Structure and operation mechanism of a friction-type piezoelectric motor utilizing the principle of strain-wave gearing

This paper proposes a new type of motor which utilizes multilayer piezoelectric devices for electromechanical power conversion and the mechanism of the strain-wave gearing to generate traveling waves and motive force. The construction and basic operation of the motor are described. The motor can be operated in variable frequency because piezodevices are operated in the nonresonant mode. Approximate analysis is performed to clarify the operating mechanism of the motor and to obtain characteristics on the rotational speed in the case of no-load. Experimental results on rotational speed of the prototype motor made of metals except for the piezoelectric devices also are presented, which verifies the feasibility of the proposed motor.     

新型共振腔式声波清灰装置在“W”型火焰锅炉上的应用

针对存在的折焰角斜坡区域积灰严重,频繁发生运行中因积灰垮塌造成的锅炉燃烧不稳甚至灭火的情况,在该区域加装声波清灰装置,配合燃烧调整和蒸汽吹灰器的使用,基本解决了积灰严重和垮塌造成的燃烧不稳和灭火的问题。     

永磁型无轴承电机无径向位移传感器运行研究

在分析悬浮绕组电感与转子径向位移线性关系的基础上,针对永磁型无轴承电机无径向位移传感器运行的需要,分析了一种基于悬浮绕组高频信号注入的转子径向位移估算自检测方法,讨论了利用高频信号注入、悬浮绕组差分电压提取及转子径向位移跟踪观测器设计等位移检测原理和实现技术,并应用这种位移检测方法建立了永磁型无轴承电机无径向位移传感器控制系统.仿真研究表明,该位移自检测方法能在永磁型无轴承电机全速范围内准确地观测出转子的径向位移,实现无径向位移传感器方式的稳定悬浮运行.     

变频器驱动的新型异步电动机的分析

随着变频调速技术的深入发展 ,用于变频器驱动的电动机也在朝着变频器驱动专用电动机方向变化。本文介绍了用于变频器驱动的中等容量新型异步电动机的技术参数和规格 ,对其结构、性能进行了分析 ,并与一般异步电动机作了一系列比较。     

Control and operation of a new 8/6-pole doubly salient permanent-magnet motor drive

This paper proposes a new 8/6-pole doubly salient permanent-magnet (DSPM) motor drive, which offers the advantages of higher power density, higher efficiency, and wider speed range. The corresponding control and operation of the motor drive are presented. A variable proportional-integral (PI) controller combined with bang-bang control for the DSPM motor drive is developed. Two operation modes, namely, four-phase and two-phase operation modes, are proposed for the 8/6-pole DSPM motor drive. The drive system is implemented and tested. The results show that the developed control scheme can operate the DSPM motor properly, and the DSPM motor drive offers high efficiency over wide power range and good dynamic performance. Furthermore, the two-phase operation mode of the 8/6-pole DSPM motor offers the possibility of eliminating the torque ripple of the motor drive.     

新型大容量调相机原理及运行控制

新型大容量调相机具备吸收或发出大量无功且无功数值能够快速连续调节的特性,可为电网提供大容量无功备用,改善电网无功平衡状况,有效提高电网稳定性、运行性能及效益,且在电网系统故障时可提供有效的电压支撑.调相机的控制策略贯穿其整个运行过程,直接影响其运行的安全性、可靠性及经济性.本文分析了其控制原理及欠励运行、过励运行阶段模...     

一种新型一体化高压计量检定装置的研制

提出了一种兼顾单相、三相电压互感器和电流互感器以及电能表的一体化高压计量检定装置,具体提供了该检定装置的设计理念和构建的技术路线,并全面分析了该其测量不确定度来源。该一体化高压计量检定装置的研制成功,对解决国网公司最新确立的一、二次融合技术方案所需的电子式互感器、高压计量模块的检定具有重要意义。     

Principle and basic characteristics of linear synchronous motor with half‐wave rectified self excitation

This paper presents the principle and basic characteristics of a novel linear synchronous motor based on “half‐wave rectified self excitation principle.” The field winding is short circuited through a diode and the armature winding consists of conventional three‐phase windings. If the amplitude of the balance three‐phase currents is modulated by an alternating wave with bias frequency, the produced magnetomotive force pulsates at the bias frequency and moves at the synchronous velocity. This pulsating magnetomotive force induces the electromotive force with a bias frequency in the field winding. The field excitation is obtained by rectifying the electromotive force with the diode in the field winding. In this paper, the authors design and build an experimental machine and confirm its basic characteristics. They also deduce the performance equations and investigate the thrust ripple reduction. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(1): 82–90, 2008; Published online in Wiley InterScience ( www. interscience.wiley.com ). DOI 10.1002/eej.20684     

A new control strategy for optimum-efficiency operation of asynchronous reluctance motor

In this paper, an optimum-efficiency control scheme of synchronous reluctance motors is presented. There exists a variety of combinations of d- and q-axis current which provides a specific motor torque. The objective of the optimum-efficiency controller is to seek a combination of d- and q-axis current components, which provides minimum input power, that is, minimum losses at a certain operating point in steady state. A small amount of perturbation is added to the d-axis current reference for the purpose of searching a minimum input power operating point     

一种新型电子延时模块在异步电动机起动中的应用

介绍三相异步电动机起动时，通常按照一定的时序接通或关断2到3台接触器来实现电动机的起动。控制时序是确保电动机可靠起动的关键因素，而延时模块是实现控制时序核心部件之一。针对当前延时模块中所存在的不足，现设计了一种新型低成本、高精度、高可靠性的电子式延时模块并将其应用于异步电动机的起动中，取得了良好的效果。     

行波接触型超声波电机特性与控制研究

行波接触型超声波电机的工作原理与电磁型电机的工作原理截然不同,本文对其控制系统各组成部分作了分析,给出了控制器输出波形;并对行波接触型超声波电机定、转子之间的摩擦传动进行了研究,提出了电机效率计算方法,对机械特性与效率曲线进行了计算,计算结果与实验测试结果相符合。     

引信用压电式射流发电机的原理与研究

对一种新型引信用压电式射流发电机的工作原理进行了分析研究.指出压电片的基频固有频率与谐振腔的固有频率相同时发生谐振现象,可以提高发电机的电能输出,并推导了压电片及谐振腔的固有频率公式,为该发电机的设计提供了理论依据.压电式射流发电机具有可连续供电、响应速度快、体积小、电磁兼容性好等优点,其作为引信用环境能源具有宽阔的使用前景和利用价值.     

新型电动式接地极安装装置的研制

定期测量变电站接地网接地阻抗是保证电力系统安全稳定运行的重要技术手段之一,目前常用的方法为电压-电流表三极法,测量过程中需要使用锤头人工锤击安装电流极和电压极辅助进行测量,存在安装时间长、拆除困难、安全风险高、单根电流极接地电阻大等弊端。针对上述问题,研制了一款基于压力感应的新型电动式接地极安装装置,配套设置中空注液腔的接地极,实现人工安装方式的电力替代,单人即可操作,遇到障碍时可自感应破除障碍,安装完毕后可实现降阻剂打压降阻,提高了变电站接地网接地阻抗测试的工作效率和安全性。     

感应电机的新型神经网络广义逆系统解耦控制

针对感应电机这一多变量、强耦合系统,提出了一种新型神经网络广义逆系统解耦控制方法,给出了新型广义逆系统的存在性证明.它与感应电机复合,将转子磁链与转速的解耦成两个独立的伪线性子系统,并且可以随时通过调整反馈参数改变两个伪线性子系统的配置极点,为控制器的设计提供了便利.仿真结果表明,通过合理的选择配置极点和控制器参数,整个控制系统对电机参数变化和负载扰动有较强的鲁棒性和动态性能.     

Constructions and characteristics of a tiny piezoelectric linear motor using radial mode vibrations

A tiny ultrasonic linear motor with a structure has been developed, and various shaft materials were tested in the motor in order to improve its dynamic properties. We found that the shaft material has direct influence on efficiency, reliability and quality of the motors and their dynamic properties and is crucial to the achievement of high motor performance. The use of shafts of various materials such as stainless steel, stainless steels coated with DLC (Diamond Like Carbon) and PTFE (Teflon), a Pyrex, and a graphite, can make it possible to improve dynamic properties of the motors over a wide range of tribological conditions. In a motor with a stainless steel shaft coated with DLC driven at 44 kHz, its velocity was 4 mm/s with a force of 75 mN. When a motor used the Pyrex shaft was used a force of 110 mN was attained at 51 kHz. Thus the maximum force produced by a motor with a graphite shaft is estimated to be 120 mN with a velocity of 8 mm/s. We found that graphite has the appropriate surface conditions and directional texture to promote the linear motion of the moving element. Finally, the use of a cap resulted in significant improvements in the stability of the motor’s operation. Motor with graphite and Pyrex shafts were found to exhibit very stable operation and improved dynamic characteristics.     

一种新型的消弧线圈自动跟踪补偿装置

准确地计算电容电流是消弧线圈自动跟踪补偿装置应用基础。采用一种简单实用的带阻尼电阻的消弧线圈电容电流计算方法,只需通过投切消弧线圈接地系统的阻尼电阻便可求解电容电流。研发了基于多核控制器的自动跟踪补偿装置,多核分工协调完成自动跟踪补偿装置的复杂任务,避免了传统补偿装置需要多个控制器的繁琐设计。具体介绍了各个控制核的功能,并搭建了消弧线圈自动跟踪补偿装置IEC61850模型。实验测试所研发装置满足IEC61850一致性要求,而且装置的电容电流补偿具有良好的精度。     

一种具有储能功能的新型电气制动装置研究

基于超级电容储能原理,具有储能功能的水轮机组电气制动装置,即超级电容储能制动装置(Super Capacitor energy storage Brake Device,SCBD),SCBD可以在发电机故障情况下甩负荷时用于调节发电机转子动能量,以提高机组暂态运行的稳定性,还可在发电机正常停机过程中用于制动发电机转子,辅助水轮机组快速停机。为了验证SCBD在水轮机组暂态运行中所起的作用,采用微分代数多指标非线性控制(Differential Algebraic Multi-index Nonlinear Control,DAMNC)方法对水轮机励磁系统与SCBD进行非线性协调控制设计。仿真结果表明:SCBD具有良好的电气制动效果,明显提高了系统暂态稳定性,动态、静态性能均能得到很好协调。     

行波接触型超声波电机定子齿对电机性能的影响

本文对行波接触型超声波电机定子振动情况进行了分析，得到定子振动的固有频率和幅频特性，阐述了电机中定子齿的设置对定子振动的作用。针对三种不同的定子环模型，分别讨论了定子齿对固有频率、振幅及电机转速的影响，计算结果与实验测试结果相符合。     

新型电力检修作业地线装置的研究

针对目前电力系统检修工作中挂、拆接地线存在的安全问题,在分析接地线状态在线监测必要性的基础上,介绍了一种新型电力检修作业地线装置的构成和硬件电路的实现.并根据电力检修作业时现场的实际情况,采用了基于全球移动通信系统GSM(Global System for Mobile Communication)短消息技术的接地线在线监测装置的设计方案,并完成了装置的硬件设计和软件设计.     

超声波电机定子振动模型的一维解析

在简述了行波型超声波电机工作原理的基础上,重点讨论了该类型电机定子的一维振动模型,由此对超声波电机的振动特性进行了数值计算。最后对所计算的样机进行了实验,并将其与数值计算结果进行了比较,证实了所提方案的准确性。