Search Results (15)

Superconducting electrodynamic suspension (EDS) maglev technology has strong potential for ultra-high-speed transportation, with advantages such as self-stability and a large suspension gap. The magneto-electric force relationship between the onboard superconducting magnet and figure-eight null-flux coils is the key to improving system performance. This article shows a novel study on the impact of the shape of null-flux coils on the superconducting EDS maglev system, which has not been systematically studied before. A 3D model of the suspension system of EDS maglev was built using the finite element method (FEM) to study the impact of the null-flux coils’ shape. The electromagnetic forces generated by the system were calculated and compared with those in the literature to validate the model. The results showed that rectangular and circular coils displayed different influences on the components of the electromagnetic force. New results and analysis from the article show that the null-flux coil shape is a promising option for system performance optimization and can provide a theoretical basis for future improvements to the high-speed EDS maglev system. Full article

To achieve global carbon-neutrality goals, magnetic levitation (maglev) technologies offer a promising pathway toward sustainable, energy-efficient transportation systems. In this study, a comprehensive methodology was developed to analyse and optimise the levitation performance of high-temperature superconducting (HTS) maglev systems. Several permanent magnet guideway (PMG) configurations were compared, and an optimised PMG Halbach array design was identified that enhances flux concentration and significantly improves levitation performance. To accurately model the electromagnetic interaction between the HTS bulk and the external magnetic field, finite element models based on the H-formulation were established in both two dimensions (2D) and three dimensions (3D). An HTS maglev demonstrator was built using YBCO bulks, and an experimental platform was constructed to measure levitation force. While the 2D model offers fast computation, it shows deviations from the measurements due to geometric simplifications, whereas the 3D model predicts levitation forces for the cylindrical bulk with much higher accuracy, with errors remaining below 10%. The strong agreement between experimental measurements and the 3D simulation across the entire force–height cycle confirms that the proposed model reliably reproduces the electromagnetic coupling and resulting levitation forces in HTS maglev systems. The paper provides a practical and systematic reference for the optimal design and experimental validation of HTS bulk-based maglev systems. Full article

The guest room and aisle of electric high-speed maglev train must be shielded from leakage magnetic flux produced by superconducting strong magnetic field. To reduce magnetic leakage, the superconducting magnetic levitation system structure is obtained by extended lagrangian optimization method. The optimized superconducting coil structure has the advantages of reducing magnetic leakage, improving magnetic field utilization, reducing the weight of the magnetic isolation plate and the weight of the maglev train, and enhancing the load-bearing capacity of the maglev train. Based on optimized superconducting coil parameters for high-speed maglev, the magnetic shielding effect at the aisle and the guest room, the magnetic flux density distribution at the magnetic shielding is calculated and analyzed through analytical calculation. The relevant conclusions indicate that the magnetic suspension structure has the advantages of reducing end coil leakage flux and the weight of the high-speed maglev train. Full article

Racetrack NbTi superconducting coil is a key component in Maglev train systems due to its excellent mechanical processing performance and lower construction cost. However, dynamic pressures during high-speed operations can influence contact pressures and cause internal filament damage, leading to critical current degradation and quench, which threaten the stable operation of the superconducting magnet. Considering that the NbTi coil has a typical hierarchical structure and comprises thousands of filaments, this study constructs an efficient multiscale framework combining the finite element method (FEM) and self-consistent clustering analysis (SCA) to study the multiscale responses of the NbTi coil. The mechanical responses of the two-scale racetrack coil under monotonic and periodic pressures are investigated, and the effects of the friction contacts between strands are also discussed. The study reveals that internal contacts significantly influence local contact pressures and microscopic stresses, and periodic loading leads to stress accumulation with cycle times. The proposed framework efficiently captures critical microscale responses and can be applied to other multiscale materials and structures. Full article

This paper proposes an A-shape hybrid levitation system combining high-temperature superconducting (HTS) maglev and permanent magnet levitation (PML) technologies to address the lateral instability of the PML system. By tilting the PM arrays and HTS bulks on both sides at a specific angle, the system’s cross-section forms an “A” shape. This configuration offers dual advantages: the A-shape PML significantly mitigates unstable lateral deflection forces while preserving levitation capacity, whereas the A-shape HTS maglev enhances guidance force. Through systematic analysis, the effects of the tilt angle and the magnetization direction of the PM arrays on levitation performance are investigated and optimized. The simulation results demonstrate that, at the lateral movement of 5 mm, for the PML system, a tilt angle of 45° reduces lateral deflection force by 94.4%, and synergistic optimization of the tilt angle of 40° and magnetization direction of 38° achieves an 84.6% reduction. The HTS maglev system enhances guidance force, with a 45.3% improvement at a 60° tilt angle and a 30° magnetization direction. This study presents a promising solution for developing a stable, high-load-capacity hybrid levitation system. Full article

This paper analyzes the viability of different solutions to passively augment the axial stiffness of a horizontal axis radial levitation passive magnetic bearing (PMB) with a previously studied topology. The zero-field cooling (ZFC) of high-temperature superconductor (HTS) bulks promotes higher magnetic impulsion and levitation forces and lower electromagnetic losses than those with field-cooling (FC) but, on the other hand, the guiding stability is much lower than those with FC. Because of stability reasons, FC was adopted in most superconducting maglev systems. The trend of this research group has been to develop a horizontal axis HTS ZFC radial levitation PMB presenting notable levitation forces with reduced electromagnetic losses, defined by a topology that creates guiding stability. Previous work has shown that optimizing the bearing geometry to maximize magnetic guidance forces might not be enough to guarantee the axial stiffness required for many applications. First, the extent to which guidance forces are augmented by increasing the number of HTS bulks in the stator is evaluated. Then, the axial stiffness augmentation by passively adding two limiting permanent magnet (PM) rings is evaluated. The results show that the axial stiffness is highly augmented by adding limiting PM rings with no significant additional investment. This change enables the use of the studied ZFC superconducting PMB in high-precision axial stability applications, such as precision gyroscopes, horizontal axis propellers, and turbines. Full article

With the global trend of carbon reduction, high-speed maglevs are going to use a large percentage of the electricity generated from renewable energy. However, the fluctuating characteristics of renewable energy can cause voltage disturbance in the traction power system, but high-speed maglevs have high requirements for power quality. This paper presents a novel scheme of a high-speed maglev power system using superconducting magnetic energy storage (SMES) and distributed renewable energy. It aims to solve the voltage sag caused by renewable energy and achieve smooth power interaction between the traction power system and maglevs. The working principle of the SMES power compensation system for topology and the control strategy were analyzed. A maglev train traction power supply model was established, and the results show that SMES effectively alleviated voltage sag, responded rapidly to the power demand during maglev acceleration and braking, and maintained voltage stability. In our case study of a 10 MW high-speed maglev traction power system, the SMES system could output/absorb power to compensate for sudden changes within 10 ms, stabilizing the DC bus voltage with fluctuations of less than 0.8%. Overall, the novel SMES power compensation system is expected to become a promising solution for high-speed maglevs to overcome the power quality issues from renewable energy. Full article

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. Full article

Maglev systems represent a cutting-edge high-speed transport technology, and turnout switches play a critical role in the creation of a highly branched network. There are two common types of turnouts for high-temperature superconducting (HTS) Maglev systems: mechanical and electromagnetic. Due to the many advantages, an electromagnetic turnout is a better choice for a Maglev system than a mechanical one. However, there is a difference in the distribution of the magnetic field over the turnout area and the permanent magnetic track, which cannot meet the safety requirements of the Maglev system. This article proposes a modernized design of an electromagnetic switch based on previously proposed optimization solutions by placing a diamagnetic screen between two electromagnetic poles of an electromagnet, thereby reducing the scattering fluxes between them. The method of diamagnetic screening and experimental methodology are described in this article. The experiment was carried out using a three-dimensional magnetic field scanner to provide results on the distribution of the magnetic field and the increase in the magnetic induction value over the electromagnet poles. Thus, this article provides valuable suggestions for improving the design of the electromagnetic turnout of HTS Maglev systems. Moreover, the proposed method can be applied to any magnetic device or electric machine with an open magnetic circuit. Full article

A maglev train is a new type of high-speed railway transportation. A high-temperature superconducting (HTS) maglev system is one of the typical representatives in the field of maglev trains. In order to research the levitation characteristics of an HTS maglev train, the force characteristics and operation performance of the train were researched. However, at present, there is still no research that simulates the real load situation of a running maglev train while analyzing the suspension frame. Regarding this issue, in this paper, the suspension frame is simulated and analyzed to simulate the real load situation of a maglev train. The results show that the suspension frame of an HTS maglev train can bear corresponding loads under different working conditions, and its strength and stiffness meet the requirements of use, safety, and reliability. Random irregularity in the permanent magnet track of an HTS maglev train route is inevitable, which will make the suspension frame produce a vibration response under different running speeds of the train. Vibration of the suspension frame of the train is inevitable. For the electromagnetic levitation (EMS) train, researchers considered monitoring the train status. However, at present, there is no suspension frame condition monitoring device for an HTS maglev train. In addition, the levitation height of the suspension frame affects the suspension performance and traction performance of the vehicle, and the vibration of the suspension frame during running affects the dynamic performance and safety of the suspension frame and the vehicle. Regarding the issue above, through a suspension frame monitoring system, the lateral and vertical vibration acceleration and levitation height of the suspension frame are monitored at different train speeds. The maximum value of vibration acceleration and the fluctuation range of levitation height are within the safe range. It is verified that the simulation analysis of the suspension frame of an HTS maglev train is correct, the suspension frame is safe, and the train can run safely. Full article

This paper employed an electrical circuit simulator to investigate an electrodynamic suspension system (EDS) for passenger rail transport applications. Focusing on a null-flux suspension system utilizing figure-eight-shaped coils (8-shaped coils), the aim was to characterize the three primary electromagnetic forces generated in an EDS and to compare the findings with existing literatures. The dynamic circuit theory (DCT) approach was utilized to model the system as an electrical circuit with lumped parameters, and mutual inductance values between the superconducting (SC) coil and the upper and lower loops of the 8-shaped coil were calculated and inputted into the simulator. The results were compared with experimental data obtained from the Yamanashi test track. The comparison demonstrated close alignment between the theoretical expectations and the obtained experimental curves, validating the accuracy of the proposed model. The study highlights the advantages of this new approach, including faster computation times and efficient implementation of modifications. Overall, this work contributes to the ongoing development and optimization of null-flux suspension Maglev systems. Full article

High-temperature superconducting (HTS) magnetic levitation (maglev) trains for designed high speed need a non-contact braking method that can produce stable and sufficient braking forces to ensure the safety of the train during emergency braking. In order to study the braking effects of permanent magnet eddy current braking (PMECB) used in HTS maglev vehicles and its effects on the levitation performance of HTS maglev vehicles, an equivalent two-dimensional simulation model of PMECB for a HTS maglev test vehicle under different working air gaps of 5 mm, 10 mm, 15 mm and 20 mm was established in Maxwell software. Then, a 6 degree of freedom dynamic model of the vehicle was established in Universal Mechanism software. In the dynamic simulation, the normal force of PMECB was not considered, and only the detent force of PMECB was taken as the excitation of the vehicle. The simulation results show that PMECBs can reduce the vehicle to relatively low speed in a few seconds. During the operation of PMECBs, the levitation height and levitation force of the maglev Dewar will be affected, and maximum variations in levitation heights and levitation forces occur on the Dewars at both ends of the vehicle. These help us to understand the braking and levitation performance of HTS maglev vehicles under the action of PMECBs and enrich the design idea of braking and levitation systems of HTS maglev vehicles equipped with PMECBs. Full article

The null-flux electro-dynamic suspension (EDS) system is a feasible high-speed maglev system with speeds of above 600 km/h. Owing to their greater current-carrying capacity, superconducting magnets can provide a super-magnetomotive force that is required for the null-flux EDS system, which cannot be provided by electromagnets and permanent magnets. Relatively mature high-speed maglev technology currently exists using low-temperature superconducting (LTS) magnets as the core, which works in the liquid helium temperature region (T ⩽ 4.2 K). Second-generation (2G) high-temperature superconducting (HTS) magnets wound by REBa${}_2$Cu${}_3$O${}_{7-\delta }$ (REBCO, RE = rare earth) tapes work above the 20 K region and do not rely on liquid helium, which is rare on Earth. In this study, the HTS non-insulation closed-loop coils module was designed for an EDS system and excited with a persistent current switch (PCS). The HTS coils module can work in the persistent current mode and exhibit premier thermal quenching self-protection. In addition, a full-size double-pancake (DP) module was designed and manufactured in this study, and it was tested in a liquid nitrogen (LN2) environment. The critical current of the DP module was approximately 54 A, and it could work in the persistent current mode with an average decay rate measured over 12 h of 0.58%/day. Full article

On the basis of a generalized interdisciplinary method that consists of a modification of Hamilton–Ostrogradski principle by expanding the Lagrange function with two components that address the functions of dissipation energy and the energy of external conservative forces, a mathematical model is presented of an electromechanical system that consists of the force section of a magneto-levitation non-contact maglev suspension in a prototype traction vehicle. The assumption that magnetic potential hole, generated naturally by means of cryogenic equipment, is present in the levitation suspension, serving to develop the model system. Contrary to other types of magnetic cushion train suspensions, for instance, maglev–Shanghai or Japan–maglev, this suspension does not need a complicated control system, and levitation is possible starting from zero train velocity. As high-temperature superconductivity can be generated, the analysis of levitation systems, including the effect of magnetic potential holes, has become topical. On the basis of the model of a prototype maglev train, dynamic processes are analyzed in the levitation system, including the effect of the magnetic potential hole. A system of ordinary differential equations of the dynamic state is presented in the normal Cauchy form, which allows for their direct integration by both explicit and implicit numerical methods. Here, the results of the computer simulations are shown as figures, which are analyzed. Full article

Sub-sonic linear synchronous motors (LSMs) with high-temperature superconducting (HTS) magnets, which aim to accelerate to a velocity of 1200 km/h in the near-vacuum tubes of 0.001 atm for the Hyperloop, are newly introduced in this paper. By the virtue of the combination of LSMs and electrodynamic suspensions (EDSs) with HTS magnets, a large air-gap of 24 cm, low magnetic resistance forces of below 2 kN, and the efficient as well as practical design of propulsion power supply systems of around 10 MVA could be guaranteed at a sub-sonic velocity. The characteristics of the proposed LSMs with HTS magnets, in addition, are widely analyzed with theories and simulation results. Optimal design methods for LSMs and inverters, which account for more than half of the total construction cost, are introduced with design guidelines and examples for the commercialization version of the Hyperloop. At the end of the paper, in order to verify the proposed design models of the sub-sonic LSMs, two different test-beds—i.e., 6 m long static and 20 m long dynamic propulsion test-beds—are fabricated, and it is found that the experimental results are well matched with proposed design models as well as simulation results; therefore, the design methods constitute guidelines for the design of sub-sonic LSMs for the Hyperloop. Full article