Control of Single Phase Induction Motor Using Forced-Commutated Electronic Switches and Free-Wheeling Paths

Single phase induction motors show better performance and have less cost if they are controlled using electronic switches instead of mechanical switches. This paper suggests a semiconductor-based method to start the motor and to control the speed and the direction of rotation. This is achieved by feeding the two stator windings of a split-single-phase motor via two forced-commutated solid-state devices. Meanwhile, each winding is shunted by a free-wheeling path that is controlled as well by a forced-commutated solid-state device. Therefore high starting torques and low starting currents are realized. Speed control is easily achieved at higher motor efficiency, compared with the case of controlling the motor using forced-commutated electronic switches without free-wheeling paths. This paper computes detailed performance characteristics of the motor employing the suggested method. For this purpose, the motor is represented in the dqo reference frame. Then, the performance is described by a developed state space mathematical model taking care of the discontinuities introduced by the electronic switches.     

A single phase induction motor drive with improved performance

This paper presents a new method to improve the efficiency and torque characteristics of a single phase induction motor. First, the mathematical model of the motor is analyzed. Next, a method which uses power electronic technology to improve the efficiency and starting torque of the motor is proposed. The starting capacitor and the centrifugal switch can be eliminated here. Only a running capacitor is used. A prototype system which consists of some simple hardware circuits and a TMS320C40 digital signal processor system has been implemented. Several experimental results can validate the simulated waveforms. This paper proposes a new direction in improving the performance of the single phase induction motor system.     

电动车开关磁阻电机驱动和保护控制策略研究

传统开关磁阻电机(SRM)起动时采用电流斩波控制(CCC),中高速阶段采用角度位置控制(APC)对转速进行调节。但在电动车领域的SRM驱动控制中,通常采用基于脉宽调制(PWM)控制的方式来实现电机的开环调速。在传统SRM控制方式的基础上,提出了一种动态斩波的起动方式以及一种PWM控制与APC控制相结合的中高速运行的综合控制策略,可确保电机在不同负载下平稳起动、瞬间提速和稳定运行。与此同时,对控制器保护环节中最为关键的过流保护和堵转保护进行了设计,提升了整个驱动系统的可靠性。为了验证所提驱动控制策略和保护方法的可行性,在以STM32F103处理器为控制核心的控制器和1台12/8结构电动车SRM上进行了系统的试验。试验结果表明在该控制算法下,电机能够快速起动和稳定运行,且能检测到故障并及时保护,证明了该算法的正确性。     

基于三电平逆变器的异步电机矢量控制研究

矢量控制使异步电机转子磁链与转矩解耦,可实现对转速、转矩和位置的精确控制,使异步电机具有与直流电机一样的控制特性。三电平逆变器比传统的两电平逆变器有更多的开关状态,有利于输出电压正弦化和向高压大容量发展。研究了基于三电平逆变器的异步电机矢量控制,在参考电压矢量的合成时,选择只包含PO状态的矢量作为起始矢量,既保持了中点电位的平衡,又消除了扇区切换时矢量突变问题。仿真结果表明电机动态、稳态性能优越。     

基于状态观测器的感应电机速度传感器故障诊断及容错控制

速度传感器是感应电机矢量控制系统的重要组成部分,当其出现故障时会严重影响系统的性能。设计感应电机矢量控制系统,并在此基础上实现了基于状态观测器的感应电机速度传感器故障诊断及速度传感器发生故障后的容错控制。在速度传感器正常时,状态观测器工作在故障诊断方式下;速度传感器发生故障后,该状态观测器工作在速度估计方式下,系统由原带速度传感器矢量控制方式平滑切换到无速度传感器矢量控制,从而实现速度传感器的容错控制。该设计的有效性在dSPACE实验平台上得到了验证。     

环形行波式超声电动机调相控制策略研究

文章分析了超声电动机调相调速的机理，提出了基于单片机控制的超声电动机调相调速系统，并且设计了相应的硬件电路和应用软件。实验表明，该系统具有代速起动平滑，线性度好，无需换向开关，调相调速范围宽等优点。另外该系统对谐振频率实施在线搜索跟踪，保证了超声电动机的优良性能不变，这是该系统的又一特点。     

基于全阶观测器的三电平逆变器异步电机无速度传感器矢量控制系统

采用全阶观测器的方法在三电平逆变器平台上实现了异步电机的无速度传感器矢量控制。针对观测器中增益矩阵选择困难的问题,采用解析推导的方法借助数学软件完整地得出了六组增益矩阵,并指出了采用不同状态变量时增益矩阵之间的联系。全阶观测器只需要两路直流母线电压和两路电机电流信号,可以在全速域范围内准确的观测磁链和转速,并成功的将观测得到的转速和磁链用于闭环矢量控制中。仿真和实验表明基于全阶观测器的矢量控制系统动静态性能良好,对电机参数变化具有较好的鲁棒性。采用预励磁的方法可以在减小起动电流的同时增大起动转矩,保证系统的低速稳定运行。     

18kW异步电机高压直流起动发电系统设计与实现

采用异步电机的起动/发电双功能电源系统将是战机、战车和汽车等移动电源系统的一个有竞争力的发展方向。结合18kW 270V高压直流起动/发电系统的研究工作,该文介绍了异步电机与变换器控制结合的起动/发电系统综合设计方案,通过两路三相变换器的功率开关的通断实现电机起动时Δ接法、发电时Y接法的转换运行,解决了起动时低压蓄电池供电和发电时输出高压的矛盾。分别阐述了异步电机起动运行和发电运行的控制策略,对比了异步电机"Y"、"Δ"2种接法下的转矩控制技术的特点,并简要介绍了宽转速范围内提供恒压电功率技术。这些关键技术使系统大大提高了发电的动静态品质和起动性能。最后给出系统仿真及样机试验结果。     

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.     

双馈感应电机反演控制系统的研究

文中应用反演控制理论设计了双馈感应电机转速跟踪控制的非线性控制器。该控制器利用了反演法的动、静特性优良,稳定性强的特点,可以良好地实现电机转速的跟踪控制。对于所提出的控制策略予以详细推导,并进行了仿真实验。仿真结果表明该控制策略能够实现双馈电机转矩和磁链的解耦,以及转速的有效跟踪,系统具有良好的动、静态性能和鲁棒性。     

A Microprocessor-Based Full Voltage Starting of Induction Motor with Switched Capacitors

ABSTRACT

Increasing concerns over the starting of induction motors with high starting torque requirements have prompted engineers to seek methods of starting with full voltage and switched capacitors. This method provides ample acceleration torque with minimum voltage disturbances on the main bus. A highly reliable microprocessor-based starter with high performance has been developed. The hardware and software architecture of this starter and its starting aspects are described. The programmable automation provided here allows a flexibility in algorithms which can be altered or expanded easily. The performance goals designed also include protection of induction motor against overload, phase loss, wrong phase sequence and severe over voltage due to self-excitation.     

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.     

ANALYSIS OF STATE FEEDBACK CONTROL OF CHOPPER DRIVEN SEPARATELY EXCITED D.C. MOTOR

ABSTRACT

Armature voltage control of d.c. motor speed to a set point in the face of large step torque changes can be treated as a regulation problem in linear system theory. By proper pole assignment, one can have complete control over the dynamics of the closed loop system. The control input comes out as a function of the states, motor speed and armature current respectively, and integral of the output (speed error). The paper deals with separately exicited d.c. motors fed from a thyrister chopper circuit controlled by the state feed back signal. Discontinuous mode of current conduction in the chopper gives rise to unwanted swings in the dynamic response of the system. The proposed approach models the system taking discontinuous mode of current conduction into account, obtains the feed-back constants and predicts the oscillations that may come into picture at low shaft torques. Also a time varying model in proposed and this gives the designer an insight into the working of the system and guides him in his choice of the feedback coefficients. The proposed regulation method has been tested on a laboratory model d.c. motor, and the experimental and the theoritically predicted response curves are found to be in agreement     

Time Domain Modeling and Digital Simulation of Variable-Frequency AC Motor Speed Control Using PLL Technique

A time domain model of the system has been developed and simulated on a digital computer. Starting transients as well as the steady-state speed control performance of the system have been studied. In order to improve the starting performance significantly, a modification has been incorporated in the control scheme for the starting period only. This modification avoids traditional osciflatory behavior of the induction motor and reduces undesired high current peaks (with high starting torque). To verify the validity of the time domain model and simulation method used, the computed results were compared with those obtained by the frequency domain method and found much closer to the reported test results. For efficient computation, the voltage equations for stator and rotor circuits of the motor were developed separately to avoid inversion of a time dependent matrix in every step of integration.     

永磁同步电机无位置传感器启动策略的改进

针对永磁同步电机,提出了一种基于滑模观测器的永磁同步电机(PMSM)无位置传感器启动控制方法.釆用电流闭环-速度开环的(I-F)定位,启动加速和速度-电流双闭环切换的控制方法.启动加速达到设定转速时,进入速度-电流双闭环的切换过程,采用K/cos2曲线对电机电流进行减小,进而减小滑模观测器估测的转子位置与给定坐标系位置...     

Microcomputer Control for Sensorless Brushless Motor

The microcomputer control of a brushless motor without a shaft position sensor is studied. A method which permits the determination of the permanent magnet rotor position by the back electromotive force (EMF) induced in the stator windings and the starting technique which uses the motor as a synchronous motor at standstill are explained. The motor voltage is chopped by commutator transistors to change the motor speed. The control system consists of a 4-b single-chip microcomputer and two quad-comparators.     

ANALYSIS OF POWER CONVERTER CONTROL USING NEURAL NETWORK AND RULE-BASED METHODS

ABSTRACT

Current-controlled voltage source inverters offer substantial advantages in improving motor system dynamics for high-performance ac drive systems. The controller switches follow a set of reference current waveforms. Fixed-band hysteresis and sinusoidal-band hysteresis controllers have been studied. The first part of this paper develops neural network and fuzzy logic based current-controlled voltage source inverters. The models and learning techniques have been investigated by simulation. The implementation of neural networks is described and simulation results are presented. In the second part of this paper, the new UPS (uninterruptible power supply) with fuzzy logic compensator is proposed. Proposed fuzzy logic compensator is used to prevent voltage drop from nonlinear load. The total harmonic distortion (THD) of proposed scheme is better than that of conventional deadbeat control method for linear and nonlinear load. In the third part of this paper, the application of fuzzy control to DC-DC converters operating at finite switching frequency is studied. Several control methods currently used for buck, boost and buck/boost converters are compared to the fuzzy converter control. Simulation results for several control methods are presented. The simulations show that the fuzzy control method has better dynamic performance and less steady state error.     

基于DSP异步电机无速度传感器直接转矩控制

基于模型参考自适应系统原理(Model Reference Self-Adapt System,简称MRAS)设计了一种新型的速度磁链自适应观测器,它以定子电流和定子磁链为状态变量,把磁链观测和速度辨识结合在一起,可以将定子磁链观测值直接应用于直接转矩控制算法中.定义了李亚普诺夫函数,根据其稳定性理论确定了速度自适应律.以TMS320F2812为核心构成控制器,实现异步电机无速度传感器直接转矩控制系统.实验结果证明,该系统具有较好的定子磁链和转速观测精度,能改善低速时磁链畸变程度和运行特性.     

双馈电机系统滑模变结构反演控制的研究

应用滑模变结构理论和反演控制方法设计了双馈感应电机的非线性控制器.该控制器结合反演法的动、静特性优良和滑模变结构控制鲁棒性强的优点,可以良好地实现电机转速的跟踪控制.针对电机转矩给定控制,提出了一种复合控制算法,有效地提高了系统动态性能和静态精度.对于所提出的控制策略予以详细推导,并在Matlab/simulink环境下进行了仿真试验.仿真结果表明,该控制策略能够实现双馈电机转速的有效跟踪,系统具有良好的动、静态性能和较强的鲁棒性.     

Induction motor drives for domestic appliances

The three-phase induction motor has been adopted for the drive described in this article. The target performance of the drive is based on the requirements for a commercial front-loading washing machine, with a load capacity of 11 lbs., which has an inner drum size of 460 mm. The production washing machine uses a universal motor drive, fed with AC from a phase-controlled triac. The motor rotates the drum through a belt drive, and the pulley ratio is 15:1. The aim is to design the induction motor drive to meet the torque speed needs. The base speed range is 1:14.5 for a wash speed of 55 r/min and a spin speed of 800 r/min. Increased spin speeds are desirable, requiring an extended speed range. Also, a slower “gentle wash” speed may be used. By applying variable frequency, variable voltage with slip control these requirements can be met by a high-speed induction motor operating with a suitable pulley ratio. The experimental drive comprises a high-speed three-phase induction motor fed by an inverter