, and the foundation pillar will bear huge load in an instant. This requires that the catenary can reasonably disperse the load, not only protect the bearing capacity of the upper part, but also make the lower foundation more stable. Therefore, in order to carry out the railway electrification transformation smoothly, it is necessary to ensure the normal operation of the existing line, scientifically and reasonably select the transformation mode of catenary and foundation form, so as to ensure the stability of subgrade and pillar, control the vibration of catenary within the minimum range, and ensure the smooth completion of improvement construction.
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.
文摘Because the high-speed railway line design is designed in accordance with the long-term traffic volume, the line operation in the early and medium term traffic volume is small, leading to the traction power supply system in the whole line of equipment utilization is relatively low, mainly concentrated in the traction substation traction transformer capacity utilization rate is low. By optimizing the capacity, quantity and position of the equipment in the traction power supply system, the energy consumption of the whole line can be reduced and the utilization rate of the equipment can be increased. This paper studies and analyzes the application of intelligent traction substation in electrified railway for reference.
基金supported in part by the National Natural Science Foundation of China(No.51807182).
文摘In recent years,the achievement of a renewable and sustainable traction power supply system(TPSS)in the rail sector has become a significant challenge.Focusing on this issue,this paper firstly provides a comprehensive overview and classification of the state-of-art TPSSs in DC and AC railway.Then,together with low voltage(LV)DC,medium voltage(MV)DC,LV AC,and hybrid AC/DC interconnected microgrid(IMGs),various architectures of resilient TPSSs are proposed for renewable energy integration into DC and AC railway.The resilient TPSS offers on-site access and local consumption of renewable sources alongside railways and guarantees a sustainable power supply in the case of grid disturbances and failures,e.g.,voltage unbalance,harmonic and violent fluctuation,power outage,and extreme events in the wake of natural disasters and extreme weather.This approach also helps facilitate the development of the next generation TPSSs for enhanced flexibility and sustainability.Then,based on a comparative analysis of different resilient TPSSs,a brief outlook of the future trend is given.Finally,it is concluded that resilient TPSS provides a universal solution for both renewable energy integration and high-quality power supply against grid disturbances and failures.
文摘Innovative advancement in power electronics is reshaping the conventional high-voltage transmission systems and has also opened a new paradigm for researchers to consider its benefits in the railway electrification system(RES).In this regard,the medium-voltage direct current RES(MVDC-RES)is a key area of interest nowadays.In this paper,a secondary energy source(SES)consisting of renewable energies(REs)and energy storage systems(ESSs)is proposed to solve the issues of catenary voltage regulation,rail potential,and stray current in the MVDC-RES.Some of the major integration topologies of the SES are analyzed for MVDC-RES and the most effective one is proposed and implemented.The voltage at the point of connection(PoC)of the SES is used as a reference for controlling different operation modes of REs and ESSs.Moreover,feedforward control is used at the ESS converter to attain the quick response from the batteries for the desired operation.The proposed scheme improves the catenary voltage,and reduces the rail potential and stray current.Besides,the scheme provides higher energy density and reduces line losses.Simulation results are provided to validate the operation modes and advantages of the proposed scheme.
