新型异步电机在线监测和节能控制器的设计与实现

介绍了一种新型嵌入式异步电机在线监测与节能控制器。通过对异步电机定子工作电压电流的监测,分析电机工作效率,并对其实施PWM控制,从而实现对异步电机工作状态进行监测和节能控制。     

变频器供电的异步电机节能控制运行的研究进展

现有工程中广泛应用的异步电机变频控制具有算法简单、动态特性好的优点,但未顾及电机的节能控制运行。实际应用中异步电机经常处于轻载运行状态,效率非常低,这对缓解能源紧张和控制污染非常不利,因此引起了学术界和工程界的广泛关注。根据压频比的变化说明了电机节能运行的原理,介绍和分析了近几十年来异步电机节能控制研究中的常用实现方法及其优、缺点,同时指出工程应用中存在的问题和今后的研究趋势。     

单相异步电机动态节能控制装置的研制

目前，变负载运行是异步电机的主要工作状态，研究其动态节能方法和技术具有重要的现实意义。本文分析了不同负载情况下单相异步电机（Single Phase Induction Motor，简称SPIM）的动态损耗分布规律，由此利用电流向量图法，提出单相异步电机动态节能的有效控制途径；研制了一种新型的节能控制器。实验研究结果表明，该动态节能器与现有节电器相比，节能效果明显，可在实际中推广和应用。     

高效异步电机设计综述

高效异步电机设计对于实现电机系统节能减排意义重大,而提升异步电机效率,关键是在于降低电机各种损耗。论文首先从异步电机节能绕组、定转子槽配合、斜槽设计入手,梳理实现电机节能的措施及研究成果,再进而阐述异步电机多目标优化设计所涉及的若干关键技术,对比分析等效磁路法、有限元法及响应面法在异步电机多目标优化设计应用中的优缺点,再对高效异步电机设计亟需解决的关键技术予以总结和展望,旨在为高效异步电机设计提供借鉴和参考。     

应用于电动车的异步电机节能控制

纯电动车存在续航里程不足的问题,为改善此问题,提出了一种基于在线参数辨识的异步电机节能控制策略.出于降低电机稳态损耗的目的,在考虑了异步电机定子铁损的模型下,采用最小损耗模型对电机进行节能控制.同时设计了改进模型参考自适应系统(MRAS)观测器对电机转子时间常数和定子电阻进行在线辨识,减小参数变化对最小损耗控制的影响,使得损耗模型更为精准,节能效果更为理想.最后,通过仿真及实验对控制策略进行验证.结果表明,此算法在电机轻载高速时节能效果明显.     

考虑铁损的异步电机参数辨识实验研究

对基于损耗模型方法的异步电机效率优化控制方案而言,是否准确获知了控制策略中所需的电机参数,尤其是与异步电机铁损、铜损相关的电机参数将直接影响其节能效果。建立了考虑铁损的电机模型,使用改进遗传算法辨识了含铁损等效电阻在内的所有异步电机电气参数,辨识算法不需要假设定、转子漏感相等,更贴近真实情况。使用数据采集系统实施参数辨识实验保证已经安装在生产线上的电机仍能正常运转。实验结果表明所提出的参数辨识方案可提供足够精确的异步电机电气参数,使用参数辨识值估算的铁损、铜损与实测值有较高的吻合度,这使得基于损耗模型的异步电机效率优化控制获得最大限度的节能成为可能。     

基于异步电机效率优化的变频供水系统研究

研究了供水系统中驱动水泵的异步电机最大运行效率控制问题,对于整个社会的节能和减排具有重要意义.在研究异步电机最小损耗控制算法和流量、水压与水泵转速的关系基础上,建立了基于异步电机效率优化的变频供水闭环控制系统.与恒压频比控制进行了对比,仿真结果表明最小损耗控制算法在保证系统具有较好的动态响应的同时,显著提高了轻载时电机的运行效率,将其应用于供水系统中,将有利于提高系统的节能水平.     

异步电动机功率因数控制节能研究

建立了异步电机的多变量数学模型。以异步电动机节能运行为目的,分析功率因数与异步电动机参数及转差角频率Δωi间的关系,以此作为功率因数节能控制的依据,从而在变频调速中实施功率因数控制。     

异步电机降压启动控制线路的节能改进方案

分析了改进型异步电机Y—△降压启动控制线路工作原理，通过将交流接触器改为交流吸合．直流运行从而达到节能的目的。     

中小型电机技术发展趋势

简述了中小型电机中的交流异步电机、永磁同步电机(PMSM)、中小型发电机,以及电机控制、电机系统节能等主要技术的发展现状,并在此基础上分别对这些技术的发展趋势进行了分析和研究。     

基于全过程移动监督技术的感应电机定子绕组温度实时监测系统

随着物联网技术的发展,如何将物联网技术与非侵入式电力设备运行状态监测技术相结合成为当前研究热点之一。为了探索基于物联网技术的电气设备运行状态监测新模式,以感应电机定子绕组温度的非侵入式在线监测为出发点,首先提出了一种基于自适应法和最小二乘法的电机定子绕组温度辨识方法,并结合当前物联网技术的发展,设计了一种基于全过程监督技术的感应电机全寿命周期监督定子温度监测系统。以1台5.5 kW感应电机为例进行试验验证,结果表明该系统具有较强的鲁棒性。所提出的理念和技术可以为其他大型电力设备的状态监测提供重要参考和技术支撑。     

基于ARM单片机的异步电动机远程监测系统的设计

为了降低异步电动机监测系统成本和不增加电机转子的转动惯量,结合异步电动机动态速度估算、电磁转矩方程和可编程低通滤波器观测磁链,实现了无速度、无扭矩传感器的异步电动机转速和转矩的估算。系统的硬件设计采用性价比非常高的ARM单片机,12位串行A/D,以及通用电流电压传感器,大大提高了监测系统的性价比。为了实现监测系统与远程计算机之间的通信,该监测系统还设置了MC35I无线通信模块。试验结果验证了该异步电动机转矩和转速估算的有效性。     

基于单片机的异步电动机转矩转速检测

异步电机转速和电磁转矩的高精度估算是在异步电机动态速度估算和电磁转矩方程基础上采用校正补偿方法实现的.采用间断性转矩转速估算方法很好地解决了检测系统的实时性问题,检测系统没有采用专用的速度传感器和转矩传感器.为降低检测系统的成本,硬件设计采用的是普通的单片机及12位串行AD,通用的电压电流传感器等.仿真和实验结果证明采...     

An online stator winding resistance estimation technique for temperature monitoring of line-connected induction machines

A new technique for stator-resistance (R/sub s/)-based thermal monitoring of small line-connected induction machines is proposed in this paper. A simple device is developed for injecting a small DC signal into line-connected induction machines for estimation of R/sub s/. The proposed DC injection device is capable of intermittently injecting a controllable DC bias into the motor with very low power dissipation. Experimental results under motor startup, load variation, and abnormal cooling conditions verify that the proposed technique provides an accurate estimate of R/sub s/ that is capable of responding to the changes in the motor thermal characteristics, resulting in reliable thermal protection. The proposed technique is a very practical method for thermal protection of small line-connected induction machines that can be implemented with low cost in a motor condition monitoring system.     

Online condition monitoring of induction motors

Condition monitoring of induction motors is a process that may be used to great advantage in mining and other industrial applications. The early detection of motor winding deterioration prior to a complete failure provides an opportunity for maintenance to be performed on a scheduled routine without the loss of production time. Presented in this paper is a theoretical and experimental analysis of a voltage mismatch technique that may be used in operating situations to monitor the health of induction motor windings. It extends previous work in this area by demonstrating the robust nature of the monitoring process not only under conditions of power supply unbalance but also in situations where motor construction imperfections exist and mechanical loads are unpredictable. A suggested procedure for application of this condition monitoring process in industrial situations is also included.     

Current signature analysis to detect induction motor faults

Three-phase induction motors are the “workhorses” of industry and are the most widely used electrical machines. In an industrialized nation, they can typically consume between 40 to 50% of all the generated capacity of that country. This article focuses on the industrial application of motor current signature analysis (MCSA) to diagnose faults in three-phase induction motor drives. MCSA is a noninvasive, online monitoring technique for the diagnosis of problems in induction motors. Reliability-based maintenance (RBM) and condition-based maintenance (CBM) strategies are now widely used by industry, and health monitoring of electrical drives is a major feature in such programs     

基于小波包能量分析和信号融合的异步电机转子故障诊断

为提高异步电机转子故障诊断的可靠性,文中介绍了一种基于小波包能量分析和信号融合的异步电机转子故障诊断方法。采用定子电流信号和振动信号的频谱特征融合作为转子断条以及气隙偏心故障的诊断依据,首先对信号进行小波包分解,获得不同小波包频带节点下对应的能量分布,并与正常电机信号进行比较,进而对能量异常的信号频段进行小波包节点重构,最后通过快速傅里叶变换识别故障特征频率,诊断电机故障是否发生。通过仿真分析,验证了该方法的有效性和实用性,对于电机运行状态的准确监测具有重要意义。     

An Improved Method for Diagnosis of Induction Motor Load Mechanical Unbalance Fault Using Current Signal Analysis

Most induction motor problems are due to load instabilities. Load problems mainly influence on system mechanical properties. Therefore, it is preferred to detect these problems using mechanical sensors (e.g. accelerometer, velocity sensor, etc.). However, all motors and loads are not accessible, and remote monitoring of systems can be helpful. Motor current signature analysis (MCSA) is a remote monitoring method that has developed recent years. The aim of the current paper is to evaluate the ability of MCSA to detect centrifugal fan faults. It tries to show how to distinguish between unbalanced load and other types of induction motor unbalances based on MCSA method. In the current study, condition monitoring methods are improved by reformulating the current equations. These results come from a large research with the objective population of 60 induction motors in the alloy steel industry and here three case studies are used to check the theoretical results.     

Protection of squirrel-cage induction motor utilizing instantaneouspower and phase information

A method of protecting a squirrel-cage induction motor by checking its condition before starting and while running is presented. The check before running is made by successively connecting the windings of the motor to an impulse generator and analyzing the resulting current and voltage. The running motor is checked by monitoring the AC-component of the power signals in all three phases, the sum of which gives information about the motor condition. The method presented is very sensitive to short circuits in the motor wiring, interturn short circuit, ground faults, and phase failure, but is not sensitive to load changes and small deviations in the supply voltage