基于PAR-SMC磁悬浮列车系统仿真研究

磁悬浮列车系统有着非线性及开环不稳定的特点,采用传统滑模控制(SMC)会出现明显的抖振现象。在讨论单磁铁结构磁悬浮系统模型、对输入输出关系进行线性化的基础上,分析幂次趋近律的滑模控制(PARSMC)在单磁铁结构磁悬浮系统中应用的控制关系,并利用李雅谱诺夫稳定性理论分析该方法的稳定性。Matlab仿真结果表明幂次趋近律的滑模控制比传统的滑模控制有更好的控制性能,抖振明显削弱,位置信号误差更小,动态特性更好,鲁棒性更强。

悬浮间隙微分在磁浮列车系统中的应用

为了解决磁悬浮列车系统中普遍存在而难以解决的车轨耦合振动问题,以磁悬浮列车的车辆-轨道模型为研究对象,分析在普通反馈控制规律作用下容易产生车轨耦合振动的原因,提出并实现了在普通反馈控制规律的基础上,引入电磁悬浮间隙的微分信号来抑制车轨耦合振动的方法。考虑到实验过程中,由于噪声的影响,微分信号难以准确获取,介绍了一种能够抑制噪声的微分信号求取方法,给出了实验和仿真结果,验证了本文提出的控制方法的有效性。

两自由度磁悬浮控制系统的稳定性与Hopf分岔分析

建立了基于刚性轨道的两自由度磁悬浮控制系统的非线性动力学模型,利用Hopf分岔的Hurwitz判据,推导了PD控制下平衡点稳定以及失稳产生周期振动时控制参数应满足的条件.通过数值模拟得到的磁悬浮系统产生自激振动的临界条件很好地验证了理论分析的结果.通过比较还发现间隙反馈与速度反馈相比具有更强的控制效果,这一结论为反馈控制模式的选取提供了有效的理论依据.

高速磁浮列车用混合滤波器设计的仿真研究

高速磁悬浮列车系统的谐波是一种典型的强非线性、冲击性负荷,是一种重要的新型谐波源,在没有补偿措施时,它会带来较严重的电网谐波问题。针对高速磁悬浮列车系统谐波的特征,运用自适应谐波检测方法对谐波进行检测分离,通过有源滤波器和无源滤波器的有效配合,最终达到谐波抑制,改善功率因数,优化电网电能质量的目的。

A novel refined dynamic model of high-speed maglev train-bridge coupled system for random vibration and running safety assessment

Running safety assessment and tracking irregularity parametric sensitivity analysis of high-speed maglev train-bridge system are of great concern,especially need perfect refinement models in which all properties can be well characterized based on various stochastic excitations.A three-dimensional refined spatial random vibration analysis model of high-speed maglev train-bridge coupled system is established in this paper,in which multi-source uncertainty excitation can be considered simultaneously,and the probability density evolution method(PDEM)is adopted to reveal the system-specific uncertainty dynamic characteristic.The motion equation of the maglev vehicle model is composed of multi-rigid bodies with a total 210-degrees of freedom for each vehicle,and a refined electromagnetic force-air gap model is used to account for the interaction and coupling effect between the moving train and track beam bridges,which are directly established by using finite element method.The model is proven to be applicable by comparing with Monte Carlo simulation.By applying the proposed stochastic framework to the high maglev line,the random dynamic responses of maglev vehicles running on the bridges are studied for running safety and stability assessment.Moreover,the effects of track irregularity wavelength range under different amplitude and running speeds on the coupled system are investigated.The results show that the augmentation of train speed will move backward the sensitive wavelength interval,and track irregularity amplitude influences the response remarkably in the sensitive interval.

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.

Saturation influence of control voltage on maglev stationary self-excited vibration

This work addresses the saturation influence of control voltage on the occurring of self-excited vibration of maglev vehicle-bridge interaction system, which greatly degrades the stability of the levitation control, decreases the ride comfort, and restricts the cost of the whole system. Firstly, the interaction model of vehicle-bridge system is developed. Based on the interaction model, the relationship between the control voltage and vibration frequency is solved. Then, the variation of the effective direct component and fundamental harmonic are discussed. Furthermore, from the perspective of energy transmission between the levitation system and bridge, the principle underlying the self-excited vibration is explored, and the influence on the stability is discussed. Finally, in terms of the variation of the characteristic roots, the influence is analyzed further and some conclusions are obtained. This study provides a theoretical guidance for mastering the self-excited vibration problems.

UAQ4 Magnetic Levitating Train： Propulsion System for Urban Transportation

This paper discusses the design of the propulsion system of the UAQ4 （University of L＇Aquila, model 4） magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only magnetic levitating vehicle with resistance motion, except for aerodynamic drag and with energy consumption near zero at low speed. The feasibility of the system has been successfully verified and tested in the laboratory. Propulsion and braking are provided by a novel direct-current linear stepper motor, with the primary formed by permanent magnets distributed on central beam of the track, and the secondary by coils on board the vehicle, instead of the present alternate current linear motors that have well-known disadvantages. The motor working principles are described, and its performances are analyzed, by a finite element numerical model which allows modifying the most important parameters of the system. The main components of a full scale motor for urban transportation are measured and discussed.