Integrated Sliding Mode Velocity Control of Linear Permanent Magnet Synchronous Motor with Thrust Ripple Compensation

In this paper,a compound sliding mode velocity control scheme with a new exponential reaching law(NERL)with thrust ripple observation strategy is proposed to obtain a high performance velocity loop of the linear permanent magnet synchronous motor(LPMSM)control system.A sliding mode velocity controller based on NERL is firstly discussed to restrain chattering of the conventional exponential reaching law(CERL).Furthermore,the unavoidable thrust ripple caused by the special structure of linear motor will bring about velocity fluctuation and reduced control performance.Thus,a thrust ripple compensation strategy on the basis of extend Kalman filter(EKF)theory is proposed.The estimated thrust ripple will be introduced into the sliding mode velocity controller to optimize the control accuracy and robustness.The effectiveness of the proposal is validated with experimental results.

Three-dimensional Electromagnetic Characteristics Analysis of Novel Linear Synchronous Motor under Lateral and Yaw Conditions of MAGLEV

Dynamic stability analysis of superconducting electro-dynamic maglev train under lateral and yawing motion condition is the key research content.The novel three-dimensional electromagnetic model of integrated linear synchronous motor in electro-dynamic maglev train with yawing operation condition is proposed,which can not only simultaneously achieve the propulsion,levitation and guidance performances of maglev vehicle,but also analyze the dynamic stability performance of train with yawing condition.The three-dimensional analytical method is introduced for analyzing the electromagnetic force characteristics of the linear synchronous motor with the yawing operation condition.Firstly,the topology structure and operation principle of the linear synchronous motor with yawing attitude are proposed.Secondly,the three-dimensional analytical model and expressions of electromagnetic characteristics are obtained by equivalent circuit method and Fourier decomposition method,such as levitation force,guidance force,propulsion force and yawing torque,etc.Finally,the three-dimensional electromagnetic characteristics of the linear synchronous motor are calculated under yawing operation conditions of maglev train,and the correctness of the analytical theory is verified by the finite element analysis and measured data on the test line.

Electromagnetic Analysis and Optimization of High-speed Maglev Linear Synchronous Motor Based on Field-circuit Coupling

High speed maglev train has become a new non-contact transportation mode mainly studied in recent years because of its non-sticking and high speed characteristics.Firstly,the finite element model of the long stator linear synchronous motor(LSM)is established based on the structure of the test prototype.After calculation,it is compared with the experimental data and verified.On this basis,a field-circuit coupling model based on inverter circuit is established,and the influence of carrier wave ratio change on the output characteristics of LSM is calculated and analyzed.Finally,the filter circuit is introduced into the field-circuit coupling model,and the influence of the filter circuit on the output characteristics of the LSM is compared and analyzed.

A Permanent Magnet Linear Synchronous Motor Drive for HTS Maglev Transportation Systems

A permanent magnet linear synchronous motor （PMLSM） for a high temperature superconducting （HTS） maglev system has been studied, including the motor structure, control strategy, and analysis techniques. Finite element analysis （FEA） of magnetic field is conducted to accurately calculate major motor parameters. Equivalent electrical circuit is used to predict the drive＇s steady-state characteristics, and a phase variable model is applied to predict the dynamic performance. Preliminary experiment with a prototype has been made to verify the theoretical analysis and the HTS-PM synchronous driving technology.

Development of High-Thrust and Double-Sided Linear Synchronous Motor Module For Liquid Crystal Display Equipment

Recently,there is an increasing requirement for controlling linear motion up to a few hundred of millimeter strokes in the area of the liquid crystal display(LCD) production equipment.The requirements of the motion system for LCD production equipment are high acceleration and high velocity with positioning accuracy.To satisfy these requirements,it has to be designed with the high-thrust force and low velocity ripple.In this work, high-thrust and double-sided linear synchronous motor (LSM)module is proposed and the developed high-thrust and double-sided LSM module is verified by performance test.

Optimal design of auxiliary-teeth to solve circulation current reduction of permanent magnet linear synchronous motor

A discontinuity of magnetic circuits according to the end effect is generated in the permanent magnet linear synchronous motor （PMLSM）. Due to the unbalanced back electro-motive force （EMF） and impedance produced, unbalanced current is generated. The cireulatin8 current, which is caused by a decrease in the thrust, is generated by the unbalanced current. The optimal design of auxiliary-teeth at the end of the mover was carried out to solve the unbalance of phase by using design of experiment （DOE）, and compared with the basic model through finite element analysis （FEA）. As a result, the auxiliary-teeth model compensates for the decrease of thrust caused by the unbalanced phase. Also, this model is proven to reduce the detent force by the vibration and noise of the PMLSM and copper loss caused by the circulating current.

基于比例谐振内模扩张状态观测器的PMLSM推力波动抑制策略

定位力是永磁同步直线电机(PMLSM)产生推力波动的主要原因,导致振动和噪声,恶化驱动系统运行性能。针对这一问题,该文提出一种基于比例谐振内模扩张状态观测器(PR-IMESO)的PMLSM推力波动抑制策略以提高系统控制精度和运行性能。首先,对PMLSM推力波动进行建模与分析,针对推力波动中占比较大的定位力分量,根据内模原理研究考虑定位力模型的内模扩张状态观测器(IMESO),并在观测器中引入谐振项以加强对二次脉动定位力的抑制。所提出抑制策略对PMLSM定位力具有良好的观测及补偿能力,还可对其余未建模的复杂动子推力波动进行抑制,具有较好的推力波动整体抑制效果。最后,在一台750 W的PMLSM实验平台上验证所提出抑制策略的有效性。

考虑端部效应的动子无源型Halbach磁悬浮永磁直线电机电磁力分析

针对光刻机等高精确度定位平台无摩擦、无接触、无噪声需求,提出一种采用动子无源型平移和悬浮一体化Halbach磁悬浮永磁直线电机以实现定位平台的无摩擦悬浮及长距离定位运动。为了精确分析该类电机的悬浮力和推力特性,提出一种考虑动子永磁体端部效应的电机磁场解析模型并采用傅里叶分解法得到Halbach阵列永磁体磁场解析式。基于此磁场解析模型,通过洛伦兹力法得到了动子电磁力解析模型,并基于正交分解法推导了电机悬浮力和推力解耦的电磁力模型。结合有限元仿真对建立的电磁模型进行了对比验证,在此基础上,设计并制作了一台10极12槽样机,通过搭建实验平台进行推力和悬浮力测试,将实验测试值与有限元仿真值和解析值对比验证了所提出方法的准确性和快速性。

电磁发射用永磁同步直线电机磁场解析及推力波动优化

针对电磁发射用永磁同步直线电机的磁场解析及推力波动优化问题,建立单边发射电机磁场解析模型,利用矢量磁位及边界条件,分别对次级Halbach永磁阵列及初级六相绕组磁场进行解析,得到气隙磁场分布,进而建立单边发射电机主要结构参数与电磁推力间的函数关系。选取永磁阵列极弧系数及厚度、初级绕组宽度及厚度4个参数作为优化变量,利用遗传算法寻找设计变量的最优组合,使发射电机单边电磁推力波动最小化。分析结果表明:磁场解析结果精度较高,电磁推力计算误差满足工程分析的需要;优化后的单边发射电机平均推力提升1.21%,峰均力比下降62.688%,通过解析及仿真结果的对比验证了理论推导的正确性及优化方法的合理性。

考虑悬浮牵引耦合的常导高速磁浮列车牵引性能仿真

常导高速磁浮列车长定子直线同步电机(LLSM)定子电枢电流和动子励磁电流产生的磁动势共同作用形成气隙磁场,实现车辆悬浮和牵引,所以悬浮力和牵引力之间存在耦合。基于MATLAB/Simulink建立了牵引供电系统的仿真模型,采用不考虑悬浮牵引耦合的LLSM数学模型,在恒定励磁电流条件下仿真计算了牵引性能;采用考虑悬浮牵引耦合的LLSM数学模型,其以有限元仿真数据为样本库,基于线性回归最小二乘方法拟合得到,在恒定悬浮力条件下仿真计算了牵引性能。通过对比两种仿真结果,分析了耦合作用的影响。

考虑悬浮导向间隙变化的长定子直线同步电机力性能分析

常导高速磁浮列车长定子直线同步电机由于特殊的分离结构,气隙由悬浮与导向系统决定,导致牵引力与悬浮力容易受到悬浮与导向系统性能的影响。研究了一个长定子段下垂、悬浮磁极模块纵向倾斜和横向偏移三种工况对气隙的影响,基于有限元软件建立了2D与3D有限元模型,计算分析了长定子直线同步电机的牵引力和悬浮力,揭示了气隙变化对力的影响规律。分析结果可以为高速磁浮列车的牵引系统设计与控制提供参考。

基于补偿绕组的永磁直线同步电机推力波动研究

为抑制永磁直线同步电机的推力波动,提出了一种引入补偿绕组的永磁直线同步电机,具有推力波动低、推力损失小等特点。首先,以12槽14极永磁直线同步电机为对象,优化端部齿参数降低了定位力基波幅值;其次,采用端部力补偿绕组削弱了定位力的二次谐波;再次,采用相补偿绕组较大程度上平衡了三相反电动势。有限元仿真结果显示,在额定负载条件下,引入补偿绕组的结构的推力波动率与优化前相比下降了28.51%,且推力保持不变,验证了其有效性。

高速磁悬浮用直线同步电机电流控制策略研究

高速磁悬浮列车采用直线同步电机作为其驱动装置,其电流控制效果直接影响列车运行稳定性及舒适性。针对直线电机功率较大的特点,单相驱动时采用多H桥串联方案,并可实现高低速运行时驱动拓扑切换,矢量控制中电机电流经过坐标变换后dq轴电流存在严重的交叉耦合,并且耦合分量随着车速的增加不断增大,从而降低了电流控制性能。为了提升电机动态控制效果,提出复矢量电流控制方法,并采用虚拟电阻解决了不同调制方式下电流振荡问题,通过半实物仿真平台对控制性能进行了验证,仿真和实验结果表明了电流控制策略的可行性和有效性。

Design of relative position sensing system for high-speed maglev train

In the high-speed maglev system,accurate real-time information of the train position is essential forstable,safe and efficient train operation.To detect the relative position of the high-speed maglev trainfrom a reference position,a location method based on long stator slot detection was proposed.Besides,aprototype system has been successfully developed.The hardware structure of the system,as well as itsworking principle was described.Moreover,a subdivision algorithm for calculating the pole location anglesignal was elucidated.Experiments show that the proposed method is feasible.The technical indexes ofthe detection system satisfy the requirements of the vehicle operation control system.The relative positionsensing system can be put into practice.

永磁直线同步电机Halbach阵列电磁激振力建模

为实现永磁同步直线电机Halbach阵列电磁激振力的精确计算,首先建立了考虑边端效应的伪周期电磁场子域解析模型,对永磁阵列电磁特性进行精确刻画;然后,基于永磁体磁能分布原理修正相互作用磁能表征式,继而推导出基于局部虚功位移法永磁体电磁激振力计算公式;最后,通过有限元验证了永磁阵列电磁场模型,并通过堵驻推力试验间接验证了电磁激振力计算的精确性。

中速磁浮无铁心永磁直线同步电机的结构优化

中速磁浮列车采用单边长初级无铁心永磁直线同步电机(IPMLSM)作为牵引电机,因为这种电机具有结构简单、运行平稳、无轮轨摩擦以及法向吸引力接近于0等优点,但是由于该电机定子无铁心,导致其推力密度较小,且永磁材料使用过多及定子绕组沿轨道长距离铺设,使电机效率进一步降低。为了提高电机性能,在IPMLSM基本结构的基础上,提出一种新型永磁体装配结构,可提升电机推力密度;并根据长定子IPMLSM绕组的特点,优化绕组导体截面,获得适用于中速磁浮列车IPMLSM定子绕组导体的宽与高之比,进一步提升电机的推力密度。最后,制作IPMLSM小型样机实验装置,对比实验结果验证了所提改进结构的优越性。

高速磁浮列车长定子直线同步电机铁耗分析

常导高速磁浮列车采用长定子直线同步电机(LLSM)驱动,其定动子铁耗与运行速度紧密相关,准确计算铁耗并分析其影响因素对更高运行速度的磁浮列车非常重要,本文基于有限元分析了LLSM的铁耗。根据磁场特性为LLSM建立了三种仿真模型,分别计算没有被动子覆盖区域的定子铁心磁场和被动子覆盖区域端部、中间的定动子铁心磁场,采用快速傅里叶变换得到了磁通密度基波和高次谐波分量;基于通用铁耗分立计算模型计算了各次磁通密度分量产生的铁耗,再根据叠加原理把三个区域磁通密度分量产生的铁耗相加就可以计算得到一段1.2 km长定子下LLSM的铁耗;对比不同速度下的铁耗得到了运行速度对铁耗的影响规律,同时也分析了铁心材料对铁耗的影响。结果表明,长定子铁耗主要由磁通密度的基波和5次、7次谐波产生,而动子铁耗则主要由齿槽效应引起的6次谐波磁通密度产生,两部分铁耗都随着运行速度的提高而快速增大。

空心永磁直线同步电机推力波动分析

本文分析了一个U型Halbach空心永磁直线同步电机(IPMLSM)的推力波动。首先推导了dq0坐标系下的推力方程和电感方程,以此分析了电枢绕组互感不对称对推力波动的影响,然后基于有限元仿真得到的三相不对称电流,利用快速傅里叶变换和对称分量法,分析了电流谐波分量和电流不对称性对推力波动的影响。分析表明,电流不对称导致的负序电流是IPMLSM推力波动的主要原因。研究结果为该类电机的优化设计提供了依据。

同极同槽双边平板型PMLSM的设计及推力优化研究

为降低直线电机的推力波动,提出一种同极同槽双边平板型永磁直线同步电机(Permanent Magnet Linear Synchronous Motor,PMLSM),且采用不同方法优化其结构参数.为确定电磁设计方案,根据同极同槽双边平板型PMLSM的结构特点和旋转电机的设计方法,推导出适用该电机的电磁设计公式,并建立二维有限元仿真模型进行分析和验证.随后采用田口法筛选优化变量,分别通过单参数扫描和基于克里金代理模型的粒子群算法进行优化.结果表明,在满足推力不低于600 N的前提下,推力波动大幅降低,且永磁用量减少了13%.

交叉耦合对永磁直线同步电机电磁推力的影响

永磁直线同步电机各项性能指标均与电感参数密切相关,获得更为精确的电感参数对电机性能分析尤为重要。为定位更加准确,提高控制精度,解决在大电流高饱和情况下交叉耦合对永磁直线同步电机电磁推力影响较大的问题,在传统永磁直线同步电机数学模型的基础上,采用考虑交叉耦合的数学模型计算电感参数,并以12极54槽有限元模型为例进行仿真,分析励磁电流增大对最大推力的影响,得到交叉磁阻推力的存在改变了总的磁阻推力进而影响了电磁推力的增长幅度的结论,为后续电机优化设计提供了研究方向。