Understanding the TEWAC Motor

The TEWAC (totally enclosed water-air cooled) induction motor is not a new development. Such machines have long been common in Europe. Their usage in the United States has been less frequent, but growing emphasis on noise reduction is creating new interest in the inherently quiet TEWAC machine. Review of current specifications and orders shows that many motor users, inexperienced in TEWAC applications, are uncertain how to deal with possible cooler leakage, water flow control and monitoring, effects of high water temperature, motor rating versus ambient temperature, water chemistry, and cooler construction and mounting. Each of these matters is discussed in detail.     

A DC Motor Control System for Electric Vehicle Drive

A control system of a dc separately excited motor for electric vehicle drive is described. The armature of the motor is controlled by a thyristor chopper, whereas the field is regulated by a highfrequency transistor chopper. The control scheme combines the advantages of both series and shunt motors and permits maximum possible acceleration within the transient thermal ratings of the motor. In addition, motor torque becomes smoother under all operating conditions. A complete drive system has been formulated, designed, and analyzed, and performances have been evaluated on a hybrid computer. At present, the breadboard of the drive system is being tested in the laboratory.     

THYRISTOR CONVERTER-FED SYNCHRONOUS MOTOR DRIVE

ABSTRACT

The development, design and construction of a variable speed drive using a synchronous motor is described in this paper. At first, the operation of motor with a current-fed, motor e. m. f. commutated inverter is explained. The working of control circuitry is explained next with the aid of logic and functional blocks. The power circuit, comprising the converter, inverter and motor has been reduced to simple blocks so that the controller design by hand computations becomes possible. It has also been shown that the digital simulation based on simplified block diagram is accurate enough for obtaining the responses of the system to step changes in speed reference and load on motor.     

Sensorless rotor position estimation at standstill of cylindrical brushless dc motors using opened phase voltage change caused by eddy currents

A rotor position estimation of a cylindrical brushless dc motor at standstill has been difficult to obtain. Therefore, torque control of a motor has been difficult at starting of the motor, and realization of the position estimation at standstill has been sought. This paper proposes a simple processing of a rotor for which nonmagnetic materials are pasted on the rotor surface. This processing generates an eddy current on nonmagnetic materials and causes an opened phase voltage change according to rotor position. The experimental results using a microcomputer show that it is possible to estimate rotor position of the cylindrical motor despite a standstill by using the opened phase voltage change. ©�1998 Scripta Technica, Electr Eng Jpn, 126(1): 52–60, 1999     

直流电机数字调速软件的实现

直流电机调速多采用模拟控制,虽然速度响应快,但电路复杂,不易调试。随着高速处理器的问世,数字软件控制已经逐步取代了传统的模拟控制。基于此,本文充分利用DSP芯片的高速处理运算功能,通过软件实现直流电机的数字控制。传统的调速方法是通过模拟PID控制,响应速度快,但是动态适时调整较差,而数字软件的控制方法能够实现电机转速的动态调整,并且能够实时控制电机的转速,控制精确高。文章详细介绍了软件算法编程控制方法,实验结果表明,该数字软件实现直流电机调速在负载突增和突减时具有很好的控制性能,能达到相当高的控制精度。     

An asynchronized converter-fed motor and its model

Results of theoretical and experimental studies of an asynchronized converter-fed motor (ACFM) are presented. A proposed version of a converter-fed motor is designed on the basis of an asynchronous motor with a phase-wound rotor based on a voltage inverter with IGBT modules as power switches. A signal from the current sensor to the microintegrated control system further shifts the driving pulse toward an ordered constant angle. These modifications improve energy performance and increase the switching capacity of the inverter by adjusting the delay angle of the power modules. An ACFM model has been developed on the basis of presented equations. It is useful to obtain the ACFM’s stator and rotor transfer function and to determine the controlled variables and control and disturbance influences. The proposed mathematical model makes it possible to investigate transient processes in an electric machine during starting up to speed, as well as under changes in shaft load.     

步进电机的单片机控制设计分析

步进电机是一种将脉冲信号转换为相应角位移的执行元件,在工业控制领域应用广泛。本文介绍了步进电机的控制原理,详细论述了采用单片机的控制方法,并以35BY48L02步进电机为例,分析设计了单片机的硬件接口电路及步进电机的软件控制方法。该设计具有通用性,对于不同步进电机,可以通过修改相应的电路及相关程序实现,提高了系统控制的灵活性。     

Sensorless-control of the synchronous reluctance motor

In this paper a sensorless closed-loop speed control for the synchronous reluctance motor is presented. The sensorless control is based on the torque vector control algorithm. It has been implemented using a high-speed digital processor DSP96002. Experimental results for a 120 W axially-laminated synchronous reluctance motor are presented and compared with operation with a speed sensor and simulations. A base speed range of 400-1500 RPM has been achieved. The top speed was extended to 2750 RPM using flux-weakening. The drive can be applied a full-load step-change within this speed range without losing synchronism     

矩阵变换器供电的异步电动机DTC-SVM控制

提出一种由矩阵变换器供电的异步电机直接转矩控制-空间矢量调制(DTC-SVM)方法.该控制系统结构简单,转矩脉动小,输入功率因数为1.通过使用矩阵变换器空间矢量调制技术及异步电机的直接转矩控制技术,两种控制技术的优点得到了综合.用MATLAB软件对该控制系统进行了仿真测试,由仿真的矩阵变换器的输入、输出波形及异步电动机的速度、转矩波形证实了控制策略是有效可行的,系统具有良好的动态性能.     

Inertia-lowering control of induction motor

There are many requests for selecting freely the moment of inertia, even though the moment of inertia is determined by the materials, structure, shape, and size of the motors. From the standpoint of control, reducing the moment of inertia will make it possible to construct well-controlled drive systems and expand the applications in which a motor may be used to replace another nonelectric machine. An “inertia-lowering control” system has been developed that uses disturbance observer to reduce inertia. To realize this control system with vector-controlled induction motors, the equations and machine constants needed for designing the systems have been clarified. A digital signal processor and a microprocessor were adopted for induction motor control, and good results were obtained through the experiments.     

QUICK AND PRECISE POSITION CONTROL OF ULTRASONIC MOTORS WITH TWO CONTROL INPUTS

ABSTRACT

Ultrasonic motor (USM) has an excellent performance and many useful features. Since this motor is superior in holding torque and high response characteristic, it has been expected to use as position servomotor for small motors.

There have been reported some mathematical models of the ultrasonic motor. however, these models are too complex to apply for control of the motor. Therefore position controllers based on PI control or fuzzy control have been proposed in recent years. It is difficult to control the ultrasonic motor with high-performance using such controllers, thus simple and convenient mathematical model is necessary for precise control.

This paper presents a new position control scheme of ultrasonic motor, it consists of a PI controller and an adaptive controller which compensates the speed characteristic variations with online parameter identification. Moreover, this system controls both driving frequency and phase difference in order to achieve a quick and precise position control. The effectiveness of proposed control.scheme is demonstrated by experiments.     

Instantaneous speed detection with parameter identification for ACservo systems

Two methods adopting advanced control technology in order to improve the performance of AC servo systems are described. The first method is the detection of instantaneous speed using an observer. This method provides good response in speed control because it is possible to detect exactly the speed without detection dead time over a wide range of speeds. The second method is the identification of the mechanical inertia time corresponding to motor and load based on the model reference adaptive control system. This method enables the instantaneous speed detection to be applied to systems in which the mechanical inertia time is unknown. Moreover, it can realize the automatic adjustment of a speed controller using the result of identification. The effectiveness of these methods has been confirmed by experimentation. The experimental system is composed of a digital controller with a digital signal processor, a PWM inverter, and a permanent magnet motor     

步进电机高分辨率细分控制函数发生器的研究

提出了一种新的步进电机细分控制函数的生成算法——插补法,该方法用圆弧插补技术产生高分辨率的细分控制函数,并用笔者提出的加权补偿法对其进行动态修正,解决了不同步进电机的恒力矩均匀细分的难题.该算法简单很有实用价值.     

基于saber的感应电机控制系统仿真研究

采用交-直-交变换器对鼠笼式感应电机的电动状态进行控制,由于交-直-交变换器中间直流环节使AC/DC和DC/AC模块相互独立,AC/DC采用SPWM高频整流矢量控制,实现整流的高功率因数,DC/AC采用SVPWM空间矢量控制,以提高直流环节电压利用率,从而使感应电机获得优良的调速性能,在saber软件中对以上控制策略进行了仿真研究,仿真时采用Newton-Laphson算法及变步长仿真,仿真结果较真实的反映了感应电机的运行状况,仿真系统收敛性强,对今后研究感应电机的控制系统提供了有益参考。     

开关磁阻电动机直接转矩控制的研究

直接转矩控制(DTC)在交流电机驱动系统中是一种较完善的控制理论.事实证明它能很容易的控制电机的转矩和转速,并能减小转矩脉动.但是以前通常认为交流DTC方案不能应用于非正弦激励的SR电机.将直接转矩应用到开关磁阻电机的控制上,解决了SR电机转矩脉动问题.仿真及实验结果表明,这种控制策略不但可以有效地抑制SRM转矩脉动,同时控制简单、实时实现时只用低成本的微处理器即可.     

Triac Speed Control of Three-Phase Induction Motor with Phase-Locked Loop Regulation

The speed control of a three-phase squirrel cage induction motor by employing triacs in the lines which operate in the normal phase control mode is described. The inherent limitation of low circuit commutated (dv/dt), which makes the triac circuit somewhat unreliable, has been overcome by suitably designing the snubber circuit. The closed-loop speed regulation of the system is then investigated by employing digital phase-locked loop scheme. Compared to the conventional method with antiparallel SCR's and analog servo, the present scheme is somewhat simpler, more economical, and extreme precision in speed control is possible. A complete model of the speed control system has been designed and experimentally evaluated in the laboratory.     

基于高频电压信号注入凸极PMSM无传感器控制的仿真研究

永磁同步电机以其体积小、效率高、可靠性好以及对环境的适应性强等诸多优点,在各种高性能驱动系统中得到广泛应用.无传感器永磁同步电机控制技术具有成本低、体积小,可靠性高等优点,是当前永磁同步电机控制技术领域的研究热点之一.该文对基于高频信号注入法进行永磁同步电机无传感器控制技术的基本原理进行论述,并采用滤波方法得到转子位置...     

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     

隐极同步电动机转矩可控性与解偶性分析

交交变频同步电动机矢量控制系统已广泛应用于轧钢机主传动,对其控制原理的研究具有重要的意义.依据隐极同步电动机dq轴系和气隙磁链定向的数学模型,对转矩的解偶性和可控性进行了分析,还对阻尼绕组的影响进行了分析,认为阻尼绕组有助于减少动态速降并可稳定动态过渡过程,无阻尼绕组传动系统的转矩解偶、控制方便,但动态时可能发生震荡.     

A field orientation scheme for current-fed induction motor drivesbased on the torque angle closed-loop control

A novel field orientation scheme for current-fed induction motor drives is presented. The scheme is based on the closed-loop control of the torque angle and has the merits of being simple in implementation and insensitive to rotor resistance variations. The limits of previous field orientation schemes are reviewed. The torque angle control scheme is then formulated, and its application to induction motor (IM) drives fed by either current source inverters or current-controlled PWM inverters is illustrated. As an example, a current source inverter induction motor drive incorporating the scheme is designed, and its performance, which has been tested by simulation, is given