基于空心螺线管互感耦合的能量传输效率研究

依据无线能量传输技术原理,研制了一套能量耦合传输系统,该系统采用空心螺线管组合作为能量耦合传输系统的核心部件(互感耦合器)。通过对36个自制互感耦合器的能量传输效率的实验测量,研究了不同规格与结构的空心螺线管组成的互感耦合器,在不同气隙下的能量传输效率的变化规律,以及互感耦合器原、副边采用电容补偿对能量传输效率的影响。这项研究是为了减小能量耦合传输系统的体积和重量、增强能量耦合传输系统的实用性所做的工作。本文对测量数据进行分析后,找到了一对能量传输效率较高的空心螺线管组合。由该空心螺线管组合构成的互感耦合器,通过对其原、副边进行电容补偿后,其能量传输效率在10mm气隙处达到了33.74%,在20mm气隙处达到了17.37%。使用其制作的能量传输系统,在外加+15V直流电压时,在20mm气隙处进行实测:系统输入功率约16.34W,输出功率约达到2.84W。实际输出功率已经能够满足小功率用电设备需求。     

Mutual inductance coefficient of air-core transformers

Contents The mutual inductance coefficient is determined in the case of regular and irregular winding of air-core transformers. The influence of the position of a straight, infinite conductor with current upon the value of the mutual inductance coefficient is analysed in the case when the conductor with current is situated inside the air-core transformer, perpendicular to its plane.

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Gegeninduktivitätskoeffizient eines Luftspaltstromwandlers

Übersicht In diesem Beitrag wird der Gegeninduktivitätskoeffizient eines Luftspaltstromwandlers für den Fall einer gleichmäßigen und ungleichmäßigen Wandlerwicklung ermittelt. Dabei wird der Einfluß der Lage eines geraden, unendlich langen stromdurchflossenen Leiters auf den Wert des Gegeninduktivitätskoeffizienten für den Fall, wo der Leiter im Inneren des Wandlers senkrecht zu seiner Ebene verläuft, analysiert.

     

干式空心电抗器设计软件开发与应用

基于等电阻电压的设计方法，开发了干式空心电抗器设计软件，提供解析法和有限无法两种计算方法，通过优化设计得到空心电抗器的结构参数，并给出电抗器的磁场和温度场分布，对不同安装方式和不同订货参数的空心电抗器都可以进行设计。以一种型号的空心电抗器为例，分别给出了三相平放和三相叠放时电抗器的参数。     

Fabrication and fundamental characteristics of a superconducting air-core autotransformer

With the recent advent of high-performance ac superconductors with very small ac loss and large current-carrying capacity, the possibility of an air-core superconducting transformer is being studied. Although the exciting current is very large, the air-core transformer has the following merits: (1) no iron loss; (2) no insulation care of the core; (3) no harmonics, and no in rush current induced by iron saturation, etc. Thus, the authors fabricated and tested a small experimental transformer (2.5 kVA, 330/150 V). As easily predicted, the exciting current becomes very large. It occupies about 45 percent of the rated current. Meanwhile, the leakage reactance increase considerably. The %IX becomes about 28 percent. These experimental results show good agreement with the theoretical analysis based on an equivalent circuit.     

非均匀空心线圈偏心误差建模研究

空心线圈的偏心误差关乎智能变电站的安全稳定运行以及电能的可靠计量。以往研究多集中于均匀空心线圈的偏心误差,对非均匀空心线圈的偏心误差研究不够深入。文中建立均匀和非均匀空心线圈的偏心误差模型,分析了互感系数和偏心距离、不均匀度、相对位置以及线圈结构等影响因素的关系,仿真结果表明了当载流体不偏心时,不均匀度不会影响偏心误差;当载流体偏心达到线圈内径的1/4时,不均匀度仅有0. 5°时便足以造成10%的互感系数误差。对3个不同参数的空心线圈进行了准确度试验,试验结果表明当偏心距离小于4 mm,空心线圈比差不超过0. 2%。偏心距离变化至16 mm,空心线圈比差的将超过了1%。空心线圈的角差不受偏心距离的影响。     

阀用螺管式电磁铁的双线圈优化设计

螺管式电磁铁是电磁铁中应用最广、产量最大的一种。由于电磁系统磁场与温度场分布不均匀以及磁性材料性能的非线性等原因,造成吸力计算及温升控制较为复杂。电磁阀设计主要解决的是密封和温升问题,必须对电磁阀、弹簧力和气体压力进行准确计算确保气路的通断,并且保证正常工作情况下的温升。因而电磁铁的电磁力与密封和温升息息相关。采用双线圈,选择合适的软磁材料、电磁铁结构和漆包线设计电磁铁,在通电1h内保证磁力的同时温升不超过100℃。ANSOFT软件仿真及实验证明了优化设计的可行性和有效性。     

On the derivation of current-mode floating inductors

It is shown that current-mode floating inductors can be derived from two basic circuit topologies based on operational transconductance amplifiers. Most of the well-known active inductors can be derived by replacing the transconductance amplifiers in the basic topologies by equivalent circuits incorporating current conveyors. By this consideration the relationship between apparently unrelated circuits is shown and new circuits are derived in a systematic way. © 1997 by John Wiley & Sons, Ltd.     

Simplified modelling of an air-core reactor for lightning impulse transient studies

This paper presents a methodology that can be used to model the electromagnetic behaviour of large disk type air-core reactors when excited by fast transient voltages having a frequency content ranging from 10 kHz to 500 kHz. The subject of transient voltages in complex winding structures has been extensively studied for more than a century resulting in increasingly complex model synthesis and parameter acquisition methods to increase accuracy. The novelty in this work however, lies in the study of a particular composition of simple well-known methodologies and an analysis of its suitability this context. A lumped parameter white-box model is generated using the design details of the reactor. The model parameters are calculated analytically and frequency dependency is mostly omitted for the sake of simplification in the methodology. The parameters are verified by measurements and finite element method simulations. The modelling methodology is applied to an actual case study and the simulation results are compared to the measured results. The model response varies in its performance. The results are good when evaluating the voltages to ground in the frequency domain. However with evaluation in the time domain it becomes clear than the methodology still needs improvement. Restrictions and limitations of the simplified model are discussed.     

遗传算法在空心电抗器优化设计中的应用研究

在干式空心电抗器设计中以等电阻电压法作为计算方法,采用遗传算法进行优化。给出了设计变量的编码方式,离散变量不需要重新规划。对遗传算法的适应度线性尺度变换和最优保存策略作了改进,在遗传操作过程中离散变量和连续变量采用不同的交叉和变异方式。以一种空心电抗器为例,优化后电抗器的外径、高度、重量和损耗分别减小了9%,41%,41%,15%,表明在空心电抗器优化设计中采用改进的遗传算法取得了良好效果。     

Accurate evaluation of the magnetic field strength of largesubstation air-core reactor coils

A circular cylindrical conductor segment is a basic modeling element of substation air-core reactor coils. The analytical expressions for evaluating the stationary and quasi-stationary magnetic field strength of a segment are derived. In the derivation, a surface source model is developed to substitute the given volume current distribution by equivalent surface sources. The magnetic flux density of sample coils is calculated by using the derived equations. The results are compared with those obtained by the finite element method. Good agreement is observed. The derived equations are very useful for solving problems that involve the accurate calculation of the magnetic field distribution around a coil, the magnitude of forces on a coil, the current distribution in the conductors of a coil and the inductive properties of a coil     

柔性螺旋电感的射频特性分析及建模表征

介绍了基于低成本塑料基体的柔性螺旋电感的制造工艺、射频特性分析及建模表征。柔性电感与传统的硅基体的螺旋电感性能相比性能更具有优势,电感值为6．2nH的柔性电感的 Q值最大值为14．2,自振频率达到了9．2 G Hz。并提出了表征柔性平面螺旋电感的等效电路模型,模型仿真数据与实验数据取得了一致性。最后通过模型参数的仿真分析提出了优化柔性电感性能的方案。该研究为柔性电感的设计与应用提供了指导依据。     

大型三相空心电力电抗器相间电磁力计算

从电磁场的基本原理出发，求得了计算非同轴安装情况下大型空心电力电抗器相间电磁力的解析计算公式，使得三相电抗器之间的电磁力可以通过简单的数值积分计算办法而求得，为三相空心电力电抗器的动稳定校核和故障情况下相间电磁力的计算提供了理论计算公式和便利。     

大功率工业磁芯电感测量方法探讨

关于电感量的测量,大家认为用电感表测量一下就行了。但是实际情况是：大功率工业用磁芯电感在实际工作条件下的电感量工和电感测量仪表测量条件下所测的电感量相差很大。本文揭示了造成这种误差的原因,并提出了测量方法。     

小型带不可控整流负载异步发电机自激电容确定

针对异步发电机带整流系统稳态运行后其电路为多回路、变拓扑结构,直接采用电流回路法分析极为困难复杂的特点,根据异步发电机定、转子边的电势平衡关系列写电压方程式,然后把方程式折算到基值频率,得到能够进行稳态分析的电机一相等值电路。在忽略整流桥有功损耗的前提下,引进功率平衡法将直流侧、交流侧联系起来,结合电机的等值电路,建立了异步发电机带整流负载系统的完整数学模型,该模型不仅分析过程简便,而且具有较高的分析精度。     

Design and analysis of thick-film integrated inductors for powerconverters

This paper describes the design procedures followed to obtain a thick-film inductor for its application in DC/DC power microconverters. The main characteristics of the new technology used are commented upon and design equations are given. Results are compared to those obtained by means of finite-element analysis tools. Details of some thick-film inductors developed with this technique (within the framework of the IMPASS Esprit Project (number 23910), financed by the European Community) are also given. The inclusion of one of these inductors in a 5-to-3.3-V DC/DC converter contributes to obtaining a very high power density: 6.25 W/cm³     

叠装式干式空心电抗器温度场仿真与实验分析

电抗器的热稳定校核是生产设计中的重要指标,温度监测是检修维护的重要环节。电抗器温升过高造成包封绝缘损坏,严重时引发烧毁事件。文中基于有限元的方法,运用电磁场-流场-温度场理论对三相叠装式干式空心电抗器进行了温度场的仿真计算,提出了电抗器包封温度在轴向上和径向上的分布规律。研制基于物联网模式的干式空心电抗器温度在线监测系统,对某变电站内电抗器进行了多点温升测试。通过对比分析,仿真值与测量值吻合良好。研究成果能够为干式空心电抗器的温度在线监测与故障诊断提供理论基础和参考依据。