罩极电动机节能降耗

短路环沉在定子的端面之下，线架底部的高度可以减小到1．5mm。这样，线圈每匝的周长减少了6mm，从而减少了端部用铜材；同时短路环的长度也有所减短，又节省了铜材。     

Power characteristics of a new kind of air‐powered vehicle

Nowadays, hydropneumatic transformer (short for HP transformer) is widely used as the main part of the power system of air‐powered vehicles to pump pressurized hydraulic oil from compressed air with a lower pressure. In this paper, the power system of a new kind of air‐powered vehicle is built using HP transformer as the pneumatic pressure boosting structure and hydraulic motor as the power unit. To set a foundation for the optimization of the power system, the dynamic characteristics are analyzed by building the mathematic model and setting up the experimental station. What is more, the affection of several key structure parameters is researched. Through experimental and simulation study, it can be concluded that, firstly, the mathematical model is proved to be effective; secondly, increasing the area ratio of the pistons would improve the output power as well as reduce the system efficiency, and we choose 6 for a balanced choice; thirdly, the output power and the system efficiency will rise with a larger oil discharge orifice; lastly, the increasing pressure of the input air will raise the power and meanwhile decrease the efficiency. In this system, the efficiency will remain above 30%. This research can be referred to in the design of the power system of air‐powered vehicle and the study on the optimization of the dynamic characteristics. Copyright © 2016 John Wiley & Sons, Ltd.     

阀室引压管放电烧蚀失效分析

近年来,我国油气管道沿线阀室遭受的交、直流电干扰日益严重,由此引发的阀室引压管放电烧蚀问题逐渐凸显,亟需开展相关研究来弄清阀室引压管放电烧蚀的规律和机制。为此,以西气东输天然气管道某阀室引压管的放电烧蚀为例,搭建了实验室放电烧蚀平台,采用实验室模拟实验、微观分析以及现场测试相结合的方法,对该阀室引压管放电烧蚀的规律和机制进行了研究。结果表明:(1)当两根引压管间的交直流电压差大于4 V且存在接触引弧时便可以观察到明显的放电现象;(2)随着引压管间电压差和回路电流的增大,其能量升高,引压管放电烧蚀越严重;(3)直流放电烧蚀情况下阴、阳极呈现出明显不同的烧蚀形貌,阳极区烧蚀更加严重,其烧蚀坑呈现凹坑且烧蚀坑中没有明显的烧蚀产物沉积,阴极区烧蚀深度较浅,表面沉积一层烧蚀产物,而交流放电烧蚀情况下阴阳极烧蚀区域形貌基本一致,无明显差异。结论认为:该阀室的引压管放电现象是一种弧光放电,可以通过固定引压管、增大引压管间距以及阀室的交直流排流等措施来避免该现象的发生。     

三相交流异步电机的磁势及电磁转矩的空间分布

三相交流异步电动机绕组的磁势是电动机运行的基础。文章依据理论分析,做出了磁势、磁场及电磁转矩分布曲线。磁势及电磁转矩曲线能形象、直观地反映交流异步电动机磁势、磁场及转矩间的关系,对进一步理解电动机的原理、公式、特性提供帮助。     

Conductive and flexible multi-walled carbon nanotube/polydimethylsiloxane composites made with naphthalene/toluene mixture

Conventional conductive materials face challenges when utilizing them for flexible and wearable electronics and soft robotics. Carbon nanotube/polydimethylsiloxane (CNT/PDMS) composites are a promising alternative to the conventional hard conductors because they are light and can realize large deformation. To date, well dispersion of CNTs into PDMS to increase conductivity while maintaining flexibility remains challenging. We aimed at developing highly electrically conductive and flexible multi-walled carbon nanotube/PDMS (MWCNT/PDMS) composites. To this end, we proposed a method to enhance the dispersion of MWCNTs into PDMS using naphthalene and toluene. Our results showed that the addition of naphthalene and toluene into the composites improved dispersion of the MWCNTs and increased the direct current (DC) electrical conductivity. We also found that the morphology of primary aggregates of the MWCNTs influenced the DC electrical conductivity of the composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48167.     

A Real-Time Application of Modified Inductor Coupled KY Converter Topology in Speed Control of E-Bikes

Abstract

Congested road network and traffic jam lead to vehicle idling and fuel wastage. An E-bike which is a solution to this is often available with Thumb Throttle Mechanism and single speed operation. A motor controller with multiple output voltage levels and Click Throttle Mechanism is presented in this paper which provides variable speed operation, better power utilization and is highly economical. Proposed modified KY converter utilizes the turns ratio of an On-Line Tap Changer (OLTC) to generate multiple output voltages for variable speed commutation. This possess a stable continuous conduction mode throughout its operation and reduced switching transients when compared to the existing topologies. Mutually independent control variables namely turns ratio and duty ratio, are used here for voltage conversion, which facilitates the flexible transition between multiple output voltage levels. A 15?W prototype of the proposed modified inductor coupled KY converter is realized using Arduino Uno Board.     

望远镜壳体注射模设计简

以滑块中加脱螺纹模具机构设计的方法，利用模具中的行程开关，解决了模具的脱模具问题，使模具生产的塑件符合塑件设计的质量要求，从而证明滑块中加脱螺纹模具机构设计的方法是正确的。     

Reduction of Vibration in Concentrated Winding Permanent Magnet Synchronous Motor by Means of Skew Effects of Rotor

Global warming and the problem of successfully incorporating environmental safeguards are promoting the need for a more power‐efficient motor. Therefore, as a driving source, permanent magnet synchronous motors (PMSMs) with concentrated winding are widely used in a variety of fields. However, a PMSM with a concentrated winding generates more vibration than one with a distributed winding because of the radial electromagnetic force. This paper describes the effect of a new skewed rotor on the characteristics of a concentrated winding PMSM. We investigated this effect by three‐dimensional finite element method (3D FEM) analysis and measurement. We also demonstrate that the proposed rotor is effective in reducing the radial electromagnetic force without decreasing motor efficiency. © 2014 Wiley Periodicals, Inc. Electr Eng Jpn, 187(2): 33–43, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22400