Current status and reflection on the development of high-speed maglev transportation

Purpose–High-speed maglev technology can address the issues of adhesion,friction,vibration and highspeed current collection in traditional wheel-rail systems,making it an important direction for the future development of high-speed rail technology.Design/methodology/approach–This paper elaborates on the demand and significance of developing high-speed maglev technology worldwide and examines the current status and technological maturity of several major high-speed maglev systems globally.Findings–This paper summarizes the challenges in the development of high-speed maglev railways in China.Based on this analysis,it puts forward considerations for future research on high-speed maglev railways.Originality/value–This paper describes the development status and technical maturity of several major high-speed maglev systems in the world for the first time,summarizes the existing problems in the development of China’s high-speed maglev railway and on this basis,puts forward the thinking of the next research of China’s high-speed maglev railway.

Aerodynamic Features of High-Speed Maglev Trains with Different Marshaling Lengths Running on a Viaduct under Crosswinds

The safety and stability of high-speed maglev trains traveling on viaducts in crosswinds critically depend on their aerodynamic characteristics.Therefore,this paper uses an improved delayed detached eddy simulation(IDDES)method to investigate the aerodynamic features of high-speed maglev trains with different marshaling lengths under crosswinds.The effects of marshaling lengths(varying from 3-car to 8-car groups)on the train’s aerodynamic performance,surface pressure,and the flow field surrounding the train were investigated using the three-dimensional unsteady compressible Navier-Stokes(N-S)equations.The results showed that the marshaling lengths had minimal influence on the aerodynamic performance of the head and middle cars.Conversely,the marshaling lengths are negatively correlated with the time-average side force coefficient(CS)and time-average lift force coefficient(Cl)of the tail car.Compared to the tail car of the 3-car groups,the CS and Cl fell by 27.77%and 18.29%,respectively,for the tail car of the 8-car groups.It is essential to pay more attention to the operational safety of the head car,as it exhibits the highest time average CS.Additionally,the mean pressure difference between the two sides of the tail car body increased with the marshaling lengths,and the side force direction on the tail car was opposite to that of the head and middle cars.Furthermore,the turbulent kinetic energy of the wake structure on the windward side quickly decreased as marshaling lengths increased.

Upgrade of Transportation Infrastructure and Siting of Polluting Enterprises:The Case of High-Speed Railway Launch in China

With the quasi-natural experiment of the launching of high-speed railways in Chinese cities,this paper empirically investigated the effects of the upgrade of the transportation infrastructure on the site selection of polluting enterprises.We found that although the launching of a high-speed railway generally has a negative impact on the siting of polluting enterprises:(i)While there was a significant decrease in polluting enterprises of a private and other nature,the reduction in overseas-funded and state-owned enterprises was insignificant;(ii)while the launching of a high-speed railway greatly restrained the entry of polluting enterprises in the eastern region,large cities and more developed cities,this was followed by the movement of more polluting enterprises to the central and western regions,small and medium-sized cities and less developed cities;(iii)there was a significant decrease in polluting enterprises in environmentally conscious cities after the launching of a high-speed railway.This paper also found that infrastructure upgrade may influence the siting of polluting enterprises through the following:Environmental cleanness,factor concentration and spatial integration.Government authorities and market entities should be fully aware of and attach great importance to how the transportation infrastructure influences the site selection of businesses,as this is of great significance for China’s regional development planning,local business climate and investment planning,environmental protection,and other related policymaking initiatives.

Analyze China High-Speed Railway Ticket for Spring Transportation from the Perspective of Microeconomics

In recent ten years, the rapid development of China high-speed railway is called "China miracle", and it not only provides great convenience for people's daily life trip, but also greatly promotes the economic development. However, the annual spring transportation in the special period is still a great challenge to high-speed railway transportation, and this paper analyzes the high-speed railway ticket for spring transportation from the perspective of microeconomics, and then thinks for the solution. This paper specifically analyzes the problem that demand exceeds supply for high-speed railway ticket by using the theories of the demand elasticity of supply and demand and the influence of price on supply and demand, monopoly markets. In addition, opportunity cost, incomplete information and other economic principles are used to think about the theoretical reasons for the difficulty of buying tickets during the spring transportation. I have given my understanding for the two problems owned by China spring transportation, and the corresponding countermeasures and suggestions. For example, speed up the development of substitutes and carry out the mechanism of price fluctuation;In the ticket refunding mechanism, this paper boldly conceives the method to relieve the pressure through a reasonable and scientific ticket refunding mechanism. Finally, this paper starts from the source and find the key point to solve the problem of spring transportation in China by breaking the urban-rural dual structure. Hereafter the final conclusion was drawn: Although there are some problems to cope with the spring transport for the current China high-speed railway, it is believed that in the near future, the difficulty of buying a ticket in spring transportation will no longer hinder the homecoming of wanderers.

Motion stability of high-speed maglev systems in consideration of aerodynamic effects: a study of a single magnetic suspension system

In this study, the intrinsic mechanism of aerodynamic effects on the motion stability of a high-speed maglev system was investigated. The concept of a critical speed for maglev vehicles considering the aerodynamic effect is proposed. The study was carried out based on a single magnetic suspension system, which is convenient for proposing relevant concepts and obtaining explicit expressions. This study shows that the motion stability of the suspension system is closely related to the vehicle speed when aerodynamic effects are considered. With increases of the vehicle speed, the stability behavior of the system changes. At a certain vehicle speed,the stability of the system reaches a critical state, followed by instability. The speed corresponding to the critical state is the critical speed. Analysis reveals that when the system reaches the critical state, it takes two forms, with two critical speeds, and thus two expressions for the critical speed are obtained. The conditions of the existence of the critical speed were determined, and the effects of the control parameters and the lift coefficient on the critical speed were analyzed by numerical analysis. The results show that the first critical speed appears when the aerodynamic force is upward,and the second critical speed appears when the aerodynamic force is downward. Moreover, both critical speeds decrease with the increase of the lift coefficient.

Coupling vibration analysis of high-speed maglev train-viaduct systems with control loop failure

The risk of failure of the control loop can occur when a high-speed maglev train runs on viaduct.Meanwhile,the failure of the levitation magnets which balances the gravity of the maglev train could cause the train collision with track.To study the dynamic response of the train and the viaduct when the levitation magnet control loop failure occurs,a high-speed maglev train-viaduct coupling model,which includes a maglev controller fitted by measured force-gap data and considers the actual structure of train and viaduct,is established.Then the accuracy and effectiveness of the established approach are validated by comparing the computed dynamic responses and frequencies with the measurement results.After that,the dynamic responses of maglev train and viaduct are discussed under normal operation and control loop failures,and the most disadvantageous combination of control loop failures is obtained.The results show that when a single control loop fails,it only has a great influence on the failed electromagnet,and the maglev response of adjacent electromagnets has no obvious change and no collision occurs.But there is a risk of rail collisions when the dual control loop fails.

Levitation mechanism modelling for maglev transportation system

A novel maglev transportation system was proposed for large travel range ultra precision motion.The system consists of a levitation subsystem and a propulsion subsystem.During the propulsion subsystem driving the moving platform along the guideway,the levitation subsystem uses six pairs of electromagnets to steadily suspend the moving platform over the guideway.The model of the levitation system,which is a typical nonlinear multi-input multi-output coupling system and has many inner nonlinear coupling characteristics,was deduced.For testifying the model,the levitation mechanism was firstly controlled by proportional-integral-differential(PID) control,and then a lot of input-output data were collected for model parameter identification.The least-square parameter identification method was used.The identification results prove that the model is feasible and suitable for the real system.

KL-SG High-Speed Rail-a catalyst for national economic development Sri Viknesh Permalu and Karthigesu Nagarajoo

Purpose-In an increasingly interconnected world,transportation infrastructure has emerged as a critical determinant of economic growth and global competitiveness.High-speed rail(HSR),characterized by its exceptional speed and efficiency,has garnered widespread attention as a transformative mode of transportation that transcends borders and fosters economic development.The Kuala Lumpur-Singapore(KL-SG)HSR project stands as a prominent exemplar of this paradigm,symbolizing the potential of HSR to serve as a catalyst for national economic advancement.Design/methodologylapproach-This paper is prepared to provide an insight into the benefits and advantages of HSR based on proven case studies and references from global HSRs,including China,Spain,France and Japan.Findings-The findings that have been obtained focus on enhanced connectivity and accessibility,attracting foreign direct investment,revitalizing regional economies,urban development and city regeneration,boosting tourism and cultural exchange,human capital development,regionai integration and environmental and sustainability benefits.Originality/value-The KL-SG HSR,linking Kuala Lumpur and Singapore,epitomizes the potential for HSR to be a transformative agent in the realm of economic development.This project encapsulates the aspirations of two dynamic Southeast Asian economies,united in their pursuit of sustainable growth,enhanced connectivity and global competitiveness.By scrutinizing the KLSG High-Speed Rail through the lens of economic benchmarking,a deeper understanding emerges of how such projects can drive progress in areas such as cross-border trade,tourism,urban development and technological innovation.

Electromagnetic Analysis and Optimization of High-speed Maglev Linear Synchronous Motor Based on Field-circuit Coupling

High speed maglev train has become a new non-contact transportation mode mainly studied in recent years because of its non-sticking and high speed characteristics.Firstly,the finite element model of the long stator linear synchronous motor(LSM)is established based on the structure of the test prototype.After calculation,it is compared with the experimental data and verified.On this basis,a field-circuit coupling model based on inverter circuit is established,and the influence of carrier wave ratio change on the output characteristics of LSM is calculated and analyzed.Finally,the filter circuit is introduced into the field-circuit coupling model,and the influence of the filter circuit on the output characteristics of the LSM is compared and analyzed.

A study on aerodynamic noise characteristics of a high-speed maglev train with a speed of 600 km/h

Purpose–This study aims to explore the formation mechanism of aerodynamic noise of a high-speed maglev train and understand the characteristics of dipole and quadrupole sound sources of the maglev train at different speed levels.Design/methodology/approach–Based on large eddy simulation(LES)method and Kirchhoff–Ffowcs Williams and Hawkings(K-FWH)equations,the characteristics of dipole and quadrupole sound sources of maglev trains at different speed levels were simulated and analyzed by constructing reasonable penetrable integral surface.Findings–The spatial disturbance resulting from the separation of the boundary layer in the streamlined area of the tail car is the source of aerodynamic sound of the maglev train.The dipole sources of the train are mainly distributed around the radio terminals of the head and tail cars of the maglev train,the bottom of the arms of the streamlined parts of the head and tail cars and the nose tip area of the streamlined part of the tail car,and the quadrupole sources are mainly distributed in the wake area.When the train runs at three speed levels of 400,500 and 600 km$h1,respectively,the radiated energy of quadrupole source is 62.4%,63.3%and 71.7%,respectively,which exceeds that of dipole sources.Originality/value–This study can help understand the aerodynamic noise characteristics generated by the high-speed maglev train and provide a reference for the optimization design of its aerodynamic shape.

Key vacuum technology issues to be solved in evacuated tube transportation

Evacuated tube transportation （ETT） will be one of the ultra-large-scale vacuum application areas. This paper lists some key vacuum technology issues in ETT： （1） how to construct ultra-large-scale vacuum chamber with lower cost and high reliability, （2） how to evacuate gas out of the ETT tube in short time, （3） how to release heat or reduce temperature in the vacuum tube, （4） how to avoid vacuum discharge, （5） how to make vehicles with airproof shells and life support system, and （6） how to detect leaks and find leak positions efficiently. At the same time, some solutions are proposed.

Regional container transportation system for Northeast Asia economic cooperation in the 21^(st) century

In this paper, the roles of infrastructure development and transportation coordination for Northeast Asian economic cooperation are discussed. It would be necessary to establish an efficient transportation network as soon as possible. 'Hub-and-Spoke'transportation system and China-Korean peninsula railway container transportation system might be more significant for regional economic cooperation.

Design consideration of a super-high speed high temperature superconductor maglev evacuated tube transport (I)

The super-high speed high temperature superconductor （HTS） maglev evacuated tube transport （ETT） is a promising transport mode for the future. As a key component of the HTS maglev vehicle, the permanent magnet guide- ways （PMGs） with different geometrical configurations and iron yoke widths are analyzed by finite element method （FEM）. The levitation force of a single onboard HTS maglev device over the designed PMG at different field cooling heights （FCH） is measured by magnetic levitation measurement system. Based on the designed PMG and experimental results, a preliminary scheme of subterranean super-high speed HTS maglev ETT is described in this paper. The HTS maglev ETT is mainly composed of an evacuated tube, HTS maglev vehicle, PMG, propulsion system, station, emergency rescue system, etc. In addition, a subterranean tube that consists of foundation tube and vacuum airproof layer is introduced. In order to convert the stress caused by the air pressure difference between inside and outside of the vehicle, a multi-circular vehicle body is designed. The vehicle is driven by a linear motor propulsion system under the control of a ground controlling system. The scheme of long-distance super-high speed passenger transportation is accomplished by the connection of different vehicles.

System architecture and basic platform for intelligent high-speed railway

Purpose-This paper aims to provide top-level design and basic platform for intelligent application in China high-speed railway.Design/methodology/approach-Based on the analysis for the future development trends of world railway,combined with the actual development needs in China high-speed railway,The definition and scientific connotation of intelligent high-speed railway(IHSR)are given at first,and then the system architecture of IHSR are outlined,including 1 basic platform,3 business sectors,10 business fields,and 18 innovative applications.At last,a basic platform with cloud edge integration for IHSR is designed.Findings-The rationality,feasibility and implementability of the system architecture of IHSR have been verified on and applied to the Beijing-Zhangjiakou high-speed railway,providing important support for the construction and operation of the world’s first IHSR.Originality/value-This paper systematically gives the definition and connotation of the IHSR and put forward the system architecture of IHSR for first time.It will play the most important role in the design,construction and operation of IHSR.

Vibration analysis of maglev three-span rigid frame bridge considering magnetic force

The dynamic interaction between the maglev vehicle and the three-span rigid frame bridge is discussed. With the consideration of magnetic force, the interaction model is developed. Numerical simulations are performed to study the dynamic characteristics of the bridge during vehicle movement along the bridge. The results show that a reasonable value of the linear stiffness ratio of columns to beams is between 2. 0 and 3.0. The dynamic responses of the bridge are aggravated with the decrease in bending rigidity and the increase in vehicle speed and the span ratio of the bridge. It is suggested that a definite way is to control impact coefficients and acceleration in the dynamic design of the bridge. It is unsuitable to adopt the moving load model and the moving mass model in the design. The proposed results can serve in the design of high-speed maglev three-span rigid frame bridges.

Hierarchical model updating for high-speed maglev vehicle/guideway coupled system based on multiobjective optimization

The high-speed maglev vehicle/guideway coupled model is an essential simulation tool for investigating vehicle dynamics and mitigating coupled vibration.To improve its accuracy efficiently,this study investigated a hierarchical model updating method integrated with field measurements.First,a high-speed maglev vehicle/guideway coupled model,taking into account the real effect of guideway material properties and elastic restraint of bearings,was developed by integrating the finite element method,multi-body dynamics,and electromagnetic levitation control.Subsequently,simultaneous in-site measurements of the vehicle/guideway were conducted on a high-speed maglev test line to analyze the system response and structural modal parameters.During the hierarchical updating,an Elman neural network with the optimal Latin hypercube sampling method was used to substitute the FE guideway model,thus improving the computational efficiency.The multi-objective particle swarm optimization algorithm with the gray relational projection method was applied to hierarchically update the parameters of the guideway layer and magnetic force layer based on the measured modal parameters and the electromagnet vibration,respectively.Finally,the updated coupled model was compared with the field measurements,and the results demonstrated the model’s accuracy in simulating the actual dynamic response,validating the effectiveness of the updating method.

Electromagnetic characteristic analysis and design of a linear motor used for ultra-high-speed EMS maglev train

The operating speed of the commercial electromagnetic suspension(EMS)maglev train has been over 430 km/h,making it the fastest means of land transportation.With the increasing demands of people traveling,it is necessary to further improve the operating speed of maglev trains.Aiming to examine whether the existing EMS system can meet the requirements of ultra-highspeed operation(more than 600 km/h),the electromagnetic characteristics of an EMS linear motor under the operating speed of 600–1000 km/h fed by a square-wave voltage supply is investigated in this article.First,an electromagnetic field model of the EMS system under the square-wave voltage supply is established to investigate its electromagnetic performance,e.g.,the characteristics of phase current,the magnetic flux density,and the electromagnetic force.Second,the relationship between the harmonic components of the air-gap magnetic flux density and electromagnetic force is investigated using the two-dimensional fast Fourier transform(2D-FFT)to reveal the mechanism of electromagnetic force ripple.Third,to address the issues of excessive armature current density and significant electromagnetic force ripple,the linear motor is re-designed by enlarging the stator slot area and reshaping the mover's main magnetic poles.Furthermore,the Taguchi method is used to further improve the electromagnetic characteristics of the linear electric motor.Finally,the effectiveness of the proposed optimal design is validated by the finite-element analysis(FEA)based co-simulation.

Spatial relationship of high-speed transportation construction and land-use efficiency and its mechanism:Case study of Shandong Peninsula urban agglomeration

Land-use efficiency is low for the urban agglomeration of China. High-speed transportation construction has been an important factor driving land use change. It is critically important to explore the spatial relationship between the high-speed transportation superiority degree and land-use efficiency. We built a model to evaluate the benefits of convenient high-speed transportation using the relative density of highways and the distance from high-speed rail stations and airports as a metric. We used 42 counties of the Shandong Peninsula urban agglomeration as an example. Land-use efficiency was calculated by a DEA model with capital, labor, economic benefits and environmental benefits as input and output factors. We examined the spatial relationships between high-speed transport superiority degree and land-use efficiency and obtained the following results. First, there are significant spatial differences in the relationships between the high-speed transportation superiority degree and land-use efficiency. Taking the two major cities of Jinan and Qingdao as the hubs, the core surrounding counties show significant spatial relationship between land-use efficiency and the high-speed transportation superiority degree. Spatial correlation declines as the distance from the hubs increases. Land-use efficiency is less than high-speed transportation convenience in areas along the transportation trunks that are distant from the hub cities. Correlation is low in areas that are away from both hub cities and transportation trunk routes. Second, high-speed transportation has a positive relationship with land-use efficiency due to the mechanism of element agglomeration exogenous growth. Third, high-speed transportation facilitates the flow of goods, services and technologies between core cities and peripheral cities as space spillover(the hub effect). This alters the spatial pattern of regional land-use efficiency. Finally, the short-board effect caused by decreased high-speed transport construction can be balanced by highway construction and the proper node layouts of high-speed rail stations and airports, resulting in a well-balanced spatial pattern of land-use efficiency.

Vibration analysis of maglev three-span continuous guideway considering control system

The dynamic interaction between maglev vehicle and three-span continuous guideway is discussed. With the consideration of control system, the dynamic interaction model has been developed. Numerical simulation has been performed to study dynamic characteristics of the guideway. The results show that bending rigidity, vehicle speed, span ratio and primary frequency all have important influences on the dynamic characteristics of the guideway and there is no distinct trend towards resonance vibration when fl/（v/l） equals 1.0. The definite way is to control impact coefficient and acceleration of the guideway. The conclusions can serve the design of high-speed maglev three-span continuous guideway.

Vibration Analysis of Continuous Maglev Guideway Considering the Magnetic Levitation System

The dynamic interaction between moving vehicles and two-span continuous guideway was discussed. With the consideration of the magnetic levitation system, the maglev vehicle/guideway dynamic interaction model was developed. Numerical simulation was performed to understand dynamic characteristics of the guideway used in practice. The results show that vehicle speed, span length and primary frequency of the guideway have an important influence on the dynamic responses of the guideway and there is no distinct trend towards resonance vibration when fl equals 1.0. The definite way is to control the impact coefficient and acceleration of the guideway. The conclusions can serve the design of high speed maglev guideway.