Transmission-line design: the ultimate load concept applied to the Java 500 kV transmission lines

1988 ◽  
Vol 2 (2) ◽  
pp. 63 ◽  
Author(s):  
A.B. Wood ◽  
R.I. Fair ◽  
R.J. Liptrot
2014 ◽  
Vol 1006-1007 ◽  
pp. 1005-1009
Author(s):  
Yao Jun Liu ◽  
Zhuo Li Guo ◽  
Hua Pu Chen

When the human to transmission line repair, many potential risks and fault will cannot be found in time, resulting in not by prior treatment measures to ensure the safety and reliability of the power supply. To realize the state overhaul transmission line, can reduce the blindness of maintenance, improve the transmission line operation stability and save a lot of manpower material resources. Transmission line state repair work there are many difficulties, so in the state overhaul transmission line, on the basis of elaborating the transmission line design condition maintenance expert system, in order to improve the transmission lines the state overhaul of work efficiency.


Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2474
Author(s):  
Jon T. Leman ◽  
Robert G. Olsen

Power system load growth and transmission corridor constraints are driving industry activity in the area of high surge impedance loading (HSIL). Examples include compact structure design and uprating existing transmission lines. Recent research relating electric field uniformity to transmission line capacity and critical flashover voltage underscored the need for better overvoltage data to quantify insulation margins for HSIL design. To that end, this work extends the finite difference time domain (FDTD) method with distributed corona losses to transmission lines with bundled conductors. The model was adapted for practical use in high-volume statistical transient simulation and applied to an example 500 kV line. Transients included line energization and trapped charge reclosing. Overvoltage profiles and statistical distributions were generated from 9500 simulations obtained by random breaker close timing and variation in line length and altitude. Distributed corona losses reduced 98th percentile line-to-ground switching overvoltages by 4%–14% of nominal. The estimated line-to-ground switching surge flashover probability was 54%–80% lower with corona loss. Corona had less impact on line-to-line overvoltages, but the effects were still notable. Results highlight the importance of considering detailed overvoltage profiles and accounting for corona loss attenuation when seeking to carefully quantify insulation design margins.


2020 ◽  
Vol 92 (2) ◽  
pp. 20502
Author(s):  
Behrokh Beiranvand ◽  
Alexander S. Sobolev ◽  
Anton V. Kudryashov

We present a new concept of the thermoelectric structure that generates microwave and terahertz signals when illuminated by femtosecond optical pulses. The structure consists of a series array of capacitively coupled thermocouples. The array acts as a hybrid type microwave transmission line with anomalous dispersion and phase velocity higher than the velocity of light. This allows for adding up the responces from all the thermocouples in phase. The array is easily integrable with microstrip transmission lines. Dispersion curves obtained from both the lumped network scheme and numerical simulations are presented. The connection of the thermocouples is a composite right/left-handed transmission line, which can receive terahertz radiation from the transmission line ports. The radiation of the photon to the surface of the thermocouple structure causes a voltage difference with the bandwidth of terahertz. We examined a lossy composite right/left-handed transmission line to extract the circuit elements. The calculated properties of the design are extracted by employing commercial software package CST STUDIO SUITE.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1561
Author(s):  
Hao Chen ◽  
Zhongnan Qian ◽  
Chengyin Liu ◽  
Jiande Wu ◽  
Wuhua Li ◽  
...  

Current measurement is a key part of the monitoring system for power transmission lines. Compared with the conventional current sensor, the distributed, self-powered and contactless current sensor has great advantages of safety and reliability. By integrating the current sensing function and the energy harvesting function of current transformer (CT), a time-multiplexed self-powered wireless sensor that can measure the power transmission line current is presented in this paper. Two operating modes of CT, including current sensing mode and energy harvesting mode, are analyzed in detail. Through the design of mode-switching circuit, harvesting circuit and measurement circuit are isolated using only one CT secondary coil, which eliminates the interference between energy harvesting and current measurement. Thus, the accurate measurement in the current sensing mode and the maximum energy collection in the energy harvesting mode are both realized, all of which simplify the online power transmission line monitoring. The designed time-multiplexed working mode allows the sensor to work at a lower transmission line current, at the expense of a lower working frequency. Finally, the proposed sensor is verified by experiments.


Author(s):  
Baina He ◽  
Yadi Xie ◽  
Jingru Zhang ◽  
Nirmal-Kumar C. Nair ◽  
Xingmin He ◽  
...  

Abstract In the transmission line, the series compensation device is often used to improve the transmission capacity. However, when the fixed series capacitor (FSC) is used in high compensation series compensation device, the stability margin cannot meet the requirements. Therefore, thyristor controlled series compensator (TCSC) is often installed in transmission lines to improve the transmission capacity of the line and the stability of the system. For cost considerations, the hybrid compensation mode of FSC and TCSC is often adopted. However, when a single-phase grounding fault occurs in a transmission line with increased series compensation degree, the unreasonable distribution of FSC and TCSC will lead to the excessive amplitude of secondary arc current, which is not conducive to rapid arc extinguishing. To solve this problem, this paper is based on 1000 kV Changzhi-Nanyang-Jingmen UHV series compensation transmission system, using PSCAD simulation program to established UHV series compensation simulation model, The variation law of secondary arc current and recovery voltage during operation in fine tuning mode after adding TCSC to UHV transmission line is analyzed, and the effect of increasing series compensation degree on secondary arc current and recovery voltage characteristics is studied. And analyze the secondary arc current and recovery voltage when using different FSC and TCSC series compensation degree schemes, and get the most reasonable series compensation configuration scheme. The results show that TCSC compensation is more beneficial to arc extinguishing under the same series compensation. Compared with several series compensation schemes, it is found that with the increase of the proportion of TCSC, the amplitude of secondary arc current and recovery voltage vary greatly. Considering various factors, the scheme that is more conducive to accelerating arc extinguishing is chosen.


2017 ◽  
Vol 12 (02) ◽  
pp. C02002-C02002
Author(s):  
R. Bates ◽  
C. Buttar ◽  
J. Buytaert ◽  
L. Eklund ◽  
L.F.S. de Acedo ◽  
...  

2012 ◽  
Vol 610-613 ◽  
pp. 2813-2818
Author(s):  
Xian Long Lu ◽  
Zeng Zhen Qian

This paper presents the concept and the fundamental issues and the development on the environmental geotechnology in transmission lines foundation engineering. Namely, environmental geotechnology and theory is to study the restriction effects of environment on the transmission line routes, foundation selection and reliability, to predict the results of transmission line foundation construction on the environment, and to study on countermeasures of environmental protection in transmission foundation engineering. And then, from the above three aspects, the design method combined strength and displacement for tower foundation, the selection on foundation types and technical scheme for transmission line tower, and the countermeasures for soil and water conservation, the author introduces the development and practice of environmental geotechnology for transmission lines foundation engineering in China.


2013 ◽  
Vol 805-806 ◽  
pp. 851-854
Author(s):  
Zhi Ge Jia ◽  
Zhao Sheng Nie ◽  
Wei Wang ◽  
Xiao Guan ◽  
Di Jin Wang

This work describes the field testing process of Global Navigation Satellite System (GNSS) receiver under 220KV, 500KV UHV transmission line and standard calibration field. Analysis for GNSS data results shows that the radio interference generated by EHV transmission lines have no effect on GNSS receiver internal noise levels and valid GNSS observation rate. Within 50 meters of the EHV transmission lines, the multi-path effects (mp1 and mp2 value) significantly exceeded the normal range and becomes larger with the increase of the voltage .outside 50 meters of the EHV transmission line, the multi-path effects have almost no effect on the high-precision GNSS observations.


2020 ◽  
Author(s):  
Enrique Rosales-Asensio ◽  
Antonio Colmenar-Santos ◽  
José-Carmelo Rosales

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