试论特高压共走廊输电线路电磁耦合分析及改善措施

在雷电天气中,雷击现象会引发特高压共走廊输电线路的电磁耦合,进而影响电力设备的正常使用.本文从电磁耦合的概念入手,对特高压共走廊输电线路的电磁耦合及改善措施进行分析和研究.     

特高压输电系统过电压限制分析

本文介绍了特高压输电系统过电压问题,并从特高压输电系统过电压以及工频过电压两个问题出发,给出了具体的过电压限制策略.     

Through-silicon-chip transmission lines

Through-chip transmission lines connecting the frontside and backside of high-resistivity wafers are fabricated using bulk-micromachining and backside metal patterning. Experimental results illustrate the feasibility of low-loss through-chip microstrips and coplanar waveguides for innovative integration concepts of radio-frequency and microwave systems in silicon technology     

Metal-insulator-semiconductor transmission lines

This paper investigates the one-dimensional metal-insulator-semiconductor transmission line. It develops closed-form expressions for equivalent-circuit parameters, compares them to exact calculations, and explores their limitations. It also investigates the usual assumption of single-mode propagation and shows that, in certain fairly common circumstances, the fundamental mode of propagation becomes so lossy that it can no longer be considered to be the dominant propagating mode     

浅谈特高压输电工程关键技术

文章通过对特高压的发展历程、国内外特高压关键技术及已投运的特高压的运行管理情况的介绍,进一步明确了未来特高压的发展方向,为洲际能源互联,全球能源互联网的实现奠定基础。     

特高压交流电力线路仿真模型的创建

特高压电力线路运行特性不同于一般高压电力线路,进行特高压交流电力线路特性研究需要创建电力线路仿真模型。文章以均匀传输线理论为基础,对特高压电力线路4个参数进行分析,得出特高压交流电力线路单位长度电导G0表达式,推导得出特高压交流电力线路考虑分布参数特性的数学模型,并在Matlab仿真软件平台创建仿真模型,为特高压长距离电力线路运行特性研究奠定基础。     

The method of lines applied to planar transmission lines incircular and elliptical waveguides

The method of lines (MOL) is utilized to analyze a class of planar transmission lines with circular or semicircular/elliptical metallic shielding. The authors show how the general MOL principles can be modified so that curved boundary structures can be included. Dispersion diagrams are presented for microstrip and slotline structures with curved metallic shielding as well as for their suspended counterparts in circular and elliptical waveguides. Results show that some of the structures have potential applications at millimeter-wave frequencies because losses in circular waveguide enclosures are generally lower than those in rectangular waveguides     

特高压直流输电线路保护新原理研究

本文重点研究特高压直流输电线路保护的相关问题,先介绍了特高压直流输电系统建模仿真的基本思路,再对特高压直流输电线路暂态能量保护策略进行深入研究,希望能对相关人员工作有所帮助.     

3S技术在特高压输电线路工程中的应用研究

输电线路是整个电网建设的躯干,决定着电网运行的稳定和安全。因此,输电线路的勘测和设计在输电线路工程中扮演者重要的角色,也是电力系统运行的重要保障。随着电网系统的完善和特高压输电线路工程技术的发展,遥感技术、地理信息系统技术以及全球定位技术在工程中得到了广泛应用,为工程进行提供了数据收集、分析以及处理等支持,为设计人员和工程人员提供了参考依据。因此,3S技术的引入为输电线路的整体建设和运行的整体安全提供了保障,也进一步推动了电网建设输电线路工程的可持续发展。基于此,本文将在特高压输电线路建设现状及对3S技术需求分析的基础上,进行3S技术在特高压输电线路工程中的应用研究,希望能够为工程建设和电网完善提供一定的参考。     

Overview of quasi-planar transmission lines

A number of quasi-planar transmission lines are reviewed in terms of the general propagation characteristics including useful features, precautions in practice, and some design information. Transmission lines discussed here include coplanar waveguides, finlines, suspended stripline, and microslab waveguides. Attenuation characteristics of some of these lines are compared. The problem of discontinuity characterizations is discussed     

Simulink simulation of transmission lines

MATLAB can manipulate and invert large matrices and can be used in many numerical applications. MATLAB's capabilities can be extended with a recent addition called Simulink, a program which is normally used in the analysis and synthesis of modern control systems. Simulink, now incorporated into MATLAB, can also be used to analyze distributed transmission lines. Hence, it can be directly used in the analysis and design of microwave, electric power, and VLSI networks. In addition to demonstrating its wider applicability, we include several examples that are normally described in books or papers directed to the study of pulse propagation along transmission lines     

CHARACTERISTICS OF MICROSTRIP TRANSMISSION LINES

An efficient hybrid field solution to microstrip transmission lines is presented byusing SLE and SLM modes in spectral domain.It by-passes the lengthy process of formulatingthe determinant equation for the unknown propagation constant.Compared with spectral domainadmittance approach,this method is clear in both physical and mathematical senses and may beapplied to a variety of structures.     

特高压直流输电系统对电网谐波污染的仿真分析

本文首先介绍了特高压直流输电技术,并以具体案例为基础,对特高压直流输电系统对电网的谐波污染展开了仿真分析过程,最终对仿真结果进行了讨论.     

The importance of losses in the coupling of transmission lines

A simple model for weakly coupled lossy transmission lines of finite length has recently been proposed by Olsen (1984). He derived a simple formula for the coupling voltage on a load situated at one extremity of the undriven wire. The importance of the coupling due to losses on this voltage with respect to the coupling due to capacitance and inductance is investigated in this paper. It is found that only in a special case, called the resonance matching case, is the role of the losses dominant in the coupling process. This case is characterized by the condition that the characteristic impedance of the wires squared by equal to the product of two loads Z_LG and Z _0R situated at opposite ends of the driven and the undriven wire     

The K-pulse and response waveforms for nonuniform transmission lines

Application of the K-pulse concept to a class of distributed-parameter systems which can be modeled by finite lengths of nonuniform transmission lies is demonstrated. The K-pulse of such a system is the excitation (input) waveform of finite duration which yields response waveforms of Finite duration at all points of the system. Numerical techniques using a finite element method are developed to derive accurate approximation of the K-pulse and response waveforms for uniform and nonuniform transmission lines. Comparison is made with exact results to illustrate the accuracy and utility of the method.     

Surface losses in transmission lines

Two derivations of the loss parameter R, entirely from wave considerations in the presence of a metallic interface, are presented. R, which represents surface losses, occurs in transmission line equations for propagation of the voltage across the plates and of the current in the plates. Explanation of the surface losses involves some radiation of the interior fields into the metallic surfaces that absorb electromagnetic energy, and that ultimately convert it into ohmic losses (heat). Although the approach may restrict the derivation to a planar interface, i.e., to a parallel-plate transmission line, that restriction is not so essential that it cannot be softened     

Miniature superconductive coaxial transmission lines

This is a review paper concisely tracing the development of miniature superconductive coaxial transmission lines from the original invention as a vertical channel signal delay line for fractional nanosecond pulse oscillography to present-day work towards highly compact, broad-band, and low-loss telecommunication cables. The present state of development yields a 1.6-mm coaxial line operating at 4.2K and having Pb conductors, polyethylene dielectric, Z0= 50 ± 0.3 Ω and a 1-GHz attenuation of the order of 1 dB/km. The attenuation up to 1 GHz is mainly due to dielectric losses.     

Crosstalk between microstrip transmission lines

Methods for prediction of crosstalk between microstrip transmission lines are reviewed and simplified for the weak-coupling case. Classical coupled transmission line theory is used for uniform lines, and potential and induced EMF methods are used for crosstalk between nonuniform lines. It is shown that the potential method is equivalent to classical coupled transmission line theory for the case of uniform lines. An experiment was performed for uniform coupled microstrip lines for frequencies from 50 MHz to 5 GHz, and good agreement between theory and measurement was obtained for both near- and far-end crosstalk     

End-effects in quasi-TEM transmission lines

Magnetostatic analysis of a finite-length two-wire transmission line yields simple closed-form expressions for inductive end-fringing and interaction between ends. A further argument relates the results to capacitive end effects. Application to microstrip-like lines, twin-strip line and coplanar waveguide is outlined. It is demonstrated by explanation and comparison with the literature that these effects are the dominant discontinuity elements in short lengths of line, vias, resonators, bends, and other basic microwave configurations     

Transient analysis of lossless transmission lines

The method of characteristics provides a simple analytic solution for the transient analysis of a uniform, lossless transmission line. The interpretation of this solution in terms of equivalent network of the input and output behavior of the transmission line leads to an efficient algorithm which yields not only the input and output responses but also the incident and reflected waves. This method is superior in both speed and accuracy to the familiar method of integrating the differential equations that describe a lumped LC model of the line; but it is not applicable to lossy lines.