任意排列三相绕组参数的计算

对任意排列三相绕组的谐波进行分析,推导了任意排列三相绕组的谐波单位漏磁导,得出任意排列三相绕组槽口及槽底节距漏抗系数的计算公式。     

单相异步电动机定子谐波漏抗的理论分析

阐明计算单相异步电动机定子谐波漏抗时,不能采用三相电机的有关公式、图表,文中按照气隙磁场特点分析推导出同心式、正弦及叠绕组的∑S值。     

三绕组单相感应电动机的性能分析与实验研究

针对三相感应电动机可以替代单相电动机接于单相电网运行,提出将三相感应电动机的一相绕组与电容器串联后再与另外一相绕组并联,然后与第三相绕组串联,构成Y接法三绕组单相感应电动机。基于等效电流法,对三绕组单相感应电动机的运行性能进行研究,建立三绕组对称运行的条件,分析匹配电容对电机性能的影响。结果表明由于电容器的影响,无法实现严格对称运行,提出依据额定负载下电磁转矩最大为目标函数的电容器优化方法。采用该联结方式在一台2.2 kW电机上进行了实验,结果表明选择适当的电容将提高电机的效率,与三相对称电机在三相对称电源上的运行相比较,该接法的电机具有较高的功率因数,且效率接近三相对称运行时的效率。     

三相正弦绕组槽漏抗的计算

1．引言三相正弦绕组（又称低谐波绕组）是通过绕组线圈的不等匝设计，使电机气隙内的磁势呈正弦分布，以达到完全消除或消弱除齿谐波外的高次谐波磁势。从而改善电机性能，使温升降低，振动和噪声减小，效率提高，并减少原材料。由于三相正弦绕组的显著优点，已被许多厂家所认识和采用，三相正弦绕组一般为双层同心绕组，另外还有一种△－Y混合联接的绕组，本文仅推导双层同心绕组的槽漏抗计算公式。双层同心绕组因其上下层匝数不等且绕组型式也与文献1中有所不同，所以槽漏抗的计算与传统等匝线圈槽漏抗的计算有很大区别。2，三相正弦同…     

关于不等相带、不同匝数的不对称三相绕组电机的漏抗

本文指出,应用于对称三相电路的对称分量法不能简单地移用到不对称三相绕组电机的电路,并对不等相带、不同匝数的不对称三相绕组电机的漏抗进行分析,得出了相应的计算公式     

通用谐波漏磁计算法

本文从气隙能量法中推导出一个通用的数值计算方法,能一次性的精确计算交流电机中谐波漏磁,并且容易在计算机上实现,计算时间也省。 本方法具有广泛适用性,能决定所有单相或多相绕组,规则或不规则绕组的谐波漏磁。文中例举了一些计算结果,与传统计算方法所得结果作比较后证明本方法的有效性和实用性。 本文方法尚适用于精确计算各种周期性波形的畸变率。     

三绕组新型接法单相电动机的研究

普通单相感应电动机在单相供电系统中,当电动机额定功率比较大时是不经济的。该文提出了一种新型连接方式的三绕组单相感应电动机,对感应电动机的三相绕组进行了改接,并与电容器相连,改变了绕组中电流的相位,使三相电机在单相供电系统中实现接近对称运行。采用合成电流法研究了该连接方式下电机对称运行应满足的条件,讨论了对称运行条件下电容的选择及其对电机性能的影响。对该连接方式进行了试验研究,并与三相对称运行进行了比较,证明了新型接法三绕组电机的效率接近在三相电源上对称运行的效率,并且具有更高的功率因数。     

新型接法的三绕组单相电动机

在单相供电系统中,当电动机额定功率大于0.5 kW时,采用普通单相感应电动机是不经济的,为此提出一种新型连接方式的三绕组单相感应电动机,该接法对Y接法三相感应电动机的6个出线头进行改接,并与2个电容器相连接,改变了绕组中电流的相位,使三相电机在单相供电系统中实现接近对称运行。采用对称分量法研究该连接方式下电机对称运行需要满足的条件,讨论对称运行条件下电容的选择及其对电机性能的影响,推导了该电机性能计算的具体方法。针对该连接方式进行试验研究,并与三相对称运行进行比较。样机试验证明,新型接法三绕组电机的效率接近三相电动机在三相电源上对称运行的效率,且具有更高的功率因数,可替代普通单相感应电动机。     

单相电机槽满率的机辅计算程序

单相电机槽满率的机辅计算程序汪建华单相交流电机为了削弱或消除高次谐波，改善电机性能，电机的绕组一般采用正弦分布绕组。正弦分布绕组即电机每极下各槽导线数按正弦规律分布，其特点是各槽导线数不相等。因此在计算单相电机槽满率时，由于单相电机绕组系数的多样性，...     

任意排列三相绕组参数的计算

介绍并推导了非正规排列绕组三相异步电动机谐波分析、谐波单位漏磁导及节距漏抗系数用于工程设计的计算方法。     

Watermarking on CNN‐UM for image and video authentication

In this paper a new approach to fragile watermarking technique is introduced. This problem is particularly interesting in the field of modern multimedia applications, when image and video authentication are required. The approach exploits the cellular automata suitability to work as pseudorandom pattern generators and extends the related algorithms under the framework of the cellular non‐linear networks (CNNs). The result is a novel way to perform watermarking generation in real time, using the presently available CNN‐universal chip prototypes. In this paper, both the CNN algorithms for fragile watermarking as well as on‐chip experimental results are reported, confirming the suitability of CNNs to successfully act as real‐time watermarking generators. The availability of CNN‐based visual microprocessors allows to have powerful algorithms to watermark in real time images or videos for efficient smart camera applications. Copyright © 2004 John Wiley & Sons, Ltd.     

水库防洪优化调度自适应拟态物理学算法

拟态物理学算法(APO)是近年来一种新颖的基于物理定律启发的智能算法,本文提出了利用智能算法求解水库防洪优化调度模型的通用启发式策略,阐述了拟态物理学算法的基本原理,尝试通过自适应方式合理设置算法的引力参数,同时改善标准算法的寻优进程,提出了自适应拟态物理学算法(AAPO)。将其应用于鲇鱼山水库实时防洪优化调度模型求解,采用最优值的均值和方差衡量算法的精度和稳定性,并对水库最优出流方案分段采用波动率衡量算法应用可操作性,同时统计计算机耗时,结果表明:自适应拟态物理学算法较标准算法搜索精度更高,寻优结果更稳定;且拟态物理学算法较其他算法计算的水库泄流方案的过程线波动变化更小,实时防洪调度应用可操作性较高。     

多相并联磁集成电压调整模块的电路建模研究

针对磁集成磁路耦合和建模分析的难点,提出了一种基于回转器-电容模型的磁集成建模方法。在该模型中,磁性参数中的磁导类比于电路中的电容,绕组励磁类比于电流控制电压源型回转器。文章首先利用回转器-电容模型对两相电压调整模块进行建模研究,并推导出具体的磁集成自感和互感表达式;然后根据该建模方法推导出多相并联磁集成的电路模型,并利用相似矩阵对角化原理求解得到通用模型表达式;文章最后比较了利用回转器-电容模型的磁集成电压调整模块的仿真与实验结果。研究表明,该模型与实际应用相吻合,能仿真磁集成电路的稳态和动态特性,为磁集成建模提供了一个新的研究思路。     

Boost功率因数校正变换器单周期控制适用性的理论分析和实验验证

当输入或者负载跳变时,单周期控制是功率变换器中一种新型的非线性控制策略,单周期就可实现控制目标.然而,单周期控制在功率变换器中的普适性并没有相关研究,限制了它的进一步发展和应用.该文以Boost变换器作为研究对象,引入切换线性系统的概念和理论,基于Boost变换器切换线性系统模型严格证明单周期控制在Boost变换器中的适用性,由此提供一种单周期控制在一般功率变换器中适用性分析方法.在理论研究的基础上,给出了单周期控制Boost变换器实现功率因数校正的一个实际范例.     

A novel QCA implementation of MUX-based universal shift register

QCA (Quantum-dot Cellular Automata) is an alternative technology for CMOS that has a low power consumption and high density. QCA extensively supports the new plans in the field of nanotechnology. Applications of QCA technology as an alternative method for CMOS technology in nano-scale have a hopeful future. This paper presents the successful design, implementation and simulation of 2 to 1, 4 to 1 and 8 to 1 multiplexer with the minimum area as compared to the previous models in QCA technology. In this paper, by means of 4 to 1 multiplexers including D-Flip Flop (D-FF) structure in QCA, we present an 8-bit universal shift register. The structure of the 8-bit universal register is extendable to 16-bit, 32-bit and etc. In this paper, the successful simulation of 2 to 1, 4 to 1 and 8 to 1 multiplexers, including D-FF and finally 8-bit universal register structure in QCADesigner is provided. The multiplexers and D-FF presented in this paper have the minimum complexity, area and delay compared to the previous models. In this paper, the implementation of 8-bit universal shift register, by means of 4 to 1 multiplexers and D-FF are presented in QCA technique which have the minimum complexity and delay. In the proposed design of the 8-bit universal shift register, the faults are likely to occur at 2 to 1 multiplexers and D-FF. In this article, 2 to 1 multiplexers and D-FF are investigated from the cell missing and possible defects. Considering the pipeline being the virtue of QCA, the 8-bit universal shift register has a high speed function. This 8-bit universal shift register may be used in the high speed processors as well as cryptography circuits.     

PCI通用板卡结构

介绍一种基于PCI总线的板卡结构，对可编程逻辑器件和专用接口芯片两种实现方案进行讨论。     

The `universal' dielectric response. I

A novel approach to the interpretation of the dielectric response of solids, in terms of the concept of the universal dielectric law of relaxation, is presented. The universal approach moves away from the earlier interpretations that relied heavily on the concept of distributions of relaxation times (DRTs) of Debye-like processes that are supposed to coexist in a given material and constitute a superficially plausible model. It is argued that the DRT explanations do not stand up to critical examination. The new interpretation is based on the unique property of the empirically determined fractional power laws in frequency that the ratio of the imaginary to the real parts of the complex dielectric susceptibility is independent of frequency, in sharp contrast to the Debye law, where the ratio is proportional to frequency. The significance of the approach is illustrated by showing, in connection with the interpretation of low-frequency dispersion, that it impinges on many phenomena in physical chemistry and electrochemistry. It can also be used to advantage to study the delayed transitions of localized electrons in semiconductors and similar materials     

A Universal Fault Location Technique for N-Terminal $({N}geqq 3)$ Transmission Lines

This paper presents a universal fault location technique for N-terminal transmission lines based on synchronized phasor measurement units. The development of the technique is based on two-terminal fault location technique. The proposed algorithm is different from traditional multiterminal fault location techniques. We apply two-terminal fault location technique to N-terminal transmission lines and propose a novel fault section selector/fault locator. The proposed method has a very good tolerance. The proposed approach provides an analytical solution and its computational burden is very low since it does not require iterative operations. An extensive series of simulations were conducted to verify the accuracy of the proposed algorithm. The average fault location error under various fault conditions is well below 1%.     

Testing and development of alternative flexible-bus geometries for interconnected substation equipment subjected to earthquakes

This paper presents the results of a study aimed at developing alternative flexible-bus geometries in an aim to minimize earthquake effects on interconnected substation equipment. The approach chosen was to develop universal configurations that could be applied between any given pairs of components for a given voltage level and specific ground acceleration. Both dynamic testing and the nonlinear finite-element method were used to achieve this goal. The main product of this study takes the form of tables for each voltage level considered recommending one or more configurations according to the span.     

Design of efficient fir digital differentiators of second and higher degrees by using universal weights

We propose in this paper an efficient design of FIR digital differentiators of degree k, k= 1, 2, 3,…, and their implementation in a novel structure which allows the order to be varied without having to alter the weights used in it. More precisely, we show that by using these ‘universal weights’ in a structure of order N_max, the order can be varied from N= 3 to N_max while keeping the weights fixed and retaining the optimality of performance. Mathematical formulae have been derived for these ‘universal weights’ for differentiators performing in the low- or midband-frequency ranges.