scholarly journals Similarity Criteria of EHF Physical Model of Long Distance Transmission Line with Plate Phases

1988 ◽  
Vol 13 (1) ◽  
pp. 7-18
Author(s):  
M. Hamed
Keyword(s):  
Transmission Line ◽  
Physical Model ◽  
Transmission Lines ◽  
Power Transmission ◽  
Similarity Criteria ◽  
Long Distance ◽  
Potential Coefficient ◽  
Overhead Transmission Line ◽  
Long Distance Transmission ◽  
Independent Parameters

Carson's equations for computation of frequency dependent parameters of overhead transmission line are modified. The earth is considered to be homogenous. The optimal required number of terms of Carson's series for applications on computer is determined. Accurate mathematical expressions for resistance and inductance of overhead transmission lines are obtained.Different arrangements of conductors for double circuit transmission lines are studied. The mutual inductance and potential coefficient (mutual capacitance) of such arrangements are computed. Double voltage class type double circuit transmission lines are suggested. The plate type double circuit lines are proposed for power transmission over long distances.This paper presents a mathematical analysis in order to determine the coefficients of similarity criteria of EHF physical model for the given long distance transmission line. The integral analogue method and PI-theorem are used. The independent parameters of EHF physical model are formulated. The scales of four independent parameters of the designed EHF physical model are obtained.

scholarly journals STUDY OF VOLTAGE MODE IN THE LONG-DISTANCE AC TRANSMISSION LINE

2021 ◽  
Vol 2021 (59) ◽  
pp. 43-55
Author(s):  
T.L. Katsadze ◽  
◽  
D.V. Nastenko ◽  
O.M. Panienko ◽  
O.M. Iankovska ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Transmission Line ◽  
Extreme Point ◽  
Transmission Lines ◽  
Power Transmission ◽  
Voltage Distribution ◽  
Long Distance ◽  
Third Order ◽  
Long Distance Transmission ◽  
Wide Range

The charging currents of EHV transmission lines cause the Ferranti effect, which causes an increase in voltage at intermediate points transmission line. The work aims to study the laws of the voltage distribution along the line route and to develop a method for determining the coordinates of a point with extreme voltage. Methodology. Mathematical modeling of long-distance transmission lines in Wolfram Mathematica allowed to form the laws of the voltage distribution along the line and determine the coordinate of the extreme point on the voltage. Results. It is shown that the application of the traditional model of idealized power transmission causes high modeling accuracy only in the modes of unloaded line and low loads. In the range of medium and high loads, the simulation error reaches unacceptably large values. The paper proposes more accurate models for determining the coordinate of an extreme voltage point: linearized and second- and third-order models. It is shown that the proposed models are characterized by higher accuracy in a wide range of loads. Increasing the degree of the model results in higher accuracy, but is associated with an increase in the cumbersomeness of the mathematical model. It is shown that first and second-order models provide sufficient accuracy for typical designs of 750 kV power transmission lines. It is shown that neglecting the losses on the corona has almost no effect on the accuracy of calculating the coordinates of the extreme point on the voltage, which simplifies the linear calculation model and models of the second and third-order. Originality. Mathematical models of the first, second and third orders have been developed for high-precision determination of the coordinate of a voltage-extreme point along a long-distance transmission line. Practical significance. The offered mathematical models are intended for application in problems of regulation and adjustment of parameters of flexible power transmissions. Ref. 12, figure, tables 4.

scholarly journals Distribution of Magnetic Field in 400 kV Double-Circuit Transmission Lines

2020 ◽  
Vol 10 (9) ◽  
pp. 3266 ◽  
Author(s):  
Ramūnas Deltuva ◽  
Robertas Lukočius
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Transmission Line ◽  
Magnetic Field Strength ◽  
Transmission Lines ◽  
Power Transmission ◽  
Power Transmission Line ◽  
Overhead Transmission Line ◽  
The City ◽  
The Magnetic Field

A high-voltage AC double-circuit 400 kV overhead power transmission line runs from the city of Elk (Poland) to the city of Alytus (Lithuania). This international 400 kV power transmission line is potentially one of the strongest magnetic field-generating sources in the area. This 400 kV voltage double-circuit overhead transmission line and its surroundings were analyzed using the mathematical analytical methods of superposition and reflections. This research paper includes the calculation of the numerical values of the magnetic field and its distribution. The research showed that the values of the magnetic field strength near the international 400 kV power transmission line exceed the threshold values permitted by relevant standards. This overhead power line is connected to the general (50 Hz) power system and generates a highly intense magnetic field. It is suggested that experimental trials should be undertaken in order to determine the maximum values of the magnetic field strength. For the purpose of mitigating these values, it is suggested that the height of the support bars should be increased or that any individual and commercial activities near the object under investigation should be restricted.

Based on the TLM Method 1000kV UHV Transmission Line Performance Analysis

2011 ◽  
Vol 383-390 ◽  
pp. 2917-2922
Author(s):  
Feng Xia Li ◽  
Yue Long Wang
Keyword(s):  
Performance Analysis ◽  
Transmission Line ◽  
Transmission Lines ◽  
Power Transmission ◽  
Transmission Power ◽  
Long Distance ◽  
Transmission Distance ◽  
Transmission Line Modeling ◽  
Tlm Method ◽  
Ac Transmission

The TLM model of 3 - phase pow er t ran sm ission line is developed. Appling the transmission line modeling (TLM) method to analysis 1000kV ultrahigh voltage( UHV) AC transmission line, the obtained results prove that it is economical and reasonable to transmit the natural power by power transmission, and the transmission lines is a long-distance transmission power ; but both the super power and the power transmission, the transmission power reduce with the increase of transmission distance.

scholarly journals Corona Loss Minimization on High Voltage Transmission Line Network using Bundled Conductors.

2020 ◽  
Vol 9 (3) ◽  
pp. 887-891
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Power Transmission ◽  
Hessian Matrix ◽  
Electrical Power ◽  
Power Transmission Lines ◽  
Long Distance ◽  
Power Stations ◽  
Line Network ◽  
Corona Losses

Electrical power generated and transmitted at a long distance away from the power stations is usually affected by inherent transmission line losses. The Ohmic and Corona losses which are predominantly common in power transmission lines are considered in this paper. These two losses are mathematically modeled with and without embedded bundled conductors. The resultant model which is a non-linear multivariable unconstrained optimized equation is minimized using the Hessian matrix determinant method for stability test purposes. The results obtained show that corona losses are minimized with embedded bundled conductors at a very low current value with large spacing distance between the bundled conductors. The decrease in the corona loss which is a consequence of spacing adjustment of the 2, 3, and 4 strands of bundled conductors was plotted using MATLAB 7.14. The plots obtained are in conformity with the inverse relation between corona loss and conductor spacing.

scholarly journals Soft Computing Methods for Fault Detection in Power Transmission Lines

2019 ◽  
Vol 9 (1S3) ◽  
pp. 246-250
Keyword(s):  
Fault Detection ◽  
Transmission Line ◽  
Transmission Lines ◽  
Power Transmission ◽  
Computing Methods ◽  
Time Domain Reflectometry ◽  
Detection Methods ◽  
Physical Factors ◽  
Power Transmission Lines ◽  
Overhead Transmission Line

Communication is a major aspect of our day to day life and for maintaining the transmission of the data; electric power transmission lines play a major role in acting as the medium for this transmission. The transmission lines can further be differentiated as an overhead transmission line and underground transmission line. But the transmission is often hindered by the physical factors or generally known as faults. In the past few years, the implementation of the underground cable has seen an upsurge as these cables are not easily affected by the physical factors as the overhead cables are, as a result, there have been various methods adopted by the engineers for the analysis, detection and control of these faulty lines. Depending on the supply range of a particular nation different materials are used for the transmission lines. Different fault detection methods are used for the exact location of the fault and implementing that in a digitized way is the optimum solution. Whenever there is a fault the entire transmission line is affected, to ensure that the safety of the transmission line a governing system has been implied in our proposed work. Locating a fault requires various detection methods, one such method is the time domain reflectometry (TDR) which we have inculcated in our analysis of fault lines. This technique incorporates the transmission of a pulse down the cable, any change in the characteristics impedance will cause a part of the incident pulse to reflect back, this knowledge is helpful for locating discontinuities in a system.

scholarly journals Method for control the mechanical parameters of overhead power lines based on improved inclinometry

2019 ◽  
Vol 21 (3) ◽  
pp. 160-171 ◽  
Author(s):  
M. P. Goryachev ◽  
M. F. Sadykov ◽  
D. A. Yaroslavskiy
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Power Transmission ◽  
Power Lines ◽  
Mechanical Parameters ◽  
Power Transmission Lines ◽  
Mechanical Loads ◽  
Overhead Transmission Line ◽  
The Wire ◽  
Overhead Power Lines

Structural elements of overhead power transmission lines are experiencing both horizontal and vertical loads. Wires and cables are elements of the overhead power line, on which changes in mechanical loads are observed to a greater degree. This occurs due to the change in the tension force of the wire/cable depending on the temperature and the formation of icy-rime deposits on it, as well as fluctuations in wind gusts. The article describes the most common systems and methods for determining the mechanical loads on an overhead power transmission line. A method is proposed for calculating the mechanical loads on an overhead transmission line based on mathematical models of a flexible wire, rope and a model for determining ice deposits on wires, taking into account the rotation of the wire/cable around its axis. A comparison of the improved inclinometry method with the method developed earlier for the case of formation of ice deposits on the S-50 cable has been carried out. A comparison was made on the error in determining the tension of the S-50 ground-wire protection cable using the method developed to control the mechanical parameters of overhead power lines, which takes into account the wire/cable rotation around its axis and the method for determining icy-rime deposits developed earlier. The developed method allows determining the elongation of the wire/cable in the span with one anchor support, as well as the strength of its tension with greater accuracy. However, additional clarification is required due to the influence of the wind, the formation of icy-rime deposits of various shapes, as well as the structural limitations of the wire/cable rotation when attaching it to the support.

scholarly journals Time-Multiplexed Self-Powered Wireless Current Sensor for Power Transmission Lines

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1561
Author(s):  
Hao Chen ◽  
Zhongnan Qian ◽  
Chengyin Liu ◽  
Jiande Wu ◽  
Wuhua Li ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Transmission Line ◽  
Transmission Lines ◽  
Power Transmission ◽  
Current Measurement ◽  
Current Sensor ◽  
Power Transmission Line ◽  
Power Transmission Lines ◽  
Current Sensing ◽  
Self Powered

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.

Development on Environmental Geotechnology for Overhead Transmission Line Foundation Engineering in China

2012 ◽  
Vol 610-613 ◽  
pp. 2813-2818
Author(s):  
Xian Long Lu ◽  
Zeng Zhen Qian
Keyword(s):  
Transmission Line ◽  
Environmental Protection ◽  
Transmission Lines ◽  
Water Conservation ◽  
Design Method ◽  
Foundation Engineering ◽  
Foundation Construction ◽  
Overhead Transmission Line ◽  
Tower Foundation ◽  
Soil And Water

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.

A Novel IoT-Based Method for Real-Time Detection of Spontaneous Leaks in Pipelines, Gathering Systems, and Offshore Risers

2021 ◽  
Author(s):  
Matthew Grimes ◽  
Nico Van Rensburg ◽  
Stuart Mitchell
Keyword(s):  
Signal Processing ◽  
Transmission Lines ◽  
Negative Pressure ◽  
Pressure Wave ◽  
Long Distance ◽  
Non Invasive ◽  
Long Distance Transmission ◽  
Offshore Production ◽  
Offshore Risers ◽  
Oil Gas

Abstract This paper presents on a non-invasive, IoT-based method for rapidly determining the presence and location of spontaneous leaks in pressurized lines transporting any type of product (e.g., oil, gas, water, etc.). Specific applications include long-distance transmission lines, gathering networks at well sites, and offshore production risers. The methodology combines proven negative pressure wave (NPW) sensing with advanced signal processing to minimize false positives and accurately identify the presence of small spontaneous leaks within seconds of their occurrence. In the case of long-distance transmission pipelines, the location of the leak can be localized to within 20-50 feet. The solution was commercialized in 2020 and has undergone extensive testing to verify its capabilities. It is currently in use by several operators, both onshore and offshore.

scholarly journals Modeling Features of a Single Phase-to-Earth Fault in a Medium Voltage Overhead Transmission Line

2020 ◽  
Vol 4 (2) ◽  
pp. 127-138
Author(s):  
Ismael Saeed ◽  
Kamal Sheikhyounis
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Single Phase ◽  
Single Frequency ◽  
Mathematical Representation ◽  
Medium Voltage ◽  
Overhead Transmission Line ◽  
Earth Fault ◽  
Distributed Parameters ◽  
Selection Of

The modeling and calculation of a single phase-to-earth fault of 6 to 35 kV have specific features when compared with circuits with higher nominal voltages. In this paper, a mathematical analysis and modeling of a 3-phase overhead transmission line with distributed parameters consisting of several nominal T-shaped, 3-phase links with concentrated parameters replaced by 1 nominal T-shaped link were carried out. Further analysis showed that not accounting for the distributed nature of the line parameters did not cause significant errors in the assessment of the maximum overvoltage in the arc suppression in single phase-to-earth faults, and that sufficient accuracy insures the representation of the line by only 1 nominal T-shaped, 3-phase link. Such a modeling technique makes it impossible to identify the location of single-phase faults, which is the property of higher harmonic amplification of individual frequencies. Chain equivalent schemas with constant parameters are valid for a single frequency, thereby providing an opportunity to study the nature of the wave process by the discrete selection of parameters. Next in the mathematical representation, we consider the overhead transmission lines as lines with distributed parameters.

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