In this paper, the dynamic response characteristics of the suspension vehicle system caused by the quenching of superconducting magnets are investigated. Based on the established full-coupled magnetic/rail calculation model of the electric suspension system in the closed-loop operation mode of superconducting magnets, the superconducting magnet quenching at different positions is numerically simulated and analyzed, considering the superposition effect of dynamic electromagnetic force fluctuations and track irregularities. In addition, the moving interval algorithm is adopted to solve the long track line in the dynamic model, which significantly improves the computational efficiency of the model. The results show that the quenching of non-articulated frame magnets has a greater impact on the safety of the suspension vehicle than that of articulated frame magnets. The quenching of the middle magnets has a greater impact on the lateral and vertical dynamic response changes of the suspension vehicle system. The position of the quenched magnet has a significant impact on the safety and dynamic response characteristics of the suspension vehicle.

Energy management in hybrid fuel cell ship systems faces the dual challenges of optimizing hydrogen consumption and ensuring power quality. This study proposes an Improved Weighted Antlion Optimization (IW-ALO) algorithm for multi-objective problems. The method incorporates a dynamic weight adjustment mechanism and an elite-guided strategy, which significantly enhance global search capability and convergence performance. By integrating IW-ALO with the Equivalent Consumption Minimization Strategy (ECMS), an improved weighted ECMS (IW-ECMS) is developed, enabling real-time optimization of the equivalence factor and ensuring efficient energy sharing between the fuel cell and the lithium-ion battery. To validate the proposed strategy, a system simulation model is established in Matlab/Simulink 2017b. Compared with the rule-based state machine control and optimization-based ECMS methods over a representative 300 s ferry operating cycle, the IW-ECMS achieves a hydrogen consumption reduction of 43.4% and 42.6%, respectively, corresponding to a minimum total usage of 166.6 g under the specified load profile, while maintaining real-time system responsiveness. These reductions reflect the scenario tested, characterized by frequent load variations. Nonetheless, the results highlight the potential of IW-ECMS to enhance the economic performance of ship power systems and offer a novel approach for multi-objective cooperative optimization in complex energy systems.

The quench condition as an extreme operating condition is rarely considered in the mathematical model, but is of great significance to preventing train accidents in advance. In this paper, a closed-loop operational model for the superconducting magnet aboard the vehicle was developed, and comprehensive equivalent circuit equations for the magnetic/rail system were derived, taking into account the magnetic levitation system. The study focused on the current flowing through the superconducting coil and the variations in dynamic magnetic force within the magnetic levitation system during the loss-of-superconductivity process. Secondly, multi-body dynamic mathematical model with 55-degree of freedom (DOF) is established to simulate a more realistic operating condition of the train, and its reliability is validated by SIMPACK/MATLAB co-simulation. Finally, the electro-magnetic interactions with magnet quenched are input into the dynamic model as external disturbances to investigate the vehicle dynamic characteristics of superconducting EDS train. The results indicate that, the quench suspension frame will move laterally and vertically towards the quench side when the SCM is quenched. The lateral displacement speed of the quench magnet is large, and the suspension vehicle will first touch the side wall of the track to cause suspension instability.

To improve the ride comfort of an electrodynamic suspension (EDS) train on the Yamanashi test line, an optimization of the air-cored superconducting linear synchronous motor (SLSM) is conducted to reduce the thrust ripple, considering the geometry of general racetrack coils. First, an analytical model based on general racetrack coils is given to calculate the thrust of the SLSM, which takes the elliptic effect edges into consideration. Second, combining the analytical model with the response surface method, a surrogate model is yielded to express the thrust with six variables. Third, the multiobjective optimization of the SLSM is carried out, taking the surrogate model as the fitness function of the genetic optimization algorithm. Fourth, the thrust ripple of the optimized SLSM is evaluated by finite-element models and compared with that of the original, considering the variable postures of the secondary resulting from the multi-degree-of-freedom motions of the EDS train. Finally, the optimization is verified by the measured thrust. Consequently, the thrust ripple of the SLSM is reduced by 49% with the invariant thrust and material consumption. In this work, an optimization of the SLSM is provided to enhance the comfort of the Yamanashi test line and the future EDS system.

Complex vehicle-track coupling relationship with respect to time and space, leads to underlying challenge for the reliable evaluation of vehicle dynamic characteristics in superconducting electrodynamic suspension (EDS) train, especially for the track fitted with propulsion, levitation and guidance (PLG) coils. To calculate the electromagnetic interactions considering different cross-connections, an analytical method is deduced and synthetically verified via finite element simulation and experiment data in this paper. Secondly, multi-body dynamic mathematical model with 66-degree of freedom (DOF) is established to simulate a more realistic operating condition of the train, and its reliability is validated by Universal Mechanism (UM). Afterward, resorting to back-propagation (BP) neural networks algorithm, the mapping relationship is predicted among the spatial attitude of magnetic unit and electromagnetic interactions, to improve the efficiency of variable stiffness dynamic model. Finally, the electromagnetic interactions and track irregularities are input into the dynamic model as external disturbances to investigate the vehicle dynamic characteristics of diverse cross-connections for PLG coils. The results indicate that, the decrease of cross-connection cables can shorten the construction cost of track, but it comes at the expense of lateral stability for head and tail cars. Hence, it is imperative to carefully consider the trade-off between track cost and train stability during the design and layout process.

超导电动磁悬浮列车是下一代高速轨道交通的主要发展方向之一,而动力学问题是影响其应用性能的一个重要方面.为了提高超导电动磁悬浮列车的运行安全性和乘坐舒适性,提出基于天棚-地棚混合阻尼的超导电动磁悬浮列车半主动减振控制方法.基于动态电路理论计算了磁轨间的电磁力,利用SIMPACK和Simulink平台进行电磁力计算、动力学和控制方法的联合仿真,确定控制方法的最优最大阻尼系数和比例系数,对比分析被动悬挂与混合阻尼半主动悬挂的车体和悬浮架的振动控制效果.研究结果表明,被动悬挂下,超导电动磁悬浮列车的横向动力学性能劣于垂向;垂向混合阻尼比例系数为1时,铰接式悬浮架和非铰接悬浮架的横向混合阻尼比例系数分别为1和0.4时减振效果最佳.相比于被动悬挂,混合阻尼半主动悬挂下头车垂向和横向Sperling平稳性指标分别降低了 20.9％和8.8％,横向平稳性等级由良好升为优级;中间车垂向和横向平稳性指标分别降低了 7.4％和17.3％.铰接式悬浮架和非铰接悬浮架的横向加速度方均根值分别降低了 12.5％和15.9％.从频域上看,车体和悬浮架小于5 Hz的低频振动得到有效抑制.以上研究结果验证了混合阻尼半主动控制能有效提高超导电动磁悬浮列车的运行安全性和乘坐舒适性.

In the previous studies of superconducting EDS train, the magneto-electric coupling between superconducting magnets (SCMs) and null-flux coils (NFCs), was equivalent to a vibration system with constant stiffness. This premise has decoupled the magnetic/track interaction and is not able to study the dynamics issues in an accurate and comprehensive level. Therefore, the vehicle-track coupled dynamics model of superconducting EDS train, with magneto-electric-force coupling fully considered, was established to explore the vehicle-track interaction relationship in this paper. A mathematical model based on Newton's laws and 3-D dynamic co-simulation model were built respectively by Simulink and MATLAB-SIMPACK to compare the operating performances with the time/frequency domain. Meanwhile, the dynamic electromagnetic forces were calculated by dynamic circuit theory rather than merely assuming the constant stiffness. The dynamic responses of suspension vehicle show that, the vibration of carbody and frame are mainly concentrated about 1 Hz and 5 Hz respectively. The use of equivalent model in the previous studies has overestimated the negotiation capacity of superconducting EDS train. Furthermore, the vertical vibration accelerations of frame in the coupled model are relatively larger, whereas the lateral vibration is comparatively smaller. Therefore, the electromagnetic calculation of superconducting EDS train with constant stiffness overestimates/underestimates the dynamic performances.

为了提高超导电动磁悬浮列车动力学性能、改善列车运行平稳性和乘坐舒适性,提出基于可调因子的模糊-改进型天棚阻尼半主动复合控制方法.基于牛顿-欧拉方程建立车辆4自由度横向动力学模型,并通过逆傅里叶变换得到轨道随机不平顺激励;采用改进型天棚阻尼控制策略,结合模糊控制和可调因子方法,提出模糊-改进型天棚阻尼半主动复合控制策略和基于可调因子的模糊-改进型天棚阻尼半主动复合控制策略,探究列车在不同控制策略下的动力学性能.研究结果表明,模糊-改进型天棚阻尼策略和可调因子模糊-改进型天棚阻尼控制策略均可改善车辆的运行平稳性,且后者控制效果明显更优.

The superconducting electrodynamic suspension (EDS) train, which has reached a manned speed of 603 km/h in 2015, and is therefore regarded as one of the most attractive technologies for the higher speed train. In the superconducting EDS train, the discrete layout of ground null-flux coils causes the additional electromagnetic ripples towards the bogies, making the vibration control more essential to ensure the running performance. In this work, a fourteen-degree-of-freedom dynamics model of superconducting EDS train, was established to explore the effective strategy for vibration reduction. This model uses the time domain wave of track irregularity spectrum as the input of vehicle system. MATLAB/Simulink and "Zhai’s method" are both adopted to solve the vehicle dynamic model and validate the model. Using these models, the effectiveness of the proportional force and maximum force for the primary suspension was examined. The results show that the maximum force strategy has advantage over the proportional force strategy in terms of energy consumption and vibration sensitiveness. However, the electromagnetic damping control can only suppress the vibration of bogie. To achieve an overall vibration control, the "ON-OFF" sky-hook damping was further introduced to the secondary suspension to suppress the vibration of car body. We find that, the control effect is preferable with the damping value being between 5 kN·s/m and 10 kN·s/m. Therefore, the cooperative control, considering both the primary and secondary suspensions, is necessary to meet the Urban Tracked Aircushion Vehicle Standard and provide theoretical supports for the suspension design of superconducting EDS train.

为了提高超导电动磁悬浮列车的乘坐舒适性,建立由三辆车体与四台转向架铰接式组成的14自由度超导电动磁悬浮列车垂向-俯仰动力学模型,以轨道随机不平顺时间序列作为激励,通过研究车体垂向速度和垂向加速度的耦合作用规律,提出改进天棚阻尼半主动控制方法.通过建立仿真模型,对比分析天棚阻尼和改进天棚阻尼两种半主动控制方法应用于超导电动磁悬浮车辆次级悬挂的减振效果.结果表明,在改进天棚阻尼控制作用下,编组车辆中间车体质心处的垂向加速度和俯仰加速度的均方根值相比被动控制分别降低19.77％和17.34％;在获得相同减振效果的前提下,相较于天棚阻尼半主动控制方法,改进天棚阻尼控制半主动方法作用下输出控制力的峰值减小12.8％,因此改进天棚阻尼控制方法控制效果更佳,减振效率更高,更适用于车辆振动的控制.

A numerical model has been developed to investigate the dynamic characteristics of the Superconducting electrodynamic suspension (EDS) system. Modeling of the guideway with the surface irregularity and the Maglev vehicle are described. Numerical simulations were performed in Simulink to solve the coupled problem. A 3-D model of the electromagnetic system of the superconducting EDS train is established, and the computed real electromagnetic forces are coupled with the maglev train. The EDS train was simulated by using the SIMPACK multi-body dynamic program. The simulation was carried out by using two body models of rigid and flexible bodies. In order to use the modal information to construct the flexible car body, the finite element method and the ABAQUS software were used to construct it together with equivalent elements. The final framework is constructed in MATLAB/Simulink to simulate dynamics and electromagnetic forces together with the constructed simulation framework. In order to consider the interference caused by irregularities, randomness and power spectral density (PSD) are used to analyze vibration interactions. We compared random signal inputs with PSD, greatly enhancing accuracy, and analyzed the vibrational interaction between car body and ride quality.

As a promising candidate for future high-speed transportation, the superconducting electrodynamic suspension (EDS) train have drawn a lot of attentions from the academic and industrial communities in the past decades. The dynamic response of EDS train is one of the key aspects that determines the safety and ride quality. In this work, the essential issue of EDS vehicle & x002F;guideway system dynamics is studied, including the magnet & x002F;rail interaction and the dynamic characteristics. The electromagnetic forces were provided by electromagnetic interaction between on-board superconducting magnet (SCM) and ground levitation & x002F;guidance coils in a null-flux superconducting EDS system. These forces were studied as a research premise for dynamic characteristics analysis of EDS train based on the vehicle & x002F;guideway coupling dynamics. A dynamic numerical model, with vehicle & x002F;guideway coupling dynamics of EDS system, was established to investigate its dynamic characteristics. The frequency and acceleration responses of the carbody in terms of the electromagnetic forces irregularity at different traveling speeds are presented and analyzed. The result indicates that superconducting EDS train can steadily run over the straight line at a speed of 600 & x00A0;km & x002F;h, meeting the riding comfort standard ISO2631.

In this paper, high magnetic fields generated by HTS magnet, instead of permanent magnet, was adopted to enhance the levitation property of HTS bulk on the fact that levitation force is positively related to the magnetic field strength. Based on the generally-accepted H-formulation, a validated 2-D axisymmetric finite element model was established to study and predict the levitation performances of HTS bulk in high magnetic fields. The fishtail effect Jc(|B|,T) dependence, which is closer to reality demonstrating unique magnetic dependence of HTS critical current in high magnetic fields, was employed to improve the effectiveness of numerical model. The results indicate that the levitation force could be greatly improved by taking magnetic field close to the peak field of fishtail effect Jc(|B|,T) curve. This work could serve as a vital method to predict the levitation performance of HTS bulk in high magnetic fields and a guide concerning how to choose external field in balance of performance and cost in future applications.

针对160 km/h速度等级动力集中动力车,采用SIMPACK软件建立了整车动力学计算模型,对比分析了JM3和LMA踏面与60 kg/m钢轨匹配时的动力车稳定性;基于振动模态,结合一系纵向刚度,分析了踏面磨耗过程中等效锥度变化对整车稳定性的影响,发现当车轮踏面等效锥度从0.01增大到0.5,在临界速度达到最高时,动力车失稳模态由车体侧滚转变为驱动摇头,随后临界速度下降.结果表明,采用JM3踏面动力车能获得更好的稳定性.

目前国内外针对高温超导块材磁悬浮性能的研究主要集中在较低的磁场强度下,为研究强磁场下高温超导块材的磁悬浮性能,本文拟采用高温超导线圈产生2～3 T的高强磁场作为背景磁场,以激发高温超导块材的“鱼尾效应”.同时,利用有限元仿真软件建立基于H法的二维轴对称模型,采用常用的Kim模型以及考虑超导块材的“鱼尾效应”模型两种方法计算超导块材在不同磁场强度下的悬浮性能.结果表明,高温超导块材的“鱼尾效应”在高场下能够极大地提高其悬浮能力.因此使高温超导块材所处的外磁场环境居于其自身的鱼尾效应场附近,可充分发挥高温超导块材高密度悬浮能力的优势,这对于高温超导块材的合理选择及运用具有一定的参考价值.

In a high-temperature superconducting magnetic levitation system composed of YBCO stacked magnet and permanent magnet guideway, the vibration of permanent magnet guideway is transmitted to the YBCO magnet due to the electromagnetic action.In this paper, the relationship between the transmission efficiency of vibration in the levitation system and both acceleration amplitude and the frequency of the vibration of permanent magnet guideway is studied through experiments.The results show that in the levitation system, the free vibration frequency of YBCO magnet is about 9 Hz;there is a positive correlation between the vibration transmission efficiency and the amplitude of the acceleration of the vibration of permanent magnet guideway, and a negative correlation between the vibration transmission efficiency and the frequency of permanent magnet guideway.