基于解耦策略的直线感应牵引电机法向力自适应最优控制

中低速磁悬浮列车和部分地铁车辆均采用直线感应牵引电机作为驱动机构,该电机特有的边缘效应和法向力对直线感应牵引电机的效率以及性能均产生很大的负面影响,因此直线感应牵引电机采用常规的电传动控制策略并不能取得良好的控制效果。该文充分考虑边缘效应的影响,建立了直线感应牵引电机的数学模型。将推力与磁通进行解耦,并分析磁通、推力与电流控制环节的非线性与时变性,提出了神经自适应控制的设计方法。分析了法向力的组成与特性,得出其数学表达式,以推力与磁通解耦为基础,结合最优化理论,考虑多个优化目标建立损耗最小函数,实现直线感应牵引电机的损耗最优控制。计算机仿真与实验对所提控制策略与传统控制策略进行对比,验证了该方法在典型工况下的有效性。     

IN-PHASE COMPENSATION FOR A HIGH SPEED LINEAR INDUCTION MOTOR

Abstract

The performance of a high speed linear induction motor is considerably degraded due to end-effects. This is particularly so as regards the force produced. In this paper, a new method called “In-phase compensation” method has been described to eliminate the end-effect force. Unlike the conventional methods, this method does not require phase angle control but only magnitude control of compensating current even for varying slips. A comparison of developed forces by this method of compensation has been made with an equivalent uncompensated LIM.     

基于逆线性二次型的感应电动机的控制系统研究

提出了基于ILQ(逆线性二次型)的感应电动机的控制系统的设计方案。使用反馈线性化的方法实现感应电动机d-q轴系统的精确线性化;然后通过应用ILQ的优化设计方法,设计了感应电动机优化控制系统;并利用理论结果进行了实验验证。结果证明,与传统带有PI调节器的感应电动机矢量控制系统相比,该方法跟踪速度明显提高,且具有较强的鲁棒性。     

基于自适应转子电阻估计器的感应电机逆解耦控制

提出了一种具有自适应转子电阻估计器的感应电机的逆解耦控制方法.首先通过非线性状态反馈获得感应电机的逆系统,将感应电机这个多变量、非线性、强耦合的对象动态解耦成转速与转子磁链两个二阶子系统;然后,采用模型参考自适应系统（MRAS）理论来设计转子电阻估计器,在线估计时变的转子电阻,从而保证在整个电机运行区域内,转速与磁链之间的输入输出解耦关系不变;最后,分别设计线性控制器对转速与磁链子系统进行闭环控制.仿真结果表明,提出的控制方案具有优良的动态和静态性能,且对电机参数变化具有强鲁棒性.     

基于异步电动机动态模型的间接转矩控制策略研究

基于异步电动机的动态数学模型,分析了间接转矩控制技术的基本原理,给出了实现间接转矩控制器的具体算法。在此基础上,以200kW异步电动机作为控制对象,对使用间接转矩控制技术的异步电动机调速系统进行了试验研究。实验结果表明,间接转矩控制策略能够有效地改善调速系统的低速性能。     

Rotor field oriented control strategy with harmonic currents closed-loop control for five-phase induction motor

In order to solve the problems of harmonic currents in the conventional vector control of multiphase induction motor, the rotor field oriented control (RFOC) strategy with harmonic current closed-loop control is proposed in the paper. Based on the transform theory of the multiphase system and the RFOC strategy of three-phase induction motor, the mathematical modulation of RFOC for five-phase induction motor is modeled. The fundamental current and the second order harmonic current can be controlled independently after being decoupled. The proposed strategy is implemented with a board microcomputer that uses TMS320F28335 DSP. The experimental results show that the proposed RFOC strategy with harmonic current closed-loop control has outstanding dynamic and static performance.     

用于电磁弹射的容错型初级永磁直线电机特性

提出一种应用于电磁弹射的新型双边容错型初级永磁型直线电机,该种电机具有次级结构简单的特点。首先,本文给出了电机的结构和工作原理。其次,在采用二维有限元对电机的静态推力特性分析基础之上,通过能量法对电机推力公式进行了推导分析,并且对电机的容错特性进行了分析。然后,采用瞬态有限元对电机在正常和断路故障下的推力变化进行了仿真分析,并对电磁弹射过程电机运行情况进行了仿真分析。最后,通过一个同比例缩小的小尺寸同类电机进行了实验研究,验证了电机的推力特性和容错性能。仿真和实验结果显示该电机具有高的推力密度、较小的推力波动和简单的控制策略,在电磁弹射系统应用中具有很好的前景。     

螺旋桨飞机模型风洞实验驱动电机发热研究

针对螺旋桨飞机模型带动力风洞实验要求,通过气动性能分析提出驱动电机的技术指标,在满足结构约束的条件下,通过合理设计电机的电磁负荷、校核发热、采用高效冷却装置等,研制出短时工作制高功率密度三相异步电机。重点研究该高功率密度电机的发热与冷却问题。实验结果表明,使用该方法设计的电机满足了风洞实验要求,具有较高的性价比和较强的工程应用价值。     

异步电动机软起动过程中的振荡

针对异步电动机软起动过程中出现的电流、电磁转矩以及转速振荡问题,建立了其软起动通用仿真模型,分析了异步电动机软起动过程中引起振荡的影响因素及其产生原因,提出用控制关断角的方法,即以电流关断时刻为基准,在电机软起动过程中使关断角逐渐减小为零来抑制振荡。通过仿真验证了该控制方法的正确性,并在此基础上研制了基于关断角控制的异步电动机软起动装置并进行了样机试验,实验结果验证了理论分析的正确性。     

基于磁链与负载观测器的异步电机反步滑模控制

针对参数摄动及负载转矩未知且变化会影响异步电机速度控制的问题,设计了一种改进型指数趋近律的滑模转子磁链观测器,用于估算电机转子磁通值,同时将磁通观测值用于负载转矩的估计。引入磁链误差、转速误差,通过反步滑模控制算法,将转子磁通与负载转矩的观测值用于异步电机控制。在转子电阻摄动与负载转矩未知且变化的情况下,将该控制策略与自适应反步控制方法进行实验结果对比。实验结果表明,该控制策略的响应速度快且跟踪精度高,提高了异步电机速度控制系统的抗干扰性能。最后,提出一种转速软给定方法,实验表明该方法能有效抑制转速变化时刻定子电流与电磁转矩的急剧增加,进一步改善了电机系统的性能。     

Motor performance investigation of an indirect matrix converter with a reactor‐free boost converter

This paper describes a three‐phase power converter which utilizes the neutral point of an induction motor and demonstrates the performance of the motor using the proposed method under various operating conditions. Several motor test results, such as the speed–torque characteristic, the torque impact, and the acceleration–deceleration characteristic, are included to confirm the performance of the induction motor. The structure of the proposed circuit consists primarily of an AC/AC converter [indirect matrix converter (IMC)] and a boost converter connected to the neutral point of the induction motor. In addition, this paper also proposes a method to reduce the ripple found in the battery current. Several experimental results show that the motor works well, and even the leakage inductance is utilized in the boost converter. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

轻型锰铁转子导条在三相异步电动机中的应用

通过阐述轻型锰铁转子导条的选用,以提高三相鼠笼感应电动机的起动性能。虽然感应电动机以普遍性和简单化受欢迎,但是起动转矩低,起动电流达到额定电流的5~8倍。解决该问题的一个简单方法是引入新型轻锰铁材质的转子导条,通过錳铁转子的"集肤效应"来提高起动时的功率因数。本文阐述了相关的电磁理论来论证该论点,通过计算机模拟和测试一台0.75kW的感应电机来证实其有效性。     

感应电机的神经网络逆系统线性化解耦控制

提出了一种新的感应电机的线性化解耦控制方法，其特点是不依赖于对象的精确数学模型与参数。通过用静态神经网络加积分器来构造感应电机的逆系统，将感应电机这一多变量、非线性、强耦合的复杂对象动态解耦成转速与转子磁链两个二阶线性子系统，然后运用线性系统理论进行综合。仿真与初步的实验结果表明系统具有优良的静态及动态解耦性能，且对电机参数的变化与负载扰动具有较强的鲁棒性。     

分段供电直线感应电机动子不对称模型及参数计算

对于分段供电直线感应电动机,由于动子两端开断,动子等效互感存在较大的不对称,仅控制定子电流对称,不能消除动子负序电流引起的两倍转差频率力波动。基于动子涡流产生的机理,提出了动子等效绕组的形式,推导了动子不对称分布参数模型,得出在动子行程的大部分阶段,电机的不对称参数是基本恒定的。提出了动子不对称参数的计算方法,通过有限元建模进行推力仿真,并在大功率加速实验平台上开展动态试验,计算了动子不对称电感参数,仿真和实验计算结果与理论值吻合良好。动子不对称参数计算方法,可以为分段供电直线感应电机的电磁设计和优化控制提供参考。     

Beitrag zur Jochfluß-Verteilung in asynchronen Linearmotoren

Übersicht In der vorliegenden Arbeit wird die Verteilung des Rückenflusses in asynchronen Linearmotoren unter vereinfachenden Annahmen untersucht. Die durchgeführten Experimente zeigen, daß das gewählte Rechenmodell gute Näherungswerte liefert.

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Contents The presence of discontinuities in the magnetic circuits of linear induction motors has led to the phenomenon known as end-effect or edge-effect. A number of attempts have been made to reduce the adverse influence of end-effects. Computer programs are available today for the calculation of these effects. Little attention, however, has been paid to the distribution of the flux density in, the yoke of linear induction motors. This paper presents some theoretical considerations concerning this topic. To verify the results, tests were performed on a single-sided linear induction motor.

     

一种新型的电机参数离线辨识系统

在实际工程应用中,常规空载实验和堵转实验辨识电机参数的方法难以实现,且辨识精度不高,针对此问题,设计了一种基于TMS320F2808的异步电机参数辨识系统.该系统能够通过直流实验、单相交流实验以及空载实验代替常规辨识方案对工程现场电机的参数进行辨识.这里论述了异步电机参数辨识系统的设计和实现过程,并对电机参数辨识中出现...     

Vector theory of an induction motor

Basic concepts for the vector theory of an induction motor are proposed. The vector method is used to derive new systems of equations and limits for torques, phase angles and absolute values of currents, and the flux linkage for nonlinear saturation. The theory, which is confirmed by the experiment, may be used for the system optimization of induction motors and asynchronous electric drives based on the energy performance criteria.     

Intelligent control of induction servo motor drive via wavelet neural network

This study presents an intelligent control system for an induction servo motor drive to track periodic commands using a wavelet neural network (WNN). With the field orientation mechanism, the dynamic behavior of the induction servo motor drive system is rather similar to a linear system. However, the uncertainties, such as mechanical parametric variation, external disturbance, unstructured uncertainty due to nonideal field orientation in transient state, and unmodelled dynamics in practical applications influence the control performance. Therefore, an intelligent control system that is an on-line trained WNN controller with adaptive learning rates is proposed to control the rotor position of the induction servo motor drive. The adaptive learning rates are derived in the sense of discrete-type Lyapunov stability theorem, so that the convergence of the tracking error can be guaranteed in the closed-loop system. In the whole design process, the strict constrained conditions and prior knowledge of the controlled plant are not necessary according to the powerful learning ability of the intelligent control system. With the proposed intelligent control system, the controlled induction servo motor drive possesses the advantages of good tracking control performance and robustness to uncertainties under wide operating ranges. The effectiveness of the proposed control scheme is verified by both simulated and experimental results.     

直线感应电动机气隙大小对其起动性能的影响

以一台起动推力为225N的直线感应电动机为例进行分析,将整个电机模型作为求解域,采用有限元方法对电机的起动过程进行了仿真计算,并对电机起动过程进行了实验,实验结果验证了仿真计算的正确性,在磁场数值计算的基础上分析了气隙大小变化对电机性能的影响。     

三相电容式电机

阐述一种新型的节能电机——三相电容式电机。基于单相电机的分析方法,根据三相电容式电机的结构,对其性能方程进行探讨,得到运转电容的最优配置。最后,将对三相电容式电机的样机进行实验,实验数据与理论计算结果吻合较好。通过理论分析和实验证明,三相电容式电机相比传统的三相电机,其功率因数和效率确实有所提高,其性能更为优越。