Maglev Transportation System Research Articles

Damping characteristics of High-Temperature superconducting pinning maglev levitation system

High-temperature superconducting (HTS) pinning maglev has achieved rapid development in recent decades. The levitation system of the HTS pinning maglev is mainly composed of Dewar with built-in HTS bulks and permanent magnet guideway (PMG). For a maglev transportation system, damping is important for vibration attenuation, and the inherent damping characteristics of the HTS pinning maglev system have not been evaluated clearly. In this paper, the damping characteristics of the HTS pinning maglev system are analyzed through experiments and simulations. Experiments are conducted to measure the dynamic responses of the system under free and forced vibrations. The logarithmic envelope method is used to evaluate the system damping under free vibration. The cross-correlation function is utilized to obtain the phase difference between the system vibration signal and excitation signal, and then calculate the system damping under forced vibration conditions. In addition, a two-dimensional finite element model including HTS bulks, PMG, and Dewar conductive shells is established to evaluate the damping force generated by each component during system vibrations. The additional eddy current damping of the conductive Dewar shell is considered and analyzed. Finally, from the perspective of system damping and thermal stability of HTS bulks, suggestions for selecting Dewar shell materials are proposed.

Optimal Control for a Superconducting Hybrid MagLev Transport System with Multirate Multisensors in a Smart Factory.

Recently, magnetic levitation systems have been applied and studied in various industrial fields. In particular, in-tracktype magnetic levitation conveyor systems are actively studied since they can effectively minimize electromagnetic effects in processes that require a highly clean environment. In this type of system, diverse and multiple sensors are structurally required so that the control performance of an integrated system is primarily governed by the slowest measuring sensor. This paper proposes a multisensor fusion compensator to integrate the outputs obtained from various sensors into one output with the single fastest time rate. Since the state of the system is estimated at a fast time rate, the optimal controller also guarantees fast performance and stability. The computation of electromagnetic fields and the control performance of the considered superconducting hybrid system were analyzed using a computer simulation based on finite element methods.

Linear generator for power supply to on-board consumers of high-speed magnetically levitated carriages

Background: Maglev transport is a promising mode of transport that can provide passenger and freight transportation at speeds of up to 400-500 km/h, and in the longer term – up to 1000 km/h. Active research in this area is being conducted in China, Japan, and the USA. Currently, in China and Japan, speeds of 450-500 km/h have been achieved for commercial transportation, and promising programs have been adopted for the construction of high-speed maglev tracks and the creation of rolling stock. At such speeds, one of the pressing problems is the problem of contactless energy transfer for on-board consumers located on the carriage, because it is very difficult to ensure reliable contact current collection at speeds of 450-500 km/h and above.
 Aim: development of the design, calculation and analysis of the characteristics of a linear generator of electrical energy for contactless power transfer to the moving crew of high-speed magnetically levitated transport.
 Materials and methods: to calculate the external magnetic field of the linear generator inductor and the EMF induced in the receiving coil of the crew, methods of electromagnetic field theory and electrical circuit theory were used; calculation algorithms are implemented in the Visual Basic for Applications software environment.
 Results: a design was proposed and the calculation of the external magnetic field of an inductor with transposition of conductors was performed; to increase the EMF induced in the receiving coil of the crew, it is proposed to give the receiving coil a double 8-shape; the most rational inter-circuit distance of the linear generator inductor has been established; the nature of the change in the magnetic flux penetrating the receiving coil when the vehicle moves, and the magnitude of the emf induced in the receiving coil are determined.
 Conclusion: the results can be used in the development of rolling stock for promising high-speed maglev transport systems.

On the suitability of medium speed maglev transport systems: an analysis of perceptions in the transportation sector

Background: Medium speed maglev transport systems are considered a disruptive innovation. This complicates potential access to the transport market, which is dominated by conventional, traditional transport systems. Can maglev systems compete with them?
 Aim: Aimed specifically at transport professionals, the survey analyses current [2023] perceptions of maglev systems for passenger and freight transport. Are medium speed maglev systems suitable for the future of transport from the perspective of transport experts?
 Methods: International web survey of five hundred professionals in the transport sector. The focus is on application and suitability. It is not a technical comparison of systems.
 Results: Medium-speed maglev systems are considered to be competitive, and in some cases superior, to established transport systems in the same speed range. However, most international experts see the suitability of maglev systems primarily for specific applications, such as passenger transport between airports and city centers, or as a freight transport system for special logistics tasks.
 Conclusion: An innovation of maglev systems in well-defined applications seems reasonable and promising from an expert's point of view.

Numerical Simulations of Space Charge Waves Amplification Using Negative Differential Conductance in Strained Si/SiGe at 4.2 K

This paper introduces a two-dimensional (2D) numerical simulation of the amplification of space charge waves using negative differential conductance in a typical MOS silicon–germanium (SiGe)-based field-effect transistors (FET) and complementary metal oxide semiconductor (CMOS) technology at 4.2 K. The hydrodynamic model of electron transport was applied to describe the amplification of space charge waves in this nonlinear medium (i.e., the negative differential conductance). This phenomenon shows up in GaAs thin films at room temperature. However, this can be also observed in a strained Si/SiGe heterostructure at very low temperatures (T < 77 K) and at high electric fields (E > 10 KV/cm). The results show the amplification and non-linear interaction of space charge waves in a strained Si/SiGe heterostructure occurs for frequencies up to approximately 60 GHz at T = 1.3 K, 47 GHz at T = 4.2 K, and 40 GHz at T = 77 K. The variation of concentration and electric field in the Z and Y directions are calculated at 4.2 K. The electric field in the Z direction is greater than in the Y direction. This is due to the fact that this is the direction of electron motion. In addition to deep space applications, these types of devices have potential uses in terrestrial applications which include magnetic levitation transportation systems, medical diagnostics, cryogenic instrumentation, and superconducting magnetic energy storage systems.

Investigation of the Transverse Flux Linear Synchronous Motor Integrated With Propulsion, Levitation and Guidance for the Maglev Train

Conventional electromagnetic suspension (EMS) high-speed trains adopt linear synchronous motors (LSMs) and electromagnets together to provide propulsion, levitation and guidance (PLG) forces. In this paper, a new transverse flux linear synchronous motor (TFLSM) is presented for high-speed maglev trains, which can concurrently provide PLG forces. First, the topology and operating principle of TFLSMs are introduced. Second, the electromagnetic characteristics in the TFLSMs and conventional LSMs applied in high-speed maglev trains under the same dimensional conditions are compared and analyzed using the three-dimensional (3-D) finite element method (FEM). A quantitative comparison of the two motors is carried out to show the feasibility of TFLSMs in maglev transportation system applications. Third, the variations of electromagnetic forces in TFLSM with different mechanical parameters and input currents are calculated and analyzed. Finally, the test platform of the prototype TFLSM is built and experiments are conducted to validate the simulation results. Compared with the conventional LSMs, the levitation force generated by TFLSM is increased by 55% and the propulsion force is increased by 21%.

Design of an Electromagnetic Turnout Scheme for a Two-Line PMG of HTS Maglev Systems

The Maglev transport system is a new promising high-speed system of the future, which includes many different applications that ensure its fast and reliable operation. For the possibility of transferring rolling stock from one track to another, a turnout switch is needed. It has been proved that the electromagnetic turnout switch is one of the best choices for the Maglev switch systems because there are no moving parts. Some schemes and designs of an electromagnetic turnout switch have already been proposed, but still no schemes for entering into a real two-line permanent magnet guideway (PMG) of the Maglev system. In this article, the whole electromagnetic turnout switch for a two-line PMG is considered, electromagnetic turnout schemes have been developed for installation in a real full-scale two-line PMG of the Maglev system, and the main elements of an electromagnetic turnout switch are shown. The formulas for calculation of the total length of an electromagnetic turnout switch and the radius of the transfer curve were presented. Moreover, in this paper, the displacement of the magnetic axis of the left and right rails relative to the theoretical axis due to the arrangement of magnets in a way of checkerboard was studied.

Permanent Magnet Electrodynamic Suspensions Applied to MAGLEV Transportation Systems: A Review

This article reviews permanent magnet electrodynamic suspensions (PM-EDSs) used in ground transportation systems, such as Magnetic Levitation (MAGLEV) trains. The different suspension topologies are first presented, considering separately their two main components, namely the track and the magnetic field source. Beyond that, a phenomenological explanation of the evolution with the speed of the drag and levitation forces is provided, depending on the track topology. The models aimed at predicting the behavior and performance of the suspension are then detailed, classifying them according to whether they are global or local. Finally, the main experimental setups developed to validate PM-EDSs are described.

Physical Structure Expression for Dense Point Clouds of Magnetic Levitation Image Data.

The research and development of an intelligent magnetic levitation transportation system has become an important research branch of the current intelligent transportation system (ITS), which can provide technical support for state-of-the-art fields such as intelligent magnetic levitation digital twin. First, we applied unmanned aerial vehicle oblique photography technology to acquire the magnetic levitation track image data and preprocessed them. Then, we extracted the image features and matched them based on the incremental structure from motion (SFM) algorithm, recovered the camera pose parameters of the image data and the 3D scene structure information of key points, and optimized the bundle adjustment to output 3D magnetic levitation sparse point clouds. Then, we applied multiview stereo (MVS) vision technology to estimate the depth map and normal map information. Finally, we extracted the output of the dense point clouds that can precisely express the physical structure of the magnetic levitation track, such as turnout, turning, linear structures, etc. By comparing the dense point clouds model with the traditional building information model, experiments verified that the magnetic levitation image 3D reconstruction system based on the incremental SFM and MVS algorithm has strong robustness and accuracy and can express a variety of physical structures of magnetic levitation track with high accuracy.

CONCEPTUAL FUNDAMENTALS OF FREIGHT MAGNETOLEVITATION TRANSPORT SYSTEM CONSTRUCTION

An analysis of the transport systems current state in Ukraine has shown that the main problem in this area is the lack of transport infrastructure capacity, due to low route speeds for most transport modes and low levels of traffic organization and management. The level of rail container transport, the most common and perspective type of freight transportation is also low compared to European countries. Therefore, the main idea of the article is to justify the need for the introduction of fundamentally new transport technologies that will help reduce or eliminate the problems of freight transport, and so the article is relevance. The possibility of using magnetic technologies that exclude contact of a vehicle with a road structure, for freight transportation is investigated. The authors consider the main structural elements, functions and possible options of the magnetic levitation transport system of freight transport. The practical value of the work is that the use of magnetic levitation container platforms will significantly increase the intensity and speed of the conveyor sending of each container with a decrease in energy consumption, which will significantly affect the improvement of cargo logistics. The main results of the work: the conceptual bases of construction of unmanned magnetic levitation vehicles and the main systems of their infrastructure are formulated, it is shown that the implementation of the function of drone for the vehicle is possible only if permanent levitation in all sections of the freight transportation will be provided.

Field experimental tests and analyses of suspension frame vibration of low-medium speed maglev train

Pushed by social demands, China has continuously developed its low-medium speed maglev transportation systems in recent decades. However, with the increase of the running mileage of the train, high frequency vibration of suspension frame gradually appears. In this paper, a method to analyze the high frequency vibration of suspension frame by detecting the current of traction motor is proposed. Field measurements of suspension frame vibration and traction motor current of low-medium maglev train were conducted on a maglev line that has been commercially put into operation. The test results show that the speed of the measured maglev train was closely correlated with vibration accelerations of the suspension frame in three directions, but as the speed increased, the influence it imposed on the suspension frame vibration waned. The dominant frequency of traction motor resultant current was consistent with the dominant frequency of the suspension frame vibration acceleration. The switching frequency of traction inverter was the main cause of high frequency vibration of suspension frame.

Research on the Mechanism and Control Characteristics of Vehicle-Track Beam Coupling Vibration for Medium-Speed Maglev Vehicle

In the maglev transportation system, the track beam may vibrate under the dynamic levitation force of the maglev vehicle due to its own elastic characteristics, which may cause the vehicle to vibrate. At present, the general method of suppressing vibration is to improve the stiffness, density, damping of the bridge, and the accuracy of track installation, which will result in higher construction costs. In this article, the simulation analysis of the vehicle-rail coupling vibration is carried out from the perspective of suspension control characteristics. Through theoretical derivation, a mathematical model is established, and the mechanism of the vehicle-bridge coupling system vibration is analyzed through simulation. The internal influence of the main parameters of the controller on the system vibration is discussed. Theoretical analysis and simulation research show that the mismatch between the structural parameters of the track beam and the controller parameters will cause coupled vibration, while adjusting the parameters to match the track beam structure can suppress vibration to a certain extent. Taking the 25-m simply supported beam of Changsha Maglev Express as the research object, the vehicle-bridge coupled vibration characteristics test under 75–140-km/h operating speed is carried out, and the dynamic response of the vehicle and the bridge frame is obtained. Dynamic experiments show that proper controller parameters can maintain a stable suspension of the vehicle. This research provides theoretical and experimental references for vehicle-track coupled vibration suppression and maglev transportation system optimization.

Dynamic Performance of Medium Speed Maglev Train Running Over Girders: Field Test and Numerical Simulation

With the ongoing development and deployment of medium-low speed maglev vehicles in China, it has become common to increase operational speeds from 100[Formula: see text]km/h up to 140[Formula: see text]km/h or even 160[Formula: see text]km/h, necessitating further studies and simulation models to understand the implications of these changes. This paper analyzes medium-speed maglev vehicle-track-girder coupling dynamic performance at a speed of 160[Formula: see text]km/h. First, a field dynamics experiment is carried out on the Changsha Maglev Express with a running speed of 80–140[Formula: see text]km/h. Then we introduce the distributed coupling simulation platform for maglev transportation system (MTS-DCSP) and the vehicle-track-girder coupling model, taking into account the complex vehicle structure, the guideway structure, and the Proportion Integral Differential (PID) levitation control system. Together, this platform and model can conduct a simulation of the complete process at scale and at all degrees of freedom to obtain accurate results. Our analysis of the results gives an accurate portrayal of the coupling dynamics properties and validates the coupling model. The results from the field experiments together with the coupling simulation demonstrate that the medium-speed maglev train can operate safely and stably within the range of 140–160[Formula: see text]km/h. While at 140[Formula: see text]km/h, however, the Sperling ride quality index (RQI) is about 2.5, which is within the Excellent grade range, at a speed of 160[Formula: see text]km/h, the Sperling ride quality index can increase to as high as 2.74, which is a grade of Good. Therefore, it is necessary to optimize the parameters of the secondary suspension system to improve the ride comfort of the maglev vehicle at 160[Formula: see text]km/h.

Russian Maglev in integrated transport system

Background: Depending on the observed economic and geopolitical situation, before moving to a higher level, there were dependencies on excessive dependence between its regions in conditions of limited resources. A prerequisite for achieving national stability and security is the development of an integrated transport system of the country based on deep cooperation of all modes of transport, which makes it possible to effectively meet the demand for transportation both in technological and economic terms. At the same time, scientific and technological progress should not lead to the breakdown of connections in the transport system, it has a progressive nature, the possibility of interaction between the interaction of various modes of transport - rail, water, automobile, aviation, and prospective, in particular, maglev.
 Aim: to consider the possibility of including maglev transport, made according to Russian technology, into the integrated transport system of Russia as a priority mode of transport, to determine the principles of an integrated transport system and to rank the types of transport according to the degree of their compliance with national interests.
 Materials and Methods: the methodology of the study is based on the analysis of methods for evaluating the effectiveness of modes of transport, as well as the analysis of the technical and technological features of modes of transport. The information base of the study is based on the statistical information of the state statistics bodies of the Russian Federation, reports of companies participating in the transport industry, as well as data from open sources.
 Results: as a result of the research, substantiated the most complete compliance of the Russian Maglev transport system with national interests, the interests of business and society, identified promising niches for the use of the technology.
 Conclusion: the study confirms that the Russian Maglev technology should form the basis of the integrated transport system of Russia, which will ensure the country's transport security and high economic efficiency of cargo transportation.

Dynamic guidance performance of GdBaCuO and YBaCuO bulk single grain superconductors under a varying external magnetic field

High temperature superconducting (HTS) maglev technology has attracted considerable attention from researchers around the world. It provides a new direction of development for urban rail and high-speed rail transit due to its considerable advantages of frictionless transportation, low noise, and environmental protection. HTS bulk materials are able to provide a significant performance advantage to maglev technology and are a key component to achieving both levitation and vehicle guidance. HTS bulk samples with enhanced flux pinning characteristics can enable improved curve negotiating ability and lateral stability for the maglev vehicle. This paper reports the results of experiments on the dynamic guidance force of single grain Y–Ba–Cu–O (YBCO) and Gd–Ba–Cu–O (GdBCO) bulk HTS single grains in order to explore their potential for enhanced maglev guidance performance. A customized HTS maglev dynamic measurement system (SCML-03) with a rotating, circular permanent magnet guideway (PMG) was employed to simulate the dynamic operation of the HTS vehicle above the PMG at different translational speeds. It was observed from the experimental results that the GdBCO bulk superconductor is more able to resist the attenuation of the dynamic guidance force compared to YBCO under the same operational conditions. In addition, the GdBCO bulk single grain is more able to return to the original equilibrium position following exposure to an external displacement. It is concluded that the GdBCO bulk single grain offers greater potential than YBCO for practical application in HTS maglev given its enhanced guidance performance. The results of these tests provide an important benchmark for the future design of HTS maglev transportation systems.

Displacement-Constrained Neural Network Control of Maglev Trains Based on a Multi-Mass-Point Model

To address the safety displacement-constrained control problem of maglev trains during operation, this study applied the radial-based neural network control displacement-constrained method to maglev trains based on the multi-mass-point model, and strictly limited the output of maglev train displacement and speed values to keep the overshoot within a given range. Firstly, the dynamics and kinematics of the maglev train were modeled from the perspective of multi-mass modeling. Secondly, the basic structure of the radial-based neural network was determined according to the displacement-limited constraints of the maglev train during operation, and the stability was proven by applying the control rate and output-limited priming according to the limitations. Finally, based on the displacement-limited operation control of maglev trains, the system of the radial-based neural network was simulated. The simulation results show that this method can make the displacement and velocity signals of the maglev train converge to the command signals, the target convergence position is reached rapidly, and the deviation can be kept within a stable range so that the displacement and velocity signals of the maglev train can be limited to the desired safety constraints, which can guarantee the stability and safety of the maglev transportation system in the operation process.

Experimental investigation on vibration characteristics of the medium–low-speed maglev vehicle–turnout coupled system

The steel turnout is one of the key components in the medium–low-speed maglev line system. However, the vehicle under active control is prone to vehicle–turnout coupled vibration, and thus, it is necessary to identify the vibration characteristics of this coupled system through field tests. To this end, dynamic performance tests were conducted on a vehicle–turnout coupled system in a medium–low-speed maglev test line. Firstly, the dynamic response data of the coupled system under various operating conditions were obtained. Then, the natural vibration characteristics of the turnout were analysed using the free attenuation method and the finite element method, indicating a good agreement between the simulation results and the measured results; the acceleration response characteristics of the coupled system were analysed in detail, and the ride quality of the vehicle was assessed by Sperling index. Finally, the frequency distribution characteristics of the coupled system were discussed. All these test results could provide references for model validation and optimized design of medium–low-speed maglev transport systems.

Electrotechnical complex of maglev rolling stock

Background: The development of work in the field of creating cargo maglev transport systems is associated with the development and study of the electro technical complex of the rolling stock for the operating range with long stretches in poorly developed territories.
 Aim: The aim of the work is to substantiate the structure and parameters of the components of the electro technical complex of the rolling stock, to study the operating modes.
 Methods: The main research methods are functional structural analysis and synthesis, computer modeling, computational studies, analysis of research results.
 Results: As a result of the research, the factors that determine the appearance of the electrotechnical complex of the rolling stock have been identified. The basic requirements for the electrical complex are formulated. The structure was developed and the parameters of the components of the electrical complex for the transport platform with magnetic levitation were determined. A high-speed flat car model 13-6990 for the transportation of containers was chosen as the closest railway analogue. A computer model of a combined traction-levitation system based on a linear reluctance inductor motor has been developed. The results of computational studies, confirming the physical feasibility of the electrical complex of the rolling stock with linear reluctance inductor motors, are presented.
 Conclusion: The practical significance lies in the fact that the proposed concept of constructing an electro technical complex of rolling stock provides for the creation of a maglev transport system with a low-cost infrastructure.

String superstructures for maglev transport

Aim: Justification of the technical feasibility of using string spans made of polymer composite materials for maglev transport systems.
 Methods: Computational and theoretical methods of research.
 Results: It is shown that by stretching the string and applying special design solutions, it is possible to create a close to" ideal" profile of the track structure for the maglev ovement. At the same time, it is preferable to use polymer composites as the string material, which allow for less sagging than metal ones at the same level of string tension.
 Conclusion: The alternative to traditional reinforced concrete or metal structures of string composite superstructures is justified.

A RESEARCH REVIEW ON MAGNETIC LEVITATION TRAINS

This paper involves the design hardware, technology, application and future uses of “Magnetic levitation trains.” The maglev transportation system is more stable, faster, economic, efficient. Maglev systems are currently in use for applications such as bearings, high- speed trains, and manufacturing. Maglev is a method of propulsion that uses magnetic levitation to propel vehicles with magnets rather than with wheels, axles and bearings. With maglev, a vehicle is levitated a short distance away from a guide way using magnets to create both lift and thrust (levitation would not exceed above 10 centimeters). In future these High-speed maglev trains would give a huge competition to the aviation industry.