浅析高压输电线路的状态检修方法

高压输电线路主要的作用是输送和分配电能,变电站和各发电厂都是同步运行,所以高压输电线路是电力系统的重要组成部分,也是电力工业的主体。为了保证高压输电路的质量和进度,所以高压输电路施工是工作中的重点,高压输电路的状态施工面临着多样化的环境,要对具体问题具体分析,及时诊断缺陷和解决的方法。从工程实践中提出了相应的看法和对策。

高压输电线路的状态检修方法分析

高压输电线路的作用主要是输送和分配电能,变电站与各个发电厂是同步运行的,因此电力系统重要的组成部分就是高压输电线路,高压输电线路也在电力工业中处于主体地位。所以为保证高压输电路的进度和质量,在施工中要重点做好高压输电路建设。而在实际情况中,高压输电路施工也面临着多种多样的环境,要对具体问题进行具体的分析,及时的诊断出施工中存在的缺陷以及找出解决的方法,还要在工程实践中根据实际情况提出合理的策略。

浅谈高压输电线路运维管理工作难点及对策

在人类文明高速发展的今天,电力能源的需求不断扩大,是驱动我国特色社会主义现代化的大事项,电力行业逐步加大了对高压输电线路的建设,其稳定性直接影响了电力能源输出安全,运维管理工作的有效展开则是重要保障。在实际开展过程中其稳定性受多重因素影响,包括主观方面和客观方面,造成了一定的高压输电线路运维管理工作困难,相关方面的课题研究备受关注和热议。该文基于对高压输电线路运维管理工作难点的梳理分析,就其相应的优化对策展开了深入探究。

浅谈高压输电线路电气设计的问题及改进

架空线路与电缆线属于输电网中常见的高压输电电路,但采用何种方式要整体分析其优劣。架空线路施工难度很大,并且还有被雨雪袭击或是雷电击中的影响。反之,地下安装电缆有较大优势,不但可以节约施工空间,并且美观整洁,可是该种方式的缺点在于电缆线检修困难。因此,高压输电线路具体设计中需要全面考量多种影响因素,根据高压线路情况,选取规范的设计方案,并进一步改进与优化设计方案。

输电高压线路的检测与维护技术分析

输电高压线路作为电网的重要组成部分,担负着电网电能的传输重任,其健康状况对电网的安全稳定运行有着重要的影响。本文对输电高压线路检修与维护的内容和技术进行了探讨,以期为高压输电线路的检修与维护能够发挥积极的借鉴作用。

输电高压线路的检测与维护技术分析

当前随着我国的经济和科技全面发展,人们在日常生活中追求经济发展的同时,加强了对 电力资源的需求。在社会建设发展下,为了保证用电的稳定性,电力系统中输高压输电线路整体越来越 多。在这一发展状态和发展形势下,工作人员的工作任务在逐渐的增大。在输电高压线路应用的过程 中,可以更加有效的确保电网系统稳定运行。技术管理人员开展输电高压线路检修和维护管理工作,技 术人员提升输电线路维护和管理工作,这样可以有效的保障电力系统状态的稳定性。文章主要对输高压 输电线路运行形式进行分析,为输电线路更好的发展提供有效的参考。

NEW PRINCIPLE FOR DIRECTIONAL COMPARISON CARRIER PROTECTION OF EHV TRANSMISSION LINES

The increasing scale and complexity of power systems require high performance and high reliability of power system protection.Protective relaying based on directional comparison with power line carrier or microwave channels is the most suitable protection scheme for long distance EHV transmission lines and is widely used in power systems.The key element of such protection is a directional relay used to discriminate the fault direction.In order to overcome the disadvantages of conventional directional relays,the authors of this paper put forward the directional comparison carrier protection based on the artificial neural network(ANN).The protection is extensively tested using electromagnetic transient program (EMTP) under various electric power system operating and fault conditions.It is proved that the directional comparison carrier protection based on ANN,which can recognize various fault patterns of the protected transmission line(such as fault direction,fault phases etc.)correctly in any kind of operating and fault conditions and the whole process,is satisfactory for EHV transmission line protection.

Nonlinear dynamical response of high-voltage transmission lines based on cable dropping

In order to study the dynamic response of high-voltage transmission lines under mechanical failure, a finite element model of a domestic 500-kV high-voltage transmission line system is established. The initial equilibrium condition of the coupling system model is verified by nonlinear static analysis. The transient dynamic analysis method is proposed to analyze the variation law of dynamic response under cable or insulator rupture, and the dynamic response of structural elements next to the broken span is calculated. The results show that upper crossarm cable rupture has no effect on cable tension at adjacent suspension points, but it has a significant influence on tension in the insulator and the tower component of the upper crossarm next to the broken span. The peak tension in the conductor of the upper crossarm at the suspension point exceeds the design value under insulator rupture. Insulator rupture has no effect on the tower component of the upper crossarm, but it has a significant influence on insulator tension of the upper crossarm. Insulator rupture should be taken into account in the design of overhead transmission lines. The research results can provide a theoretical basis for the design of transmission lines.

Modeling of electrode system for three-phase electric arc furnace

To simulate the process of electrode operation, a dynamic model describing the electrode system of three-phase electric arc furnace was developed. This new model can be divided into three submodels in terms of the practical situation. They are the power supply system model the electric arc model and the hydraulic actuator system model. According to the basic circuit theory, the power supply system model where the high voltage transmission circuit and mutual inductances were considered, was set up. The electric arc model, which was novel for the electrode control, served as the electrical load and was connected to the power supply system model. The hydraulic actuator system model consists of the proportional valve part that is modeled to capture the dead-zone nonlinear characteristics and the hydraulic cylinder part where the impact of the load force is taken into account. By comparing simulation data and actual data, the results show that the electrode system model is proved to be accurate.

Geospatial Solutions in Practice for Smart Grids

Recently, smart grid solutions have started to extend the visibility of the electrical grid to the entire network; including high voltage transmission lines, medium voltage distribution networks, and the low voltage networks to households. The typical data monitored includes： voltage, current, phase, and power measurements, together with network events and alarms. This paper analyses the key challenges facing smart grid solutions in providing effective access to large volumes of sensory data that is distributed over a large geographic area. A case study is described that outlines how the use of geospatial technology together with Web 2.0 technologies may be applied to improve user access and control to this data. The results show that a geospatial solution provides an effective mechanism for visualizing telemetry data monitored within the smart grid.

Novel Algorithm for Estimating the Distance of Open-Conductor Faults in HV Transmission Lines

This paper presents an ANN （artificial neural networks）-based technique for improving the performance of distance relays against open-circuit faults in transmission networks. The technique utilizes the small capacitive current measured in the open-phase plus the currents in the two healthy phases in calculating the open-circuit fault distance. The results obtained show that a distance relay with the proposed scheme will not only be able to detect the open-conductor condition in HVTL （high voltage transmission line） but also to locate the place of this fault regardless the value of the pre-fault current loading. There is no need for especial communication schemes since the existing media could work properly for the needs of the proposed technique.

A Novel Technology for Generation of Electricity and Cold by Using Energy Potential of Transmission Line＇s High Pressure Gas

The main objective of this paper is to develop a novel technology for combined generation of electricity and cold by using energy potential of transmission line＇s high pressure gas. For this purpose, the reduction of high pressure of the gas in gas distribution station instead of useless expansion throttling process is suggested to realize by adiabatic expansion, which is executed in a gas expanding turbine. Herewith, the gas distribution station is turned into energy and cold generating plant. Simultaneous operation of energy and cold generating plant is described. A method and appropriate formulas for determination of design characteristics of considered plant are suggested. A new method for reveres order of calculation and design of the cold store based on the use of expanded cold gas as cooling agent is developed. Calculations and analysis prove high energy efficiency of suggested technology, the wide use of which will provide significant production of cheap electricity and cold and as well as reduction of fossil fuel consumption.

Modeling of an ionized electric field on the building near the UHVDC transmission line

In this paper,a 3D upstream finite element method is developed to analyze the ionized electric field around the UHVDC transmission lines including the building near it.The ionized electric field around the building is reduced due to the shielding effect of the building and the shielding distance is about three times its height.The ionized electric field including the human body model on the building and away from the building is also taken into account.The ionized electric field distortion ratio of the human body model is discussed in this paper.The distortion ratios for the positions on the building are less than those on the ground.

Fault component integrated impedance-based pilot protection scheme for EHV/UHV transmission line with thyristor controlled series capacitor(TCSC) and controllable shunt reactor(CSR)

This paper analyzes the fundamental frequency impedance presents a novel transmission line pilot protection scheme characteristic of a thyristor controlled series capacitor （TCSC） and based on fault component integrated impedance （FCII） calculated for a transmission line with TCSC and controllable shunt reactor （CSR）. The FCII is defined as the ratio of the sum of the fault component voltage phasors of a transmission line with TCSC and CSR to the sum of the fault component current phasors where all the phasors are determined at both line＇s terminals. It can be used to distinguish internal faults occurring on the line from external ones. If the fault is an external one the FCII reflects the line＇s capacitive impedance and has large value. If the fault is an internal one on the line the FCII reflects the impedance of the equivalent system and the line and is relatively small. The new pilot protection scheme can be easily set and has the fault phase selection ability and also it is not affected by the capacitive current and the fault transition resistance. It is not sensitive to compensation level and dynamics of TCSC and CSR. The effectiveness of the new scheme is validated against data obtained in ATP simulations and Northwest China 750 kV Project.