• Title/Summary/Keyword: Overhead Transmission Line

Search Result 216, Processing Time 0.024 seconds

Effects of Reclosing for Insulation Coordination in 345kV Combined Transmission Lines (345kV 혼합송전선로에서 재폐로가 절연설계에 미치는 영향)

  • Lee, Jong-Beom;Jung, Chae-Kyun;Lim, Kwang-Sik;Kang, Ji-Won
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.59 no.5
    • /
    • pp.847-853
    • /
    • 2010
  • This paper describes switching surge analysis for reclosing decision in 345kV combined transmission line with XLPE power cable. Reclosing operation should be decided based on the detailed technical analysis in combined transmission line because this line includes power cable section which is week on insulation. Insulation of power cable can be breakdown at the week point in case of reclosing moment. Therefore the detailed analysis has to be carried out by considering several conditions such as length ratio of power cable section, arrestor, inserting resistance, charging rate, grounding resistance, etc.. On the other hand sheath voltage on IJ(Insulated Joint) is analyzed to check dangerous condition on cable cover. Analysis is performed by EMTP/ATP. Analysis results show that reclosing can be operated as the single line-to-ground fault occurs on overhead line in 345kV combined transmission line, if the inserting resistance is considered before the operation of main circuit breaker.

Effect of Phase Arrangement on Magnetic Field of Overhead Transmission Lines (송전선로의 상배열이 자계 크기에 미치는 영향)

  • Kim, Sang-Beom;Lee, Dong-Il;Shin, Koo-Yong;Kim, Jeong-Soo
    • Proceedings of the KIEE Conference
    • /
    • 1998.07e
    • /
    • pp.1678-1680
    • /
    • 1998
  • The purpose of this study is to obtain optimum arrangement of phase conductors in minimizing magnetic field from overhead transmission lines. Data of the transmission lines rated 345 kV of the KEPCO(Korea Electric Power Company)'s system were used. For a three phase-double circuit transmission line, low-reactance arrangement is optimum in minimizing magnetic fields. For a three phase-four circuit, optimum phase arrangement is a-b-c-b-a-c(lower two circuits, clockwise)/b-c-a-c-a-b(upper two circuits, clockwise).

  • PDF

A Study on the Swing Analysis and Application of Suspension Insulating Sets and Jumper wires for 154kV and 345kV Overhead Lines (345kV이하 송전선로용 현수애자련 및 점퍼선의 횡진해석 및 적용연구)

  • Sohn, H.K.;Lee, E.W.
    • Proceedings of the KIEE Conference
    • /
    • 2001.04a
    • /
    • pp.116-118
    • /
    • 2001
  • It is important to determine of tower type whether suspension or tension tower in overhead transmission lines. When we select to tower type, we have need to check of swing angle for suspension string sets. And jumper wire of T/L in the strong wind area have to analysis of swing angle in order to clearance or length of tower arms. This paper is summarized the methods to calculate of swing angle for suspension string sets and jumper wires, and is calculated the swing angle. The calculated result have proposed to improved design specifications of overhead transmission line.

  • PDF

Collapse simulations of a long span transmission tower-line system subjected to near-fault ground motions

  • Tian, Li;Pan, Haiyang;Ma, Ruisheng;Qiu, Canxing
    • Earthquakes and Structures
    • /
    • v.13 no.2
    • /
    • pp.211-220
    • /
    • 2017
  • Observations from past strong earthquakes revealed that near-fault ground motions could lead to the failure, or even collapse of electricity transmission towers which are vital components of an overhead electric power delivery system. For assessing the performance and robustness, a high-fidelity three-dimension finite element model of a long span transmission tower-line system is established with the consideration of geometric nonlinearity and material nonlinearity. In the numerical model, the Tian-Ma-Qu material model is utilized to capture the nonlinear behaviours of structural members, and the cumulative damage D is defined as an index to identify the failure of members. Consequently, incremental dynamic analyses (IDAs) are conducted to study the collapse fragility, damage positions, collapse margin ratio (CMR) and dynamic robustness of the transmission towers by using twenty near-fault ground motions selected from PEER. Based on the bending and shear deformation of structures, the collapse mechanism of electricity transmission towers subjected to Chi-Chi earthquake is investigated. This research can serve as a reference for the performance of large span transmission tower line system subjected to near-fault ground motions.

Dynamic Thermal Rating of Transmission Line Based on Environmental Parameter Estimation

  • Sun, Zidan;Yan, Zhijie;Liang, Likai;Wei, Ran;Wang, Wei
    • Journal of Information Processing Systems
    • /
    • v.15 no.2
    • /
    • pp.386-398
    • /
    • 2019
  • The transmission capacity of transmission lines is affected by environmental parameters such as ambient temperature, wind speed, wind direction and so on. The environmental parameters can be measured by the installed measuring devices. However, it is impossible to install the environmental measuring devices throughout the line, especially considering economic cost of power grid. Taking into account the limited number of measuring devices and the distribution characteristics of environment parameters and transmission lines, this paper first studies the environmental parameter estimating method of inverse distance weighted interpolation and ordinary Kriging interpolation. Dynamic thermal rating of transmission lines based on IEEE standard and CIGRE standard thermal equivalent equation is researched and the key parameters that affect the load capacity of overhead lines is identified. Finally, the distributed thermal rating of transmission line is realized by using the data obtained from China meteorological data network. The cost of the environmental measurement device is reduced, and the accuracy of dynamic rating is improved.

Lifetime estimation of a covered overhead line conductor

  • Leskinen, Tapio;Kantola, Kari
    • Wind and Structures
    • /
    • v.6 no.4
    • /
    • pp.307-324
    • /
    • 2003
  • The paper presents results of studies concerning wind-induced aeolian vibration and fatigue of a 110 kV covered conductor overhead line. Self-damping measurement techniques are discussed: power method is found to be the most reliable technique. A method for compensating tension variations during the self-damping test is presented. Generally used empirical self-damping power models are enhanced and the different models are compared with each other. The Energy Balance Analysis (EBR) is used to calculate the aeolian vibration amplitudes, which thereafter are converted to bending stress for the calculation of conductor lifetime estimate. The results of EBA are compared with field measurements, Results indicate that adequate lifetime estimates are produced by EBA as well as field measurements. Generally the EBA gives more conservative lifetime expectancy. This is believed to result from the additional damping existing in true suspension structures not taken into account by EBA. Finally, the correctness of the line design is verified using Cigre's safe design tension approach.

Impedance measurement and analysis of overhead medium voltage power lines for broad band power line communication (BPLC) ($1{\sim}30MHz$ 광대역 전력선 통신을 위한 고압 배전선의 임피던스 특성 측정 및 해석)

  • Park, Young-Jin;Lee, Jae-Jo;Kim, Kwan-Ho;Lee, Won-Tae
    • Proceedings of the KIEE Conference
    • /
    • 2005.07c
    • /
    • pp.2345-2347
    • /
    • 2005
  • In this paper, impedance characteristics of overhead medium-voltage (MV) power lines is reported for power line communication (PLC) over an MV power line network. For analysis, a two-port equivalent network model of MV power lines is derived. By applying the transmission line theory, reflection behavior and impedance of power lines are investigated. For verification, impedance of power lines is measured at a test field for an MV PLC. The results show that impedance of MV power lines is between $200{\Omega}$ and $300{\Omega}$ and converges to a half of their characteristic impedance.

  • PDF

A Study on Reclosing Decision on 154kV Combined Transmission Lines (154kV 혼합송전선로 재폐로 결정에 관한 연구)

  • Jung, Chae-Kyun;Park, Hung-Sok;Kang, Ji-Won;Lee, Jong-Beom
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.59 no.10
    • /
    • pp.1761-1769
    • /
    • 2010
  • This paper describes switching surge analysis on reclosing decision in 154kV combined transmission line with power cables. Reclosing should be operated in combined transmission line based on the technical evaluation because of insulation problem of power cable section. If the surge strikes on power cable, the breakdown can occur at week point of cable insulation. Therefore the detailed analysis is required by considering several conditions such as length ratio of power cable, arrester, fault resistance, charging rate and grounding resistance, etc.. In addition, sheath voltage on IJ(Insulated Joint) is analyzed to confirm the protective level. Simulation is performed by EMTP/ATP. Analysis results show that reclosing can be operated without any special problem by the single line-to-ground fault with fault resistance of $1\Omega$ to $50\Omega$ occurred at the overhead transmission section in 154kV combined transmission lines and trap charge of 100% and 110%.

Development of the Self-Build based Emergency Towers for Overhead Transmission Line (송전선로 비상복구용 자주조립식 철주 개발)

  • Byun Gang;Min Byeong Wook;Wi Hwa Bog;Park Jae Ung;Baek Soo Gon
    • Proceedings of the KIEE Conference
    • /
    • summer
    • /
    • pp.494-496
    • /
    • 2004
  • Due to a typhoon named MAEMI on Sep12, 2004, 7 transmission towers collapsed and 3 were damaged in the Gyeongnam and Busan areas. These caused long-term black-outs in Goeje-do. When a transmission tower collapses or is damaged, Construction will take more than 2 months and this will be accompanied by long-term black-outs. Therefore a temporary iron pole is used in such emergencies. Current temporary rehabilitation angle steel iron Pole consistes of around 800 members, 2,800 bolts and it takes about 5 days to construct a temporary transmission line. Consiquently wide black-outs occur during the construction of the temporary transmission line. To reduce black-out time, the construction period must be reduced as much as possible. This paper presents new methods to reduce temporary transmission line construction time to within 48 hours by applying a self-reliance assembling method instead of the current man power assembling method and by modulizing each angle steel with duralumin.

  • PDF