scholarly journals Dynamic Rating Management of Overhead Transmission Lines Operating under Multiple Weather Conditions

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1136
Author(s):  
Raquel Martinez ◽  
Mario Manana ◽  
Alberto Arroyo ◽  
Sergio Bustamante ◽  
Alberto Laso ◽  
...  
Keyword(s):  
Transmission Lines ◽  
Weather Conditions ◽  
High Accuracy ◽  
Power Lines ◽  
Calculation Error ◽  
Practical Application ◽  
Estimation Errors ◽  
Temperature Calculation ◽  
Overhead Transmission Lines ◽  
Economic Constraints

Integration of a large number of renewable systems produces line congestions, resulting in a problem for distribution companies, since the lines are not capable of transporting all the energy that is generated. Both environmental and economic constraints do not allow the building new lines to manage the energy from renewable sources, so the efforts have to focus on the existing facilities. Dynamic Rating Management (DRM) of power lines is one of the best options to achieve an increase in the capacity of the lines. The practical application of DRM, based on standards IEEE (Std.738, 2012) and CIGRE TB601 (Technical Brochure 601, 2014) , allows to find several deficiencies related to errors in estimations. These errors encourage the design of a procedure to obtain high accuracy ampacity values. In the case of this paper, two methodologies have been tested to reduce estimation errors. Both methodologies use the variation of the weather inputs. It is demonstrated that a reduction of the conductor temperature calculation error has been achieved and, consequently, a reduction of ampacity error.

scholarly journals Transient Temperature Calculation and Multi-Parameter Thermal Protection of Overhead Transmission Lines Based on an Equivalent Thermal Network

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 67 ◽  
Author(s):  
Jian Hu ◽  
Xiaofu Xiong ◽  
Jing Chen ◽  
Wei Wang ◽  
Jian Wang
Keyword(s):  
Power System ◽  
Transmission Line ◽  
Transmission Lines ◽  
Calculation Method ◽  
Thermal Protection ◽  
Transient Temperature ◽  
Accurate Analysis ◽  
Temperature Calculation ◽  
Overhead Transmission Lines ◽  
Thermal Network

The overload degree of a transmission line is represented by currents in traditional overload protection, which cannot reflect its safety condition accurately. The sudden rise in transmission line current may lead to cascading tripping under traditional protection during power flow transfer in a power system. Therefore, timely and accurate analysis of the transient temperature rise of overhead transmission lines, revealing their overload endurance capability under the premise of ensuring safety, and coordination with power system controls can effectively eliminate overloading. This paper presents a transient temperature calculation method for overhead transmission lines based on an equivalent thermal network. This method can fully consider the temperature-dependent characteristics with material properties, convective heat resistance, and radiation heat and can accurately calculate the gradient distribution and response of the conductor cross-section temperature. The validity and accuracy of the proposed calculation method are verified by a test platform. In addition, a multi-parameter thermal protection strategy is proposed on the basis of the abovementioned calculation method. The protection can adequately explore the maximum overload capability of the line, and prevent from unnecessary tripping to avoid the expansion of accidents. Finally, the validity of the proposed protection is verified by the modified 29-bus system.

On the vibration analysis of power lines with moving dampers

2017 ◽  
Vol 24 (18) ◽  
pp. 4096-4109 ◽  
Author(s):  
MA Bukhari ◽  
O Barry ◽  
E Tanbour
Keyword(s):  
Transmission Lines ◽  
Equations Of Motion ◽  
Power Lines ◽  
Governing Equations ◽  
Wind Force ◽  
Vibration Displacement ◽  
Mass System ◽  
Overhead Transmission Lines ◽  
Parametric Studies ◽  
Mass Spring

This work investigates the performance of a moving damper for overhead transmission lines. The damper or absorber consists of mass-spring-damper-mass system. The absorber is connected to a single conductor subjected to pretension and wind force. The governing equations of motion are obtained using Hamilton’s principle, and numerical analysis is carried out using MATLAB®. The model is validated by comparing the present results to those in the literature. Parametric studies are conducted to investigate the performance of the proposed absorber. The results indicate that a moving absorber can be more effective than a fixed absorber. It is also demonstrated that the vibration displacement decreases with increasing forcing frequency and decreasing absorber speed.

Probabilistic Index for Increasing Hourly Transmission Line Ratings

2007 ◽  
Vol 8 (4) ◽  
Author(s):  
Antonio Bracale ◽  
Amedeo Andreotti ◽  
Guido Carpinelli ◽  
Umberto De Martinis
Keyword(s):  
Transmission Lines ◽  
Weather Conditions ◽  
Weather Data ◽  
Time Series Models ◽  
Overhead Transmission Lines ◽  
Current Limit ◽  
Weather Parameters ◽  
Limit Probability ◽  
Bayesian Time Series ◽  
Probability Density Function Pdf

The steady state thermal rating of overhead transmission lines is limited by the conductor`s maximum design temperature, which is related to the maximum sag and the loss of tensile strength of the conductors. Traditionally, this overhead transmission lines rating is computed using a deterministic approach, with reference to severe weather conditions. Thus, the application of this method leads to conservative results resulting in under-utilization of conductors. In this paper, a new method based on an hourly probabilistic index is proposed to predict the line thermal rating for each hour of the day; this index is evaluated using the conductor current limit probability density function (pdf). The method uses Bayesian time series models for the weather parameters (ambient temperature, wind speed and wind direction) and calculates the conductor current limit pdf using a Monte Carlo simulation. The probabilistic index is applied by considering measured weather data of both hot and cold seasons; the corresponding lines ratings are reported and analyzed.

scholarly journals Coupling Between Separate Phases of Coaxial Double Circuit Transmission Lines

1988 ◽  
Vol 13 (2) ◽  
pp. 85-111
Author(s):  
M. Hamed
Keyword(s):  
Phase Shift ◽  
Transmission Lines ◽  
Magnetic Field Intensity ◽  
Mutual Effect ◽  
Mutual Inductance ◽  
Power Lines ◽  
Overhead Transmission Lines ◽  
External Point ◽  
The Magnetic Field ◽  
Circuit Power

The paper studies the so-called coaxial overhead transmission lines. The concentric phases are considered. The mathematical analysis for voltage and current is presented. The telegraphic equations of the double circuit power lines with the mutual effect between circuits are introduced. The condition for single circuit transmission line is checked. The mutual effect between both circuits is studied on the basis of the ratio between the two currents of both circuits. The appeared phase shift between the two vectors of currents is inserted in the investigation. The magnetic field intensity at an external point of a line is mathematically expressed. Its value is approximated for the purpose of zero mutual inductance between phases of the same circuit. The mutual inductance between the two nearest groups of phases due to the linkage flux for the studied line is formulated. Its dependency on the distance from the phases as well as on the ratio of currents of both circuits is analysed. Then, the effect of phase shift on the mutual inductance is investigated. An idea for the control of the ratio between currents of both circuits of a line is presented.

Rational Damping Arrangement Design for Transmission Lines Vibrations: Analytical and Experimental Analysis

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
O. Barry ◽  
R. Long ◽  
D. C. D. Oguamanam
Keyword(s):  
Explicit Expression ◽  
Transmission Lines ◽  
Experimental Analysis ◽  
Power Lines ◽  
Rational Approach ◽  
Loop Length ◽  
Overhead Transmission Lines ◽  
Experimental Approaches ◽  
First Time ◽  
Good Agreement

The control of overhead transmission lines vibrations is achieved by Stockbridge dampers. However, the effectiveness of the damper is significantly dependent on its location on the conductor. This paper studies the arrangement of Stockbridge dampers on power lines vibrations using both analytical and experimental approaches. An explicit expression of the loop length is presented for the first time. This expression is used to determine the optimal damper location based on a rational approach. The effectiveness of the proposed approach is validated numerically and experimentally. The results show very good agreement and indicate that Stockbridge dampers are more effective for asymmetrical damping arrangement with the bigger counterweight oriented toward the tower.

scholarly journals HTLS Conductors: A Way to Optimize RES Generation and to Improve the Competitiveness of the Electrical Market—A Case Study in Sicily

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
M. G. Ippolito ◽  
F. Massaro ◽  
C. Cassaro
Keyword(s):  
Transmission Lines ◽  
Renewable Energy Sources ◽  
Operating Conditions ◽  
Power Lines ◽  
Environmental Constraints ◽  
Electrical Systems ◽  
Overhead Transmission Lines ◽  
Electricity System ◽  
New Energy

Stringent environmental constraints make more difficult to identify new energy corridors and build new power lines. The increase in the generation of electricity from renewable energy sources (RESs) makes the operation of electrical systems increasingly difficult in some areas. The transmission system operators (TSOs), in Italy Terna, are forced to exploit the existing overhead transmission lines, increasing the possibility of dispatching energy, in particular RES, optimizing the transmission capacity. Therefore, after a brief presentation of the Sicilian electricity system and a brief description of high-temperature low-sag (HTLS) conductors, a case study is presented. It is shown how it is possible to optimize the dispatching from renewable sources and, finally, it is demonstrated how the use of HTLS conductor can contribute, together with other actions taken by the TSO, to the decrease of the zonal price of electricity, to the creation of a market with fewer constraints and to new operating conditions that increase the resilience of the electricity system in case of disturbances.

scholarly journals Calibration of Dynamic Line Rating Model for Phasor Measurement Unit Based Wide Area Measurement System in Smart Grid Application

2019 ◽  
Vol 8 (4) ◽  
pp. 1879-1883 ◽  
Keyword(s):  
Transmission Lines ◽  
System Analysis ◽  
Weather Conditions ◽  
Area Measurement ◽  
Wide Area ◽  
Measurement Unit ◽  
Overhead Transmission Lines ◽  
Phasor Measurement ◽  
Rating Model ◽  
Thermal Line

The inefficiency of power transmission lines always becoming an issue in power system analysis. One of the most applicable methods Dynamic Thermal Current Rating (DTCR) to measure the thermal line ratings of existing transmission lines. This DTCR system operated through Phasor Measurement Units (PMUs) in Wide Area Measurement (WAM) system of the Sarawak Energy. To calculate the line rating based on measured or predicted weather conditions of the overhead transmission lines. However, the existing DTCR system of Sarawak Energy facing several accuracy issues. Therefore, this paper intended to perform an extended study on the sensitivity analysis of conductors in overhead transmission lines using the dynamic thermal rating model. The parameters (wind speed, the density of air, solar radiation) that influence the thermal line ratings considered in measuring, assessing the conductors’ thermal effects and then these parameters were considered for the line rating models that dynamically will adjust the weather information of the conductor in overhead transmission lines on WAM systems. The performance of this study carried out using Matlab based simulation. The result shows that the proposed model that uses the dynamic factors brings the expected outcome in measuring the accurate ratings of the overhead transmission lines.

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