Compact wheel direct drive for EVs

Concerning the application of slotless axial-flux PM motor (AFPMs) in electric vehicle drives, this article deals with the development of a 16-pole AFPM prototype which is used in the propulsion system of an electrical scooter. The proposed AFPM prototype has 45 Nm peak torque and 6.8 kg mass of active materials, and it is coupled directly to the scooter's rear wheel. In the following, the authors discuss the design and construction of the motor prototype and report experimental results taken from machine laboratory tests. Finally, they give details concerning the motor drive arrangement used in an electrical scooter prototype     

Basic principle and design criteria of axial-flux PM machineshaving counterrotating rotors

Axial-flux PM machines are particularly suitable for application in electrical drives devoted to ship propulsion, since they allow the elimination of the large-power gearbox used in conventional systems. In consideration of that, this paper deals with a novel slotless axial-flux PM machine topology which is characterized by the synchronous counterrotation of the two machine rotors. Such a new machine topology can find application in the direct driving of two counterrotating propellers, which may be used in ship propulsion systems to recover energy from the rotational flow of the main propeller slip stream. In this case, the use of an axial-flux machine having counter-rotating rotors allows an improvement in terms of weight and efficiency, since the epicyclic gear otherwise required for the motion reversal can be avoided. The paper discusses the stator winding arrangement which allows the opposite motion of the machine rotors and reports experimental results taken from a small-size machine prototype     

High-performance PM synchronous motor drive for an electricalscooter

In this paper, the design of a full electrical system for an electrical scooter is presented. The paper explains the design choices that have been made to satisfy the typical main requirements for an electrical vehicle. According to them, an interior permanent-magnet synchronous motor has been incorporated in a drive able to control the motor both in the constant-torque (constant-flux) and in the constant-volt-ampere (flux-weakening) regions. Experimental results carried out on a system prototype are also included in the paper     

PM motors for direct driving optical telescope

This article details the task of developing the drive systems for VLT (Very Large Telescope) control. The project entails the realization and the coordinated operation of four 8 m diameter optical telescopes in Chile for the period 1995-1998. A direct drive system has been chosen as the optimal drive solution from a performance standpoint. It consists of a segmental dual axial air gap brushless motor which is an unusually large torque motor, which must be manufactured piecewise and assembled on-site. Furthermore, the torque motor must couple in the stiffest possible way to the relatively light telescope assembly, and the thermal perturbations to the environment must be minimized. Finally, in spite of their very large size, the torque motors must be controlled with a very high control bandwidth; the torque slew rate must be extremely steep. The authors describe the design of the drive system including motor torque ripple. Finite element analysis of the motor is also discussed     

一种新型电动车用宽调速永磁电机驱动系统

介绍了一种新型电动车用永磁电机宽调速驱动系统。在采用新型电机结构的基础上．基于标量算法的快速电流追踪控制满足了高性能的调速要求。在高速下．利用变压器电势来削弱电机旋转电势。从而实现了高于基速的恒功率运行．扩展了电机的调速范围。     

High‐performance doubly fed induction machine drive system using predictive direct torque control drive system fed by indirect matrix converters

This paper presents a novel predictive direct torque control for doubly fed induction machine based on indirect matrix converter (IMC), which is characterized by its simple structure, minimal‐torque ripple, and constant switching frequency. Nowadays, the control strategies based on predictive methods have proved their efficiency to improve drive systems capabilities. So, in this paper, one of the best predictive methods that have recently been suggested for doubly fed induction machine drive systems is applied to IMC. The purpose of this combination is to modify the control parameters and size/volume reduction of drive system structure, which is difficult to achieve in conventional systems based on voltage source inverters. The good tracking behavior with reduced torque and flux ripple for both motoring and generating modes as well as removing bulky electrolytic capacitor from the DC link of a converter resulted by using three vectors, two active vectors together with one zero vector per switching period, and applying these vectors to the inverter stage of IMC. To improve the motor drive system performance and reduce losses caused by snubber circuits, the rectifier four‐step commutation method in rectifier bridge is used. In the inverter stage, the predictive direct torque control method is employed. The simulation results of the proposed model confirm its effectiveness and accuracy. Copyright © 2013 John Wiley & Sons, Ltd.     

AC brushless drive with low-resolution Hall-effect sensors for surface-mounted PM Machines

An ac brushless drive in which Hall-effect sensors are used as rotor position sensors is presented in this paper. Three different methods to obtain a high-resolution position estimation from the low-resolution sensors are described and compared through simulation and experimental testing. The proposed control algorithm's most innovative feature is its adaptability to the entire speed range, including startup, when using any of the three estimation algorithms. The control algorithm has been implemented and tested in order to drive a slotless axial-flux permanent-magnet (PM) machine for domestic appliance applications.     

A novel direct torque control for interior permanent-magnet synchronous machine drive with low ripple in torque and flux-a speed-sensorless approach

A novel direct torque control (DTC) scheme for an interior permanent magnet synchronous machine (IPMSM) is proposed in this paper, which features low torque and flux ripple and almost fixed switching frequency. The torque and flux ripples have been significantly reduced compared with those of the basic DTC reported in the literature. A speed estimation scheme is integrated with the proposed DTC scheme in order to achieve a fully sensorless high-performance IPMSM drive.     

Dual stator winding induction machine drive

A new dual stator winding induction machine drive is described in this paper. The proposed induction machine consists of a standard squirrel-cage rotor and a stator with two separate windings wound for a dissimilar number of poles. Each stator winding is fed from an independent variable-frequency variable-voltage inverter. The proposed drive offers such advantages as speed sensorless operation, better reliability, and more flexibility to manipulate the resultant torque-speed curve of the motor. In the proposed drive, zero-speed operation is achieved by independently controlling the two sets of stator currents, hence, maintaining a minimum electrical frequency independent of the mechanical speed. This feature is especially important to minimize the negative impact of the stator resistance influence at low-speed operation and it greatly simplifies the implementation of speed sensorless control schemes. The drive is well suited for either constant volts per hertz or field-oriented (FO) operation. Circulating harmonic currents, common to most dual stator machines, are eliminated by the dissimilar pole number in each stator winding     

定子永磁型双凸极电机的转子设计

目前,对双凸极永磁（Doubly salient permanent magnet,DSPM）电机驱动系统研究时间相对较短,尚有不少技术问题有待进一步深入探讨.但鉴于已了解双凸极永磁电机驱动系统具有的优点、特征以及合理使用该系统,结合实践,对定子永磁型双凸极电机的转子进行了设计,分析了双凸极永磁电机的电流斩波控制和角位置控制方式,阐述了功率变换器的电路结构和信号检测原理.     

参数优化的支持向量机机车车轮状态检测

针对车轮状态检测中存在的类间样本误分代价不等的问题,利用自适应变异粒子群算法对代价敏感支持向量机(CS-SVM)的参数进行优化。该方法从数据样本中提取不均衡数据创建训练样本,采用代价敏感的支持向量机建模。为了提高分类的精确度,选用径向基核函数优化模型结构。提出了自适应变异粒子群算法优化CS-SVM的两个不同惩罚参数和核函数,并用参数优化的代价敏感支持向量机实现重载机车车轮状态分类。最后,通过仿真验证,车轮状态检测的平均准确率可以达到95%,平均处理速度24 s,具有实时性和较强的鲁棒性,能够满足重载机车运行要求。     

汽车轮毂轴承伺服压装测控系统的设计

根据汽车轮毂轴承压装的基本原理和工艺要求,设计了基于工控机和PLC的伺服压装测控系统,实现了汽车轮毂轴承的压装和质量检测。系统通过PLC和伺服定位模块实现对伺服电机的控制,采用高精度的位移和压力传感器,达到了测试的精度要求和节拍要求。通过在上海汽车生产线上的生产实践证明,该系统具有节能、运行稳定和操作方便等优点,保证了生产效率和产品质量。同时该测控系统中的设计方法对于其他汽车零部件的测控系统设计具有良好的借鉴意义。     

森兰SB70变频器在直进式拉丝机中的运用

本文介绍了森兰SB70变频器在直进式拉丝机中成功的应用案例,详细的讲述了运用森兰成熟的矢量控制技术及PID功能,实现了高动态响应的恒张力控制。应用结果表明,此方案稳定、可靠,实现成本低。     

An automatic torque ripple compensation system for direct drive motors

A serious problem in motion control is the occurrence of torque ripple. Since a direct drive (DD) motor with a magnet rotor uses a rare-earth magnet, the torque ripple is more serious than that of conventional servomotors. This paper presents an auto-compensation of torque ripple using a software-implemented torque observer. The frequency and amplitude of torque ripple can be obtained in the controller by using the estimated torque from an observer, and the autonomous generation of a compensating current component for a torque ripple is possible. The proposed algorithm has been verified by experiments.     

Electric drive with a field-regulated reluctance machine

Improved power characteristics of an electric drive with a field-regulated reluctance machine are demonstrated. These characteristics are confirmed by refined finite-element calculations.     

Fixed-switching-frequency DTC control for PM synchronous machine with minimum torque ripples

In this paper, fixed-frequency direct torque control (DTC) of a permanent magnet synchronous motor (PMSM) is presented. In this method, the stator voltage vector is generated according to the increase stator flux components in the stationary frame ( , ). A control algorithm based on predictive control to reduce the effect of the computing time on the stator flux vector position is also presented. The implementation of this method in the case of a PMSM, which is done without hysteresis regulators, is simple and does not require any filter. Simulation and experimental results show that the proposed method reduces the torque ripple while achieving a good dynamic response.     

Methods to control wheel locks and wheel spins on low friction coefficient roads for front and rear wheel independent drive type electric vehicles (FRID EVs)

Wheel lock and spin control methods suitable for front and rear wheel independent drive type electric vehicles (FRID EVs) are studied here. Wheel locks and spins occur easily when braking and driving operations such as deceleration and acceleration are performed on bad roads with low friction coefficient such as wet or frozen roads. The methods studied here are characterized by using the structural feature of FRID EVs which can freely distribute the driving and braking torques to front and rear wheels according to running and road surface conditions. These wheel locks and spins occurring when braking and driving on bad roads are controlled by properly distributing the braking and driving torques to front and rear wheels in consideration of the load movement caused by braking operations and slip ratios of the front and rear wheel sides. The effectiveness of the wheel lock and spin methods studied here is verified through simulations and experiments on various roads with a low friction coefficient using a prototype EV with the FRID structure. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

PM brushless DC motor drive with a new power-converter topology

With the growing potential for widespread use of permanent magnet brushless DC motor (PMBDC) drives in many low-cost applications, such as HVAC, refrigerators, and freezers in houses and small-velocity servos in process industries, it has become important to minimize the cost. One obvious place for cost reduction is in the cost of the inverter and its associated controller. With that perspective, a novel application of the converter topology for the PMBDC known as “C dump” in switched reluctance motor drives is proposed in this paper. The advantages and disadvantages of this topology vis-a-vis the conventional three-phase H-bridge converter, are highlighted from the points of view of economy in switches, volt-ampere rating, associated controller cost, and packaging. Design considerations for the PMBDC are derived for use with the proposed converter topology. The operational and design characteristics of this converter-driven PMBDC drive are derived for four-quadrant performance. Guidelines for the design of the proposed topology are derived, and presented in the paper. Experimental results from a laboratory prototype are presented to validate the feasibility of the proposed PMBDC drive system     

采用DSP和FPGA直驱阀用音圈电机驱动控制系统

针对直驱阀用音圈电机控制系统的性能要求,以及现有电机驱动控制器存在的不足,提出一种基于浮点数字信号处理器(DSP)和现场可编程逻辑门阵列(FPGA)的驱动控制器结构方案.根据系统驱动控制所需功能以及DSP和FPGA各自的特点,进行了功能划分.其中:DSP作为主处理器,主要负责完成上电自检、系统初始化、通讯、以及位置环计...     

交流电机变频调速系统人机界面通信

人机界面是用户和机器联系的中介。文中所设计的人机界面主要应用于中型交流电机变频调速系统，在采用I2C总线（Inter IC Bus)通信协议的前提下，建立了一套以带有液晶显示LCD（Liquid Crystal Dispay)模块和键盘的单片机为“主”，以数字信号处理器DSP（Digital Signal Processor)为“从”的界面通信系统，实验证明，该 系统有较好的实时性和正确的数据传输，能实现对电机运行状态的监测、控制及故障排除，是一种较为可行的方案。