新型单绕组无轴承异步电机控制系统

研究了一种新型结构的单绕组无轴承异步电机,与传统的双绕组无轴承异步电机相比,采用一套绕组即可实现电机转子的悬浮和旋转。在分析单绕组无轴承异步电机新型结构和工作原理的基础上,推导出电机径向悬浮力和转矩部分的数学模型。针对单绕组无轴承异步电机的定子电流连接的复杂性,采用电流叠加控制方法,并设计基于气隙磁场定向控制的控制系统。在MATLAB/Simulink中建立控制系统的仿真模型进行仿真验证,并制作实验样机进行悬浮特性试验。结果表明,该方法控制的样机转速响应好、悬浮特性优良,从而验证了所提方法的正确性与有效性。     

转差频率矢量控制的电机调速系统设计与研究

鉴于直接转子磁场定向矢量控制系统较为复杂、磁链反馈信号不易获取等缺点,而转差频率矢量控制方法是按转子磁链定向的间接矢量控制系统,不需要进行磁通检测和坐标变换,并具有控制简单、控制精度高、具有良好的动、静态性能等特点。在分析其控制原理的基础上,应用Matlab／Simulink软件构建了转差频率矢量控制的异步电机调速系统仿真模型,并通过各模块间的参数配合调节与优化,对其进行了仿真分析。仿真结果验证了,采用转差频率矢量控制的调速系统具有良好的控制性能。     

基于免疫算法的导轨电车转差频率控制策略研究

为了优化感应电机传统转差频率控制的动态性能,基于某导轨电车提出了一种采用免疫算法的感应电机转差频率控制策略。根据免疫系统应答机理,类比出免疫算法,并利用免疫算法对转差频率进行实时调节,优化了因转差频率给定不合适导致控制系统的动态性能不佳的问题。实验结果验证了该控制方法的正确性和有效性。     

异步电动机转差率间接控制matlab仿真

本文对转差频率控制的异步电机矢量控制调速系统进行了研究分析和仿真。使用matlab中的仿真工具箱simufink为基于转差矢量控制的异步电动机变频调速系统建立了仿真模型,给出了仿真结果。     

考虑铁损补偿的异步电机最大效率矢量控制系统

异步电机铁损主要产生于定子铁心，铁损会使转子电流和转子磁通相互干扰，影响控制精度。本文把电机最大运行效率与考虑铁损的矢量控制有机结合，提出考虑铁损补偿的异步电机最大效率矢量控制新方法，对提案的控制系统进行数学建模，给出控制系统结构，并对该控制系统进行仿真研究，验证了该模型的正确性。     

一种用于优化感应电机电流环的新方法

在感应电机转差频率矢量控制系统中,电流环的性能对整个系统响应的快速性和准确性有着重要影响,而电流环在两轴直流旋转(d-q)坐标系下存在交叉耦合,并且随着电源角频率的增大耦合成分增大,导致电流环特性变差。为此提出一种新的优化方法,即在传统PI电流控制器的基础上,设定合理的模糊规则并选取合适的PI参数kI,kP,对电流系统进行优化。在Matlab的Simulink模块下对电流系统建模仿真,仿真结果表明,设计的控制方法有效地降低了两轴之间的相互扰动,提高了电流控制系统的动态特性,且新方法简单易行,有较强的鲁棒性。     

直线感应电机的转差频率控制仿真研究

本文介绍了直线感应电机的结构和工作原理，给出了把边端效应考虑在内的直线感应电机数学模型，对直线电机进行恒转差频率控制，仿真结果表明该控制系统的实现方法是可行的。     

基于MRAS的异步电机无速度传感器的矢量控制

由于电机定转子参数的变化,利用一般的转子磁链对转速进行估算,将导致不能得到准确的结果。这里采用积分型转子磁链的参考和可调模型构建出一个基于MRAS的异步电机无速度传感器的矢量控制模型。该模型提高了矢量控制系统的动态性能并利用MATLAB,sIMULINK进行了异步电机无速度传感器矢量控制系统的仿真,验证了文中所采用的模型参考自适应的速度估算方法的可行性以及对参数误差的鲁棒性。     

基于自适应遗传算法的模糊控制器应用研究

传统模糊控制器的设计主要依赖专家经验,存在较强的主观性和随意性,使得控制精度不高。为此,利用自适应遗传算法,优化设计了模糊控制器,并将其应用到三相异步电机的转差频率矢量调速系统中。仿真结果表明,控制效果好于PI控制。     

异步电机矢量控制系统的仿真建模与实现

异步电机矢量控制是在交流电机的双轴理论、机电能量转换和坐标变换理论的基础上发展起来的。为了实现对异步电动机磁场和转矩的解耦控制的目的;采用交流电机的磁场定向控制(即矢量控制)的方法;建立了一种在转子坐标系下异步电机的矢量控制系统仿真模型;仿真结果表明,基于矢量控制的方法能够实现对异步电机的解耦,即通过控制励磁电流分量和转矩电流分量的大小直接控制异步电机磁场和转矩,使交流异步电机获得和直流电机相媲美的控制性能。     

基于神经滑模变自抗扰控制的感应电机变频调速系统设计

基于强化感应电机变频调速系统的调速质量及响应速度的考量,文章设计出建立在神经滑模变自抗扰控制的感应电机变频调速系统。应用ADRC控制,在基础上提升了调速系统控制品质与控制精准性能。综合神经逆控制思想,创建起神经滑模变自抗扰控制器,减少系统的抖振现象,实现对感应电机调速系统转速、转矩、磁链等参数的最优化控制。     

Microprocessor-Based Optimal-Efficiency Drive of an Induction Motor

A method for improving the efficiency of a slightly loaded induction motor is suggested. It is based upon the optimal-efficiency slip tracking by adjusting the voltage to frequency ratio (V/f). It has adopted the converter-inverter fed induction motor drive system. All the control loops are implemented by the Z-80 microprocessor. By this method, 10 percent or more improvement is obtained at a quarter of the full load.     

A novel technique for optimal efficiency control of acurrent-source inverter-fed induction motor

A technique that optimizes flux level to improve the efficiency of an induction motor is discussed. When harmonics and saturation effects are considered, the slip of minimum loss, or optimal slip, depends on both the speed and the load torque. The measurements of speed and torque are achieved without conventional torque and speed sensors, using motor terminal quantities. The control strategy is divided into two stages. First, the optimal slip is searched by trial and error, and the results are tabulated in microprocessor memory. Then the motor is operated at optimal efficiency by simply tracking the optimal slip given in the table. Experimental results show good performance in energy saving and dynamic responses     

A high-performance sensorless indirect stator flux orientation control of induction motor drive

A new method for the implementation of a sensorless indirect stator-flux-oriented control (ISFOC) of induction motor drives with stator resistance tuning is proposed in this paper. The proposed method for the estimation of speed and stator resistance is based only on measurement of stator currents. The error of the measured q-axis current from its reference value feeds the proportional plus integral (PI) controller, the output of which is the estimated slip frequency. It is subtracted from the synchronous angular frequency, which is obtained from the output integral plus proportional (IP) rotor speed controller, to have the estimated rotor speed. For current regulation, this paper proposes a conventional PI controller with feedforward compensation terms in the synchronous frame. Owing to its advantages, an IP controller is used for rotor speed regulation. Stator resistance updating is based on the measured and reference d-axis stator current of an induction motor on d-q frame synchronously rotating with the stator flux vector. Experimental results for a 3-kW induction motor are presented and analyzed by using a dSpace system with DS1102 controller board based on the digital signal processor (DSP) TMS320C31. Digital simulation and experimental results are presented to show the improvement in performance of the proposed method.     

A Current Source Inverter Fed Induction Motor Drive with Power Factor Angle Control Using Microprocessor

This paper describes a method of adjusting the stator power factor angle for the control of an induction motor fed from a current source inverter (CSI) based on the concept of space vectors (or park vectors). It is shown that under steady state, if the torque angle is kept constant over the entire operating range, it has the advantage of keeping the slip frequency constant. This can be utilized to dispose of the speed feedback and simplify the control scheme for the drive, such that the stator voltage integral zero crossings alone can be used as a feedback for deciding the triggering instants of the CSI thyristors under stable operation of the system. A closed-loop control strategy is developed for the drive based on this principle, using a microprocessor-based control system and is implemented on a laboratory prototype CSI fed induction motor drive.     

Stator flux controlled V/f PWM inverter withidentification of IM parameters [induction motors]

A V/f PWM inverter control algorithm based on controlling the stator flux vector of an induction motor is presented. The algorithm permits an automatic boost of inverter voltage in such a way that the stator flux magnitude is kept constant. The voltage autoboost method is based on knowledge of the IM equivalent circuit parameters and given load characteristics. An offline auto measurement of the equivalent circuit parameters using a PWM inverter is described. The technique consists of performing the no-load and single-phase tests when the motor is connected to the inverter. The complete control system has been constructed and tested and the experimental results have been found satisfactory. The proposed method has achieved a considerable improvement of IM torque-speed characteristics under optimal slip frequency operation     

无模型控制方法在异步电动机控制中的仿真研究

在异步电动机的转差频率矢量控制中,其控制不需要复杂的磁通检测,且运算和控制简单,因而在基频以下的调速系统中得到较多的应用。但该系统存在比较明显的缺陷。基于此,本文设计了一种无模型自适应控制器,将该控制器引入原系统,与原系统构成前馈补偿。仿真试验表明,该方法有效减小了转矩脉动,改善了定子电流波形,具有良好的动、静态性能。     

电动汽车用双向DC-DC变换器最优效率控制研究

针对电动汽车复合能源系统中隔离双向DC-DC变换器采用传统单移相控制峰值电流和功率损耗过大的缺陷,提出一种基于双重移相控制的最优效率控制策略。首先分析了双重移相控制工作原理,建立了隔离双向DC-DC变换器功率损耗模型,然后分析推导了隔离双向DC-DC变换器功率损耗最小的条件及最优效率控制的实现方案,使双向DC-DC变换器工作在功率损耗最小状态,从而使系统效率实现最大化。最后通过实验验证了最优效率控制的正确性和优越性。     

Efficiency Optimization Control of Single-Phase Induction Motor Drives

The recent rising of oil prices and global warming crises increasingly support the ongoing practice of loss minimization control of electric motors including single-phase induction ones as the most used motors. Therefore, the tendency toward using variable-speed drives (VSDs) to save energy by adjusting motor speed is seen, but on account of increasing motor loss in nonrated conditions, an efficiency control system can improve energy saving even more. In this paper, after carrying out a detailed motor efficiency analysis, an appropriate method for motor efficiency maximization control, combined with a VSD, is presented and implemented. Experimental results of the implemented system validate the proposed method.     

Decoupled control of thrust and normal force in a double-layer single-sided linear induction motor

In this paper, a modified force decoupling method for improved servo control of a magnetically suspended double-layer single-sided linear induction motor (LIM) is presented. In this study, the primary is magnetically suspended under and moved along the double-layer secondary which consists of an aluminum plate with a back-iron. In order to decoupled the normal and thrust force, analytical expressions for the forces as function of the slip frequency and the primary current are obtained by curve fitting on steady-state FEM results. From these steady-state force models, the required current amplitude and slip frequency are solved for given force setpoints. The setpoints are generated by a position controller which is designed based on a dynamical model of the LIM. The dynamical model is estimated by injecting noise into a transient FE-model and measurements. Transient FEM simulations and measurements show the effectiveness of the proposed controller and decoupling method when they are used to magnetically suspend and position the LIM.