Chaos induced in Brushless DC Motor via current time-delayed feedback

Chaos in motor system is beneficial in some niche fields such as industrial mixing processes. In this paper, we investigate the issue of inducing chaos in Brushless DC Motor (BLDCM). Based on the differential-geometry control theory, a nonlinear function of current time-delayed control is derived. Analysis shows that the feedback scheme can induce the BLDCM operating in a stable regime to chaotic state across a large range of domain of control parameters, and if the values of control parameters α and β are set at an appropriate level, the variation of the time delay τ becomes insensitive to the occurrence of chaos, which is available in the compensation with inaccuracy of time-delay control.     

高压大功率变频器在太钢450m^2烧结主抽风机上的应用

本文从改造方案设计、变频器配置、改造实施过程以及变频器在烧结主抽风机上的成功应用,论述了太钢450m。烧结机主抽风机实施变频运行改造的技术过程。变频改造后,系统运行稳定、安全可靠、节能效果显著。     

长电缆传输引起的电机端口过电压的研究

电机与变频器通过长线电缆连接时．会在电机端口产生过电压,威胁电机的安全运行。本文在分析电机端口过电压产生机理的基础上,采用机侧滤波器抑制电机端口电压。利用MatIab／SimuIink建立仿真模型对其进行仿真分析,仿真结果验证了电机端口电压分析的正确性和所设计滤波器的有效性。     

Control for PWM ac chopper feeding nonlinear loads

This paper presents a novel robust control technique for PWM ac choppers with the ability to generate high quality sinusoidal waveforms with adjustable amplitudes over a wide range control. For this purpose a deadbeat-based digital controller has been developed to perform tight closed-loop control of the ac chopper. This controller is based on a generalized predictive control (GPC) approach. A dedicated control algorithm has been developed and implemented. The proposed controller presents the advantages of allowing a very fast transient response and compensating effectively for load disturbance and the effects of nonlinear loads. Computer simulations are performed to investigate the proposed controller performance. The simulation results show that the designed controller has a good dynamic behaviour, a good rejection of impact load disturbance, and is ;very robust. To evaluate the proposed approach an experimental prototype has been constructed. Experimental results under various loading conditions have demonstrated that the system performs well.     

未来电机驱动系统的关键技术

2005年9月在我国南京召开的第8届国际电机与系统会议（1CMS’2005）上，美国威斯康星-麦迪森（Wisconsin-Madison）大学的Robert D．Lorenz教授发表了题为“未来电机驱动的关键技术”一文。在该文中，R．D．Lorenz教授介绍了至今为止他所领导的研究小组的科研成果，提出了影响未来电机拖动系统的五项关键技术。本文介绍该文的主要内容和相关动向。     

电流反馈模式的电机驱动电路

传统电压控制模式的电机驱动电路系统频率都受电机的本征频率制约，其相位延迟会随负载的变化而变化。为了实现更高的系统频率，文章提出了一种电流反馈控制模式驱动电路。理论分析和仿真结果表明，这种控制模式的电机驱动电路解决了系统频率受电机负载本征频率制约的问题，相位的延迟也不随负载变化而变化。     

基于Matlab GUI的电机拖动辅助教学平台设计

交、直流电动机起动、调速、制动方法分析是《电机与拖动》课程教学中的重点问题,控制方式种类多,课堂教学主要是运用公式推导的理论分析方法,过程复杂且抽象难懂。利用Simulink建立交、直流电机拖动系统电气结构图仿真模型,GUI建立操作界面,二者交互链接开发电机拖动辅助教学平台,并以直流电机直接起动和电枢串电阻起动模块为例对设计过程中的关键技术进行了详细说明。该平台可实现原理说明、模型运行、参数设置、波形显示、结果分析等功能,对电机拖动原理以及效果的深入理解有很好的辅助作用。     

泵用永磁同步电动机变频调速控制系统设计

为了提高泵用永磁同步电机的工作效率,研制了一种永磁同步电机变频调速控制系统.该系统以80C196MC单片机为控制核心,采用简单的V/F变频控制方法达到较好的控制效果.针对该控制系统的硬件和软件实现进行了论述,并通过实验证明了该控制系统的可行性.     

Measurement of water by oven evaporation using a novel oven design. 2. Water in motor oils and motor oil additives

The measurement of water in lubricating oils is important because water accelerates the corrosion of metal parts and bearings in motors. Some of the additives added to lubricating oils to improve their performance react with the Karl Fischer reagent (KFR) causing a positive bias in the water measurement. A new oven evaporation technique for measuring water in oils has been developed that is automated, requires less sample handling, is easily calibrated, and is capable of measuring relatively small mass fractions of water (50 mg/kg sample). A series of motor oils was analyzed with the standard KFR, a reagent that detects interfering substances that reduce iodine, and the aldehyde–ketone reagent that does not detect substances that react with methanol and form water. The oil samples were heated to 107°C and then reheated to 160°C. At both temperatures, material was measured by both KFRs, but only zinc dithiophosphate released sulfur compounds that would react with the reagent that detects interfering substances. Mass fractions of between 20 and 70% of the volatile material released at either temperature were measured with the standard KFR but not with the aldehyde–ketone reagent. These results demonstrate that there are a number of sources of positive bias in the measurement of water in motor oils and that the standard KFR cannot be used to measure water in motor oils and motor oil additives. These results also indicate that some of the material reacts with methanol to form water. Finally, these results suggest that some of the material that is volatile at 160°C and not at 107°C may be water that is physically occluded or may be substances that react with diethyleneglycol monomethylether to produce water.     

基于中颖双核DSP的变频器应用

本文介绍基于中颖电子的双核DSP芯片在变频器上的应用,并给出了开环矢量变频器的实现方法,同时对变频器的关键性能指标做了演示和分析。