提高感应电能传输效率的研究

非接触式感应电能传输系统（ICPT）是一种新型的电能传输技术,通过感应电磁耦合向负载提供电能。ICPT的关键部件是松耦合变压器（也叫可分离变压器）它的耦合系数较低,制约着传输效率。本文对非接触感应电能传输系统进行了系统的介绍,并且分析了磁芯材料、工作频率、气隙大小等关键参数对传输效率的影响,着重讨论了可分离变压器的初次级绕组的补偿问题,并且给出了补偿电路的设计方案。     

松耦合感应电能传输效率分析

首先给出了非接触式松耦合感应电能传输的基本原理 ,电路结构采用半桥串联谐振电路,并用电容串联补偿,通过系统数学建模,把电路分为串联谐振变换器和整流电路两个部分,然后详细讨论了影响系统电能传输效率的关键因素.基于以上的分析讨论后,最后给出此类松耦合感应电能传输系统设计方法.     

LCL谐振型感应电能传输系统特性

相对于传统的电感电容(LC)谐振型感应电能传输系统,串并联(LCL)谐振型感应电能传输系统有更大的功率传输能力,但其特性更为复杂。针对LCL型感应电能传输系统的高阶非线性和复杂的频率特性,利用系统的互感耦合模型,对系统的谐振参数匹配方法、变负载情况下系统的频率特性以及功率传输特性进行了分析研究,给出了系统原边谐振参数、传输功率和效率的计算方法,最后通过仿真验证了理论分析的正确性。     

松耦合反激LED电源的分析与设计

在利用松耦合变压器进行电能传输的系统中,系统的工作频率和器件选取跟系统电能传输的大小有紧密联系.本文对松耦合变压器在反激电源中的应用做了分析,并对松耦合变压器的原边和副边的电压和电流波形进行了时域分析.确定了副边导通和关断的时刻,对系统的可行性有了直观的判断,为器件的选取提供了依据.     

基于SS补偿的非接触能量传输系统的特性分析

文中针对非接触能量传输系统,对其松耦合变压器的原副边线圈进行串联补偿(SS补偿)。在该种补偿状态下进一步分析了非接触能量传输系统副边输出电流与原边输入电流、输出电压与输入电压、输出功率与输入电压之间的关系。通过仿真,验证了上述分析的正确性。     

高速旋转部件非接触感应电能传输装置设计

为满足航空发动机转子动态参数非接触光电数据采集系统的供电需求,设计了一种适合高速旋转部件应用的非接触感应电能传输装置。简要陈述非接触感应电能传输技术的基本原理,充分考量高速旋转应用场合及光电数据传输电路的特点,提出采用螺旋线PCB板加柔性软磁片作为松耦合变压器的解决方案,给出具体的原副边电路及补偿参数设计方法,经实验验证该方案实现了7 V/3 A的稳定输出。     

感应耦合式无接触电能传输系统设计

感应耦合式无接触电能传输模式是一种极具潜在发展前景的电能供给方式。文章介绍了其系统构成和工作原理,建立了其核心器件——无接触变压器的数学模型。在此基础上,对次级补偿、变压器设计、反馈与控制方法进行了深入研究,提出了新的设计方案。然后运用所建立的模型,对系统进行仿真分析和验证。最后通过实际的电源设计,验证了以上分析。     

频率跟踪式谐振耦合电能无线传输系统研究

谐振耦合电能无线传输实际应用的瓶颈是谐振频率的失谐。本文基于谐振耦合电能无线传输机理和模型,分析了发射线圈与接收线圈的固有谐振频率变化对无线传输效率的影响和失谐机理,发现发射线圈电感变化是影响电能无线传输效率的主要因素之一,由此提出了发射功率源工作频率同步跟踪发射电路固有谐振频率的频率跟踪控制方法,从而保证了谐振耦合电能无线传输的谐振输电方式,避免了谐振频率的失谐,大幅度地提高了输电效率。文中制作了一个谐振频率为1MHZ的无线电能传输系统原理样机,验证了该方法的有效性。     

磁耦合谐振式无线电能传输系统建模与分析

磁耦合谐振式无线电能传输技术具有传输距离中等、传输效率高、能穿过非磁导性障碍物传输电能等优点,使其有望取代电池为物联网中的传感器节点无线供电。本文通过研究磁耦合谐振式无线电能传输机理,构建了传输系统的集总参数电路模型,对各模型参数进行了理论计算,并根据模型对不同传输距离下系统的传输效率与负载功率进行了分析,得出了不同耦合状态下系统获得最大负载功率的条件。     

基于谐振耦合原理无线电能传输装置系统的研究

无线电能传输技术是一种新型的电能传输技术,它可以克服有限电能传输方式的诸多弊端。本文分析并设计了一种基于近距离无线电能传输原理的传输系统,阐述了磁耦合谐振式无线传输系统工作原理,叙述了对系统的发射模块、接收模块的设计,分析计算线圈的电感量及传输效率及系统各部分参数对传输效率、功率的影响。     

Asynchronous transfer mode or synchronous transfer mode or both

Some of the problem areas attendant upon the asynchronous transfer mode (ATM) concept are addressed. Concern is chiefly with the use of small, fixed-length packets and the issue of congestion control. It is argued that broadband ISDN services should not be tied down to ATM as presently standardized, because ATM has several problems when embedded in a wide area network with diverse services     

Noninteractive oblivious transfer

Two new approaches to implement oblivious transfer and 1-2 oblivious transfer without interaction, based on the well-known Diffie-Hellman public-key distribution algorithm are proposed.<>     

GPS time transfer

The authors describe the use of GPS (Global Positioning System) for time coordination. When GPS first became available, it provided a quantum leap in time coordination with little or no effort on the part of the user. However, workers realized that with more sophisticated analysis techniques even greater accuracy could be wrung from GPS. The authors describe the level of time coordination these more sophisticated techniques have affected. The principles of GPS time transfer are described with emphasis on the so-called common view method. The sources of error during GPS time transfer are discussed and the various possibilities of reducing them are investigated. Some possibilities for overcoming SA (selective availability of GPS) are also discussed. GPS is additionally shown to be an outstanding tool for the dissemination of Coordinated Universal Time (UTC)     

Flux transfer devices

Flux transfer device theory is reviewed. In such devices, generalized magnetic flux, defined as the time integral of voltage, is used to describe the device characteristics. The Josephson junction and inductor are the main circuit elements in flux transfer devices, because they maintain a constant value for the time integral of voltage. Flux transfer devices are based on either an RF SQUID (superconducting quantum interference device) or a fluxon device. Four devices, including the parametric quantron and the quantum flux parametron, are reviewed as applications of the RF SQUID. The fluxon feedback oscillator and a soliton device are also reviewed as applications of fluxon devices. The quantum flux parametron is then described. The parametron principle and the fundamental properties of the quantum flux parametron such as gain, switching speed, and power dissipation are discussed. Logic circuits and a memory cell are also reviewed. A novel analog-to-digital converter is proposed as an application of the quantum flux parametron     

Design of auto-tuning capacitive power transfer system for wireless power transfer

This paper presents the design of capacitive wireless power transfer systems based on a Class-E inverter approach. The main reason for adopting the Class-E inverter approach is because of its high efficiency, theoretically 100%. However, the operation of a Class-E inverter is highly sensitive to its circuit’s parameters. In a typical capacitive wireless power transfer application, the capacitive coupling distance between plates is subject to changes, and hence its power transfer efficiency is greatly affected if the Class-E inverter is properly tuned. This drawback motivates us to develop an auto frequency tuning algorithm for a Class-E inverter which maintains its power transfer efficiency in spite of the variations of capacitive coupling distances between plates and circuit’s parameters. Finally, simulation and experiment are carried out to verify the effectiveness of the auto frequency tuning algorithm.     

屏蔽电缆转移阻抗和转移导纳的宽频测量

转移阻抗和转移导纳是表征外界电磁场对屏蔽电缆耦合机理的两个重要参量.基于传输线理论,提出了一种新的测量屏蔽电缆转移阻抗和转移导纳的简便方法.该方法既可以得到转移阻抗和转移导纳的幅频特性,又可以得到其相频特性,且测试系统比较简单.测试频率范围满足电力系统电磁兼容所关心的频段(0.1MHz～10MHz),对于更高频率屏蔽电缆转移阻抗和转移导纳的测量,可以通过选择更短的电缆样品来实现.为了验证测量方法的正确性,与现有方法的测量结果进行了对比.该测量方法可推广用于多芯屏蔽电缆的转移阻抗和转移导纳测量.     

Charge transfer and blooming suppression of charge transfer photodiode area array

A charge-transfer photodiode array combines the advantages of diffused diodes for broad and smooth spectral response and analog registers for low-noise readout. The device structure described is that of a high-speed low-blooming 100-by-100 diode array using bucket-brigade readout registers. Two of the mechanisms which are essential to successful operation of this combination structure are studied. These mechanisms are the charge transfer from sensing diode to the analog register and blooming suppression. It is found that the charge-transfer speed degrades sharply with reducing light level due to subthreshold leakage behavior of the MOS transfer gate. This degradation is eliminated by using a background charge supplied from the analog register. Experimental data confirms the validity of the concept.     

格基不经意传输协议

利用一个基于错误学习问题的陷门单向函数,在格上设计了一个3轮不经意传输协议。假设错误学习问题是困难的,证明协议实现了对接收者和发送者隐私性的保护。分析表明,协议中只使用小整数的模乘和模加运算,具有很高的计算效率;协议使用限制明密文扩展技术有效缩短了传输消息的长度,提高了协议的通信效率。     

Asynchronous transfer of video

Video transfers across IP and ATM networks have received much research attention during the last ten years. Various video services are expected in the future, enabled by the rapid development in video coding and broadband network technology. This article gives an introduction to the issues involved in asynchronous video transfers. Brief overviews of video coding, rate control, and multiplexing, as well as delay, error, and loss control are also given