The growing demand for capacity has prompted the rail industry to explore next-generation train control systems,such as train autonomous operation control systems,which transmit real-time information between trains wi...The growing demand for capacity has prompted the rail industry to explore next-generation train control systems,such as train autonomous operation control systems,which transmit real-time information between trains with the help of train-to-train communication.The communication delay affects the operation of the system.In addition,the train monitors real-time traffic information through on-board sensors.However,no measurement can be perfect,including sensors,which are affected by factors such as railway geometry and weather conditions.The sensor detection error is uncertain,resulting in multiple information uncertainties.Therefore,this paper proposes a train-following model based on the full velocity difference model by considering multiple information uncertainties and communication delay time to describe the autonomous operation of the train under a train autonomous operation control system.Based on this trainfollowing model,a stability analysis and numerical simulation of train traffic flow are carried out.The results show that when the velocity measured by the sensor is smaller than the real velocity or the headway monitored by the sensor is greater than the real headway,the delay will increase and continue to propagate and accumulate backward,resulting in blockage.Otherwise,the opposite occurs.These findings suggest that the effects of multiple information uncertainties are two-sided,depending on the degree of uncertainty of velocity information and headway information.In addition,communication delay time has little effect on train flow and delay.展开更多
The port railway operation in Germany and Europe is not least due to its long history of technological and regulatory developments characterized by a high number of players and a lack of comprehensive planning and opt...The port railway operation in Germany and Europe is not least due to its long history of technological and regulatory developments characterized by a high number of players and a lack of comprehensive planning and optimization of all relevant processes.Innovative technologies and business processes are therefore useful and needed to achieve key steps on the way to an overall optimization of rail transport within global supply chains.A substantial part of the European rail freight transport has its origin or its destination in an inland or sea port.Considering the railway system,ports play a more important role for urgently needed innovations than the pure interfaces between sea and land transport.Especially ports with their own railway system have an own responsibility in this matter.Insofar the goal of the Bremen Port Railway—which already now has a leading share of railway in modal split in Europe—is to exploit the opportunities offered by digitalization.Significant steps for this are the optimization and gradually automatization of rail operational processes on the last mile including modern and transparent IT systems and the designing of autonomous shunting processes.Together with research partners ISL(Institute of Shipping Economics and Logistics Bremen),BIBA(Bremen Institute for Production and Logistics)and IVE(Institute for Transport,Railway Construction and Operation in Brunswick)and in connection with associated business partners the project Rang-E has been applied for at the Ministry of Transport in the funding initiative IHATEC(Innovated HArbour TEChnologies)—and had won a grant to perform the proposed work.Basic thoughts are outlined in the following.展开更多
This paper introduces the sea-launch technology of a cryogenic liquid-fueled medium-lift rocket.It first reviews the current state of sea launch technology,and then gives a brief introduction of China’s New Generatio...This paper introduces the sea-launch technology of a cryogenic liquid-fueled medium-lift rocket.It first reviews the current state of sea launch technology,and then gives a brief introduction of China’s New Generation Medium-lift Launch Vehicle(NGMLV).The innovations in the NGMVL,such as responsive test and launch control,a H3 launch model,and unmanned operations,provide convenience for sea launches.Based on these innovations,this paper proposes a sea launch scheme,including the system configuration,test and launch processes,and an improved adaptive design for the rocket.Then,the launch platform is discussed in detail,which integrates the functions of sea transportation,assembly and test,as well as technical and launch areas.The layout and function divisions,fluid filling,gas supply and distribution systems,and lossless storage technology of LH2 are described in order.This breakthrough in sea launch technology will enable China to launch medium and large satellites and constellations‘both on land and sea’,especially into low-inclination Low-Earth Orbits(LEOs),and it allows China to remain competitive in the fast-paced space industry.展开更多
In view of the problem of low self-service capability of the microgrid due to the high operating cost and low capacity of the traditional battery energy storage system.In this paper,an electrothermal hybrid energy sto...In view of the problem of low self-service capability of the microgrid due to the high operating cost and low capacity of the traditional battery energy storage system.In this paper,an electrothermal hybrid energy storage model based on electricity,hydrogen and thermal energy conversion and storage is introduced,and a microgrid autonomous operational strategy is proposed.First,the addition of the power to hydrogen transfer equipment in the traditional combined heat and power(TCHP)system without battery energy storage is studied,and a micro gas turbine,electric to hydrogen transfer equipment and electric boiler based electrothermal energy storage system(ETSS)model is established.Aiming at the lowest comprehen-sive operating cost of multiple energy sources in a microgrid and maximizing the consumption of curtailed wind,the multi-objective scheduling model of an electrothermal hybrid energy storage system is established,then the multi-energy autonomous operational strategy of a microgrid is proposed.Lastly,the simulation of a multi-energy microgrid in Northeast China is taken as an example.The results of the simulation showed that compared with a combined heat and power microgrid system considering conventiona battery energy storage,a multi-energy microgrid system using electrothermal hybrid energy storage has better flexibility and economy,and can improve wind power accommodation.展开更多
基金supported by Beijing Natural Science Foundation(Grant No.L231009)the National Natural Science Foundation of China(Grant No.72288101)the Fundamental Research Funds for the Central Universities(Grant No.2022JBZY017)。
文摘The growing demand for capacity has prompted the rail industry to explore next-generation train control systems,such as train autonomous operation control systems,which transmit real-time information between trains with the help of train-to-train communication.The communication delay affects the operation of the system.In addition,the train monitors real-time traffic information through on-board sensors.However,no measurement can be perfect,including sensors,which are affected by factors such as railway geometry and weather conditions.The sensor detection error is uncertain,resulting in multiple information uncertainties.Therefore,this paper proposes a train-following model based on the full velocity difference model by considering multiple information uncertainties and communication delay time to describe the autonomous operation of the train under a train autonomous operation control system.Based on this trainfollowing model,a stability analysis and numerical simulation of train traffic flow are carried out.The results show that when the velocity measured by the sensor is smaller than the real velocity or the headway monitored by the sensor is greater than the real headway,the delay will increase and continue to propagate and accumulate backward,resulting in blockage.Otherwise,the opposite occurs.These findings suggest that the effects of multiple information uncertainties are two-sided,depending on the degree of uncertainty of velocity information and headway information.In addition,communication delay time has little effect on train flow and delay.
文摘The port railway operation in Germany and Europe is not least due to its long history of technological and regulatory developments characterized by a high number of players and a lack of comprehensive planning and optimization of all relevant processes.Innovative technologies and business processes are therefore useful and needed to achieve key steps on the way to an overall optimization of rail transport within global supply chains.A substantial part of the European rail freight transport has its origin or its destination in an inland or sea port.Considering the railway system,ports play a more important role for urgently needed innovations than the pure interfaces between sea and land transport.Especially ports with their own railway system have an own responsibility in this matter.Insofar the goal of the Bremen Port Railway—which already now has a leading share of railway in modal split in Europe—is to exploit the opportunities offered by digitalization.Significant steps for this are the optimization and gradually automatization of rail operational processes on the last mile including modern and transparent IT systems and the designing of autonomous shunting processes.Together with research partners ISL(Institute of Shipping Economics and Logistics Bremen),BIBA(Bremen Institute for Production and Logistics)and IVE(Institute for Transport,Railway Construction and Operation in Brunswick)and in connection with associated business partners the project Rang-E has been applied for at the Ministry of Transport in the funding initiative IHATEC(Innovated HArbour TEChnologies)—and had won a grant to perform the proposed work.Basic thoughts are outlined in the following.
基金supported by the Research on Design Technology of Sea Launch and Recovery Platform(Ship),one High Tech Research Project of MIIT,China。
文摘This paper introduces the sea-launch technology of a cryogenic liquid-fueled medium-lift rocket.It first reviews the current state of sea launch technology,and then gives a brief introduction of China’s New Generation Medium-lift Launch Vehicle(NGMLV).The innovations in the NGMVL,such as responsive test and launch control,a H3 launch model,and unmanned operations,provide convenience for sea launches.Based on these innovations,this paper proposes a sea launch scheme,including the system configuration,test and launch processes,and an improved adaptive design for the rocket.Then,the launch platform is discussed in detail,which integrates the functions of sea transportation,assembly and test,as well as technical and launch areas.The layout and function divisions,fluid filling,gas supply and distribution systems,and lossless storage technology of LH2 are described in order.This breakthrough in sea launch technology will enable China to launch medium and large satellites and constellations‘both on land and sea’,especially into low-inclination Low-Earth Orbits(LEOs),and it allows China to remain competitive in the fast-paced space industry.
基金This work was supported by the National Key Research and Development Program of China(No.2017YFB0902100).
文摘In view of the problem of low self-service capability of the microgrid due to the high operating cost and low capacity of the traditional battery energy storage system.In this paper,an electrothermal hybrid energy storage model based on electricity,hydrogen and thermal energy conversion and storage is introduced,and a microgrid autonomous operational strategy is proposed.First,the addition of the power to hydrogen transfer equipment in the traditional combined heat and power(TCHP)system without battery energy storage is studied,and a micro gas turbine,electric to hydrogen transfer equipment and electric boiler based electrothermal energy storage system(ETSS)model is established.Aiming at the lowest comprehen-sive operating cost of multiple energy sources in a microgrid and maximizing the consumption of curtailed wind,the multi-objective scheduling model of an electrothermal hybrid energy storage system is established,then the multi-energy autonomous operational strategy of a microgrid is proposed.Lastly,the simulation of a multi-energy microgrid in Northeast China is taken as an example.The results of the simulation showed that compared with a combined heat and power microgrid system considering conventiona battery energy storage,a multi-energy microgrid system using electrothermal hybrid energy storage has better flexibility and economy,and can improve wind power accommodation.
