Dynamic response of transmission lines guyed towers under wind loading

2010 ◽  
Vol 37 (3) ◽  
pp. 450-465 ◽  
Author(s):  
F. Gani ◽  
F. Légeron
Keyword(s):  
Dynamic Response ◽  
Direct Current ◽  
Transmission Lines ◽  
Wind Loading ◽  
Dynamic Effects ◽  
Transient Dynamic ◽  
Simplified Method ◽  
Loading Case ◽  
Dc Line ◽  
Guyed Towers

The importance of the dynamic response of guyed towers for transmission lines (TLs) under wind loading is evaluated in this article. The objective is to verify if the simplified static-equivalent approach provided in the current TL codes is sufficient for this type of flexible tower. As a comparison, transient dynamic (TD) analyses were performed. Two different guyed tower configurations were investigated: (i) the direct current (DC) line and (ii) the alternating current (AC) line. Loading cases considering bare and iced TL structures were studied. It was found that, depending on the guyed tower configuration and the loading case, the static-equivalent approach may underestimate the possible dynamic response. In addition, a simplified method that allows a better prediction of the dynamic effects is proposed.

scholarly journals Dynamic response due to cable rupture in a transmission lines guyed towers

2017 ◽  
Vol 199 ◽  
pp. 116-121 ◽  
Author(s):  
Thiago B. Carlos ◽  
João Kaminski Jr.
Keyword(s):  
Dynamic Response ◽  
Transmission Lines ◽  
Guyed Towers

scholarly journals A Novel Pilot Protection Principle Based on Modulus Traveling-Wave Currents for Voltage-Sourced Converter Based High Voltage Direct Current (VSC-HVDC) Transmission Lines

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2395 ◽  
Author(s):  
Xiangyu Pei ◽  
Guangfu Tang ◽  
Shengmei Zhang
Keyword(s):  
High Voltage ◽  
Direct Current ◽  
Transmission Lines ◽  
Traveling Wave ◽  
Hvdc Transmission ◽  
High Voltage Direct Current ◽  
Hvdc Transmission Lines ◽  
Dc Line ◽  
Voltage Sourced Converter ◽  
Pilot Protection

Protection for transmission lines is one of crucial problems that urgently to be solved in constructing the future high-voltage and large-capacity voltage-sourced converter based high voltage direct current (VSC-HVDC) systems. In order to prevent the DC line fault from deteriorating further due to the failure of main protection, a novel pilot protection principle for VSC-HVDC transmission lines is proposed in this paper. The proposed protection principle is based on characteristics of modulus traveling-wave (TW) currents. Firstly, the protection starting-up criterion is constructed by using the absolute value of the 1-mode TW current gradient. Secondly, the fault section identification is realized by comparing the polarities of wavelet transform modulus maxima (WTMM) of 1-mode initial TW currents acquired from both terminals of the DC line. Then, the selection of fault line is actualized according to the polarity of WTMM of local 0-mode initial reverse TW current. A four-terminal VSC-based DC grid electromagnetic transient model based on the actual engineering parameters is built to assess the performance of the proposed pilot protection principle. Simulation results for different cases prove that the proposed pilot protection principle is excellent in reliability, selectivity, and robustness. Moreover, the data synchronization is not required seriously. Therefore, the proposed novel pilot protection principle can be used as a relatively perfect backup protection for VSC-HVDC transmission lines.

scholarly journals Stability Improvement of The Iraqi Super Grid (400kV) using High Voltage Direct Current (HVDC) Transmission

2021 ◽  
Vol 27 (11) ◽  
pp. 64-74
Author(s):  
Zainab Nadhim Abbas ◽  
Firas Mohammed Tuaimah
Keyword(s):  
High Voltage ◽  
Direct Current ◽  
Transmission Lines ◽  
Short Circuit ◽  
Alternating Current ◽  
National Network ◽  
Hvdc Transmission ◽  
High Voltage Direct Current ◽  
Dc Line ◽  
Bipolar Type

This research analyzes the level of the short circuit effect of the Iraqi super network and decides the suitable location for the High Voltage Direct Current (HVDC) connections in order to obtain the best short circuit reduction of the total currents of the buses in the network. The proposed method depends on choosing the transmission lines for Alternating current (AC) system that suffers from high Short Circuit Levels (SCLs) in order to reduce its impact on the transmission system and on the lines adjacent to it and this after replacing the alternating current (AC) line by direct current (DC) line. In this paper, Power System Simulator for Engineering (PSS/E) is used to model two types of HVDC lines in an effective region of Iraqi networks and to perform comparative studies to test the location of Short Circuit Levels (SCLs) between an actual AC and AC/DC case study in a portion of the Iraqi national network. The results proved the effectiveness of this method in eliminating severe faults and unwanted short currents, and the results showed that the bipolar type is better in reducing Short Circuit Levels of the Iraqi network.

A comparison of the gust factor method and the patch load method of analysis of guyed towers

1996 ◽  
Vol 23 (4) ◽  
pp. 862-871 ◽  
Author(s):  
Robert G. Selby ◽  
Robert B. Dryburgh
Keyword(s):  
Dynamic Method ◽  
Wind Loading ◽  
Dynamic Effects ◽  
Gust Factor ◽  
Parametric Studies ◽  
Patch Load ◽  
Load Analysis ◽  
Guyed Towers ◽  
Tower Height ◽  
Supporting Structures

The Canadian standard CAN/CSA-S37-94 "Antennas, towers and antenna supporting structures" (S37) has introduced as an appendix a quasi-dynamic method of analysis. This patch load method yields a more realistic pattern of forces in a guyed tower, but S37 contains no firm guidelines as to when this new method is required over the conventional static gust factor approach. This paper describes various comparative studies that were made to determine the conditions under which the normally used gust factor approach does not give sufficiently acceptable results so that patch load analyses are required. Results of the parametric studies and the analyses of a large number of actual towers showed that leg loads in the upper few spans tended to be about 15% larger on average in a patch load analysis. Face shears at the guy supports were also about 15% higher on average in the patch load method. The studies revealed no strong trends between the patch load and gust factor correlation and the tower parameters, although there were slight trends suggesting that a patch load analysis was warranted if the tower height was greater than 250 m, the aspect ratio was greater than 120, or the drag area exceeded 2.0 m2/m. The presence of a cantilever accentuated the margin between the results of the two methods. Key words: guyed towers, analysis, wind loading, dynamic effects, patch load, gust factor.

scholarly journals Global experience of HVDC composite insulators in outdoor and indoor environment

2020 ◽  
Vol 59 (1) ◽  
pp. 606-618
Author(s):  
Mohammad Akbar ◽  
Basharat Mehmood
Keyword(s):  
High Voltage ◽  
Direct Current ◽  
Transmission Lines ◽  
Power Transmission ◽  
Green Energy ◽  
Attractive Alternative ◽  
Hvdc Transmission ◽  
Ceramic Insulators ◽  
High Power Transmission ◽  
Aging Performance

AbstractHigh-voltage direct current (HVDC) transmission is known as green-energy transfer technology and has recently become an attractive alternative of high-voltage alternating current (HVAC) due to its high-power transmission capability and lower power loss. Use of composite insulators on direct current (DC) transmission lines experienced rapid growth in recent years due to their high hydrophobicity and better performance in contaminated environment than conventional ceramic insulators. During their service operation on DC lines, insulators are prone to more accumulation of contaminants due to unidirectional electric field. The contaminants under wet conditions allow leakage current to flow on the insulator surface. Being organic in nature, polymeric insulators have a tendency to age under the combined effects of electrical and environmental stresses. To fully understand the long-term aging performance of DC composite insulators, a detailed survey was considered necessary. Towards that end, this paper critically summarizes worldwide experience of aging performance of composite insulators in the field as well as in laboratory conditions.

scholarly journals Locating Faults in Thyristor-Based LCC-HVDC Transmission Lines Using Single End Measurements and Boosting Ensemble

Electronics ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 186
Author(s):  
Aleena Swetapadma ◽  
Shobha Agarwal ◽  
Satarupa Chakrabarti ◽  
Soham Chakrabarti ◽  
Adel El-Shahat ◽  
...  
Keyword(s):  
Direct Current ◽  
Transmission Lines ◽  
Fault Location ◽  
Ensemble Method ◽  
Percentage Error ◽  
Communication Link ◽  
Half Cycle ◽  
Optimal Method ◽  
Hvdc Transmission ◽  
Hvdc Transmission Lines

Most of the fault location methods in high voltage direct current (HVDC) transmission lines usemethods which require signals from both ends. It will be difficult to estimate fault location if the signal recorded is not correct due to communication problems.Hence a robust method is required which can locate fault with minimum error. In this work, faults are located using boosting ensembles in HVDC transmission lines based on single terminal direct current (DC) signals. The signals are processed to obtain input features that vary with the fault distance. These input features are obtained by taking maximum of half cycle current signals after fault and minimum of half cycle voltage signals after fault from the root mean square of DC signals. The input features are input to a boosting ensemble for estimating the location of fault. Boosting ensemble method attempts to correct the errors from the previous models and find outputs by combining all models. The boosting ensemble method has been also compared with the decision tree method and thebagging-based ensemble method. Fault locations are estimated using three methods and compared to obtain an optimal method. The boosting ensemble method has better performance than all the other methods in locating the faults. It also validated varying fault resistance, smoothing reactors, boundary faults, pole to ground faults and pole to pole faults. The advantage of the method is that no communication link is needed. Another advantage is that it allowsreach setting up to 99.9% and does not exhibitthe problem of over-fitting. Another advantage is that the percentage error in locating faults is within 1% and has a low realization cost. The proposed method can be implemented in HVDC transmission lines effectively as an alternative to overcome the drawbacks of traveling wave methods.

Sign in / Sign up

Export Citation Format

Share Document