Academic literature on the topic 'Maglev rail system'

The low-to-medium-speed maglev train is stably suspended near the rated suspension gap. The suspension force acts directly on the track and is transmitted to the bridge. The maglev track structure is novel, and the influence mechanism of the track structure on the coupled vibration of the maglev train-bridge system is unknown. Therefore, in this study, we propose vertical dynamic interaction models of the low-to-medium-speed maglev train-bridge system and the low-to-medium-speed maglev train-track-bridge system to analyse the influence mechanism of the maglev track structure on the vertical dynamic interaction of the low-to-medium-speed maglev train-bridge system. The vibration characteristics of the F-rail and the influence mechanism of the track structure on the dynamic responses of the bridge are discussed in detail. The study verifies that the local deformation of the F-rail is self-evident and cannot be ignored. In addition, the influence of the F-rail on the dynamic interaction of the maglev train-bridge system is mainly reflected in two aspects: first, the vibration of the bridge in the high-frequency band increases due to the high frequency and intensive local vibration of the F-rail itself. Second, the vibrations of the bridge and the F-rail in the low-frequency band increase due to the periodic irregularities caused by the local deformation of the F-rail. In this study, we consider the vertical dynamic interaction model of the low-to-medium-speed maglev train-track-bridge system.

Background: For medium and low speed maglev transportation system, the eddy current will be induced in rail, which is made of solid steel, while the train is running. The levitation force of electromagnets will be weakened by the magnetic field generated by eddy current in the rail, especially at the position of the forefront electromagnets. With the increase of train running speed, the eddy current effect will also increase, which will reach 30 % at 100 km/h, and which will directly affect the levitation stability of the train during high-speed running. Put it another way, it will limit the further improvement of the running speed of the medium and low speed maglev train.
 Aim: In order to solve the above problem, and compensate the levitation force reduced by the eddy current effect.
 Methods: The FEA method is used to obtain the magnetic field distribution and levitation force changing with the train speed. And taking the middle and low speed maglev trains and rails of Changsha Maglev Express as the research object, we have adopted two solutions, and the prototypes of airsprings and levitation magnets are manufactured and tested in the train.
 Results: The test result show that the currents of the windings at the front end of the two forefront electromagnets are reduced obviously.
 Conclusion: In this paper, the medium and low speed maglev train and rail used by Changsha Maglev Express are studied, the eddy current effect is analyzed, and two solutions are proposed. The results show that the solution methods can alleviate the eddy current effects to some extent.

Electromagnetic levitated systems commonly used in the field of people transportation, tool machines frictionless bearings and conveyor systems. In the case of high speed people transport vehicles, the electromagnetic levitation offers the advantage of a very silent motion and of a reduced maintenance of the rail. Magnetic levitated trains requires the guidance force needed to keep the vehicles on the track is obtained with the levitation electromagnets, Particular shapes of the rails and to a clever placement of the electromagnets with respect to the rails helpful and effective to achieve the goal. This article gives the basic idea of the electromagnets trains and its control system mechanism

The precision machining of the rail base for high-speed Magnetically Levitated Trains (MAGLEV) is the precondition for laying the high-quality whole rail and accomplishing the integrative performance test of the train. A new method is advanced to improving the machining precision in this paper. The X and Y coordinates of the cross centers on the rail base for MAGLEV will be obtained through two raster displacement sensors which are perpendicular to each other. So the machining datum position of the rail will be determined. According to the spatial position relationship between the straight movement error of the guideway on the numerical control machine tools and the central line of the rail base for MAGLEV, error compensation will be made to improve the machining precision in the process of the numerical control machining. The mechanism design theory of the measuring system is presented in this paper. On basis of both the design theory and the software platform of LabWindows/CVI, the virtual measurement system for measuring straight movement error of the rail on the numerical control machine tool, which is used to machining the rail base for MAGLEV will be established.

The association of elevated rail structures and Maglev (magnetic levitation) trains is a promising alternative for urban transportation. Besides being cost-effective in comparison with underground solutions, the Maglev technology is a clean and low-noise mass transportation. In this paper, we propose a low-cost automatic braking system for Maglev trains. There is a myriad of sensors and positioning techniques used to improve the accuracy, precision and stability of train navigation systems, but most of them result in high implementation costs. In this paper, we develop an affordable solution, called Redundant Autonomous Safe Braking System (RASBS), for the MagLev-Cobra train, a magnetic levitation vehicle developed at the Federal University of Rio de Janeiro (UFRJ), Brazil. The proposed braking system employs GNSS (Global Navigation Satellite System) receivers at the stations and trains, which are connected via an ad-hoc wireless network. The proposed system uses a cooperative error correction algorithm to achieve sub-meter distance precision. We experimentally evaluate the performance of RASBS in the MagLev prototype located at the campus of UFRJ, Brazil. Results show that, using RASBS, the train is able to dynamically set the precise location to start the braking procedure.

Background: As high-speed rail and other transportation technologies are moving forward and gaining funding in the United States, the push for MagLev is not receiving the necessary support that would make it a viable alternative in the near future. Major changes in the approach to implementing MagLev could make a better case for it, specifically for carrying freight. One alternative that has been considered in the past is the modification of existing freight railways to support MagLev. For this to be economically feasible and practical, such a solution has to be able to support both conventional freight trains and MagLev freight. 
 Aim: The successful application of Partially Magnetically-Levitated Freight (PMLF) technology achieved by integrating superconducting MagLev technology with current railroad design and operations.
 Methods: A MagLev freight system that is envisioned to use existing rail routes must be designed to be compatible with the existing railway infrastructure. To accomplish this, every component utilized by the railroads must be examined in detail to determine if and how it could be affected by the proposed PMLF. In addition, components that will need to be modified for PMLF operation must undergo a retrofit design and testing process. The design scope must also include an examination of all existing tasks and activities that are being performed by the railroads such as track maintenance and repair. Any procedures that affect or are affected by the addition of PMLF will need to be modified. Finally, superconducting MagLev technology must be optimized and advanced for application to PMLF. 
 Opinions and Discussions: The dual use of railway lines has substantial cost advantages when compared to building new dedicated MagLev freight corridors. In fact it could make the entire proposition very appealing if proven to be technically feasible. However, there are certain limitations and concerns that would cause policy makers to reject such a proposal unless such obstacles can be shown to be temporary and non-critical. Essential rail installations such as switches are presently difficult to modify in a way that would ensure reliable functionality for both MagLev and conventional freight trains, and grade crossings pose safety risks. It is difficult to envision the tremendous leap forward of merging MagLev with existing freight rail lines when much more basic technologies such as positive train control are not even fully implemented. Consequently, it is a challenge to advance MagLev in the United States where new dedicated freight corridors are considered to be cost-prohibitive and dual use railway lines pose uncertainties that railroad companies simply do not want to solve. However, there is one more solution has not been considered that would allow a MagLev freight train to navigate on existing railway infrastructure without disrupting traditional rail utilization. This solution is a partially magnetically-levitated freight train.
 Results: After reviewing the fundamental components, systems and operations of the railways in the United States, it will be feasible and practical to introduce magnetic levitation technology to assist in moving freight on existing rail routes. PMLF trains will be able to take advantage of magnetic levitation on sections where the track has been upgraded to allow its use and much higher speed while still being able to travel on unmodified sections with the same speed as traditional trains.
 Conclusion: Modifying existing freight rail with magnetic “quasi-lift” technology is a much lower cost alternative to building an entirely new MagLev infrastructure. This alternative will provide very important benefits including enhancing safety in the rail industry. In its first phase of implementation, the proposed PMLF system will levitate a significant portion of the weight of the train but still utilize the existing steel rails for traction and guidance. The most evident advantages of this approach include reduced wear on rail and other supporting elements, and a significant reduction in friction and energy use. Locomotives, freight cars and all other components could be made lighter and travel speeds will increase dramatically due to less impact and other effects. Later phases of implementation will focus on magnetic traction and guidance. The acceptance and success of this partially levitated system will eventually lead to fully levitated freight transport technology. Sometimes it is necessary to take smaller steps to achieve the desired future.

The rails of the medium-low speed maglev system are entirely manufactured by roller milling, and eddy current in the rail can be induced when relative movement between the electromagnet and the rail manifests. The eddy current reduces the magnetic field in the air gap between the electromagnet and the rail, which, as a result, decreases the levitation force; and higher speed will cause more levitation force lost. Moreover, the eddy current produces a drag force which is opposite to the propulsion force generated by the linear inductive motor. In this paper, based on the electromagnetism, the formulae for the levitation force and the drag force of the electromagnet are deduced when the eddy current in the rail is taken account. Simulations based on the model of the maglev vehicle on the Tangshan maglev test line are also performed. The results indicates that the levitation force is significantly affected by the eddy current in the rail, and when v = 200 km/h, the levitation force of a single electromagnet is reduced by 35.6%; meanwhile, the drag force increases dramatically as the speed increases, but when the speed exceeds 100 km/h, the drag force stops increasing, and it equals 2.28% of the stationary levitation force.

Background: In order to standardize maglev transportation engineering and its operation, the research of maglev transportation technical standards becomes important. Based on the analysis of the growth of rail transit, the acceleration of maglev transportation engineering, the China’s standardization regulation and the maglev transportation technology standardization practice,
 Aim: This paper proposes the basic principles for establishing maglev transportation standard system and the framework of maglev transportation technical standard system, introducing China’s maglev transportation technology standardization mechanism, its achievements, prospects and experiences.
 Results: By the end of 2017, China had developed 12 maglev transportation technical industry and provincial standards.
 Conclusion: There are 12 maglev transportation technical industry standards and social organization standards under development.

Results of an International Survey among Transport Experts and Specialists Maglev.
 With the aim of tracking current trends in the market perspectives of magnetic levitation, or maglev technologies, the non-profit International Maglev Board conducted a primary study in the spring of 2018 among maglev specialists and transportation professionals. More than 1 000 professionals took part in the survey. Main topics of the study are questions comparing the suitability of conventional wheel-on-rail and maglev technologies according to application areas. Predicted opportunities and developments in maglev technology, acceptance issues and research needs are analyzed. The results are broken down by expertise and nationality of the participants. This short version presents selected findings of the survey in compressed form.
 Background: There is an obvious need for information on international trends in the application of Maglev transport technologies. The study attempts to grasp the global dimension of magnetic levitation developments in a structured way.
 Aim: To track current trends in magnetic levitation transport system innovation. Identify perspectives, research tasks and implementation barriers. Comparison of magnetic levitation systems with steel wheel systems. Analysis of the key topics of the debate.
 Methods: Primary study in spring 2018 among 1 058 maglev specialists and transport experts. Internet-based online survey.
 Results: The ratings vary greatly according to the expertise and origin of the respondents. In certain fields of application, wheel-rail systems remain the preferred transport technology. But in certain other fields of application, maglev technologies have become preferred over conventional steel-wheel-rail by a majority of transport professionals. This is particularly the case for high-speed maglev transport and for the new application of maglev elevators in buildings. At the same time, many respondents see a continuing need for research.
 Conclusion: Overall, there is a differentiated picture. Respondents from North and South America, Russia and Asia are on average particularly open to an implementation of certain maglev technologies.

Recently, an interest in a hybrid system combining only the merits of the conventional wheel-rail system and Maglev propulsion system is growing as an alternative to high-speed maglev train. This hybrid-type system is based on wheel-rail method, but it enables to overcome the speed limitation by adhesion because it is operated by a non-contact method using a linear motor as a propulsion system and reduce the overall construction costs by its compatibility with the conventional railway systems. Therefore, a comparative analysis on electromagnetic characteristics according to the structural combinations on the stator-mover of Linear Synchronous Motor (LSM) for Very High Speed Train (VHST) maintaining the conventional wheel-rail method is conducted, and the structure of coreless superconducting LSM suitable for 600 km/h VHST is finally proposed in this paper.