scholarly journals Model of own harmonic conductor oscillations for tasks of monitoring the status of airline power transmission lines

Author(s):  
D. A. Yaroslavskiy ◽  
V. V. Nguyen ◽  
M. F. Sadykov ◽  
M. P. Goryachev ◽  
A. A. Naumov

The article substantiates the relevance of the inspection of overhead power lines by determining the mechanical loads of the conductors. The conductor sways under the action of external loads and variable internal mechanical loads. The conductor behaves in span like a pendulum. Using the inclinometric method, it is possible to determine the deviations of the conductor in space from its equilibrium position. Having restored the geometry of the conductor in the span of an overhead power line, mechanical loads can be determined. A model of the harmonic oscillations of the conductor in flight is derived to assess the mechanical loads of the conductor overhead power lines. This mathematical model is based on mathematical models of a flexible thread and a model of a physical pendulum. A conductor is a physical pendulum, where the conductor acts as the body, and in the role of the fixed axis of rotation, a straight line passing through the suspension points of the conductor. The developed model allows you to determine the arrow of its sag from the period of oscillations of the conductor in the span. The article considers algorithms for calculating the conductor sag arrows for two cases: the conductor suspension points are at the same height; conductor suspension points are at different heights. A theoretical calculation is given for a model of a span overhead power line with an estimate of the sensitivity of the developed model and its error in determining the sag of the conductor. Using the arrow of the conductor sag, you can restore its geometry, and hence the mechanical load of the conductor. Therefore, knowing the initial geometric parameters of the span of the overhead power line and the current period of the conductor’s oscillations, it is possible to examine its current state.

2020 ◽  
Vol 220 ◽  
pp. 01036
Author(s):  
Danil Yaroslavsky ◽  
Van Vu Nguyen ◽  
Marat Sadykov ◽  
Mikhail Goryachev ◽  
Dmitry Ivanov ◽  
...  

The article substantiates the relevance of the inspection of overhead power lines by determining the mechanical loads of the conductors. The conductor sways under the action of external loads and variable internal mechanical loads. The conductor behaves in span like a pendulum. A model of the harmonic oscillations of the conductor in flight is derived to assess the mechanical loads of the conductor overhead power lines. This mathematical model is based on mathematical models of a flexible thread and a model of a physical pendulum. A conductor is a physical pendulum, where the conductor acts as the body, and in the role of the fixed axis of rotation, a straight line passing through the suspension points of the conductor. The article briefly describes an algorithm for calculating the conductor sag for the case when the conductor suspension points are at the same height. The results obtained using the developed model for calculating the sag of the conductor by its period are compared with the available experimental data. Experimental equipment is described. The error of the method is estimated.


2019 ◽  
Vol 124 ◽  
pp. 05022
Author(s):  
M.F. Sadykov ◽  
D.A. Yaroslavsky ◽  
D.A. Ivanov ◽  
V.A. Tyurin ◽  
T.G. Galiyeva ◽  
...  

Mechanical deformations when a wire is stretched causes its rotation around its axis, which allows obtaining additional information about the wire behavior in an overhead transmission line and considering it no longer as a group of sections from one span but as a whole interconnected section with redistribution of mechanical loads between spans. To determine the tensile strength of wire by its torsion, a method for determining the mechanical parameters of an overhead transmission line was developed. It is based on the inclinometric method and the theory of force calculation of steel ropes. This technique takes into account the torsion, the angle of inclination and the wire temperature. The technique is implemented in the system for monitoring the status of overhead power lines. It takes into account the torsion angle of the wire and helps to prevent emergencies on the overhead power line by determining the tensile strength of the wire, checking for defects in wires of the overhead power line and defects in the suspension armature. The monitoring system includes control devices, data collection and data processing center, a dispatcher software package. Control devices are installed directly on the wire/ground wire of an overhead power line and are used to measure the angle of rotation, the angle of inclination and the wire temperature. The data collection and data processing station processes them according to the developed methodology in specialized software. The system for monitoring the status of overhead power lines based on the inclinometric method helps to prevent emergencies and reduce the economic costs of maintaining and restoring overhead power lines.


Author(s):  
Kostiantyn Kartalapov

The article considers the feasibility of using composite supports during the replacement of overhead power lines, analyzes the relevance of these technologies. The advantages of composite overhead power line towers for construction, modernization and restoration work over traditional wooden and metal towers are substantiated.


2020 ◽  
Vol 178 ◽  
pp. 01057
Author(s):  
Olga Ahmedova ◽  
Anatoliy Soshinov ◽  
Natalia Shevchenko

Devices of fault location are widespread in electrical grids. In overhead power lines of voltages of 10 kV and higher, such devices are based on measurements of parameters in emergency mode. These devices can be divided into two main groups: designed to determine fault location of short circuits and of ground short circuit. In both cases, when detecting fault location, analyzed are not only the current and voltage parameters at the accident time, but also the parameters of overhead power line. When analyzing equivalent circuits of power lines, approximate tabular values of direct and quadrature parameters are used. It was revealed, that the line parameters are significantly affected by external atmospheric factors: ambient temperature, soil moisture, wind strength and direction, ice formation, etc. To accurately determine the fault location, it is necessary to evaluate the influence of these factors on the linear parameters of the overhead line. The paper presents analysis of the influence of changes in atmospheric factors on parameters of overhead power line. A methodology for calculating the operation setpoints of the device for fault location in power line is given.


2020 ◽  
Vol 10 (10) ◽  
pp. 12-19
Author(s):  
Andrey V. GORSHKOV ◽  

It is proposed to ensure safety in carrying out work on a disconnected overhead power line by using a grounding conductor at the workplace having the impedance at which the induced voltage will be decreased down to permissible values. For reliably determining the necessary grounding conductor impedance, the results from multiple measurements of the induced voltage and current at the overhead power line point in which the work is carried out are used. Based on the results of measurements and solution of the inverse problems, empirical formulas for the functions of induced voltage and current in the considered place at which work on the overhead power line is carried out are determined. The necessary impedance of the grounding conductor at the workplace is determined using the obtained empirical formulas. As a result, a procedure has been developed using which it is possible to determine the grounding conductor impedance that ensures safety of work carried out at the considered place of the disconnected overhead power line whatever the combination of operating currents through the influencing overhead power lines.


2019 ◽  
Vol 124 ◽  
pp. 02010 ◽  
Author(s):  
V. A. Chernyshov ◽  
A. E. Semenov ◽  
V. E. Bolshev ◽  
R. P. Belikov ◽  
M. Jasinski ◽  
...  

The paper considers options for the implementation of the technical condition monitoring of the of power supply system elements, the assessment of overgrowing of the power line routes using an unmanned aerial vehicle. A method for emergency control of an unmanned aerial vehicle used to monitor the technical condition of 6-10 kV overhead power lines has been proposed. This method is used in case of loss of radio communication between the unmanned aerial vehicle and the ground control station. The method is based on the activation of the automatic piloting system allowing the unmanned aerial vehicle flight to continue to the pre-determined emergency landing area. The autopilot is carried out by means of a servo controller and sensitive sensors reacting to the intensity of the electromagnetic field of a 6-10 kV overhead power line.


2021 ◽  
Vol 3 ◽  
pp. 5-11
Author(s):  
Alexandr Shilin ◽  
Alexey Shilin ◽  
Sergey Dementyev ◽  
Nadezhda Kuznetsova

Ice buildup monitoring is essential to prevent wire breakage on overhead power lines. Conventional telemetry systems which are based on load cell sensors have some drawbacks as reflected in this paper. We suggest an innovative device for contactless ice buildup monitoring of overhead power line wires video recording the power line clearance. A specific algorithm for detecting the lowest point of wire sag has been provided. Also, we analyze a possibility of indirect contact sensor-free measurements of a wire temperature when the wire is being covered by icy deposits. A specific buildup type can be determined comparing a dew point and desublimation point as shown in this paper.


Author(s):  
M. P. Goryachev ◽  
M. F. Sadykov ◽  
D. A. Yaroslavskiy

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.


Electricity ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 316-329
Author(s):  
Arturo Popoli ◽  
Leonardo Sandrolini ◽  
Andrea Cristofolini

This paper presents a numerical study on the reduction in the voltage and current induced on a 13.5 km buried metallic pipeline by an overhead power line. The mitigation effectiveness of different configurations and cross-section shapes of screening conductors is computed by means of a methodology that combines a 2D Finite Element Analysis with circuital analysis. A 35.72% reduction of the maximum induced voltage is obtained when 4 cylindrical steel screening conductors with 8 mm radius are buried 0.25m below the soil surface, along the pipeline path. The maximum induced pipeline current is reduced by 26.98%. A parametric study is also performed, to assess the influence of the per-unit-length admittance to earth of the screening conductors on the mitigation efficacy. The results show that screening conductors may help in reducing the inductive coupling between overhead power lines and buried metallic pipelines, and that the assumption of perfectly insulated screening conductors leads to an underestimation of the produced mitigation effect.


2020 ◽  
Vol 17 ◽  
pp. 105-108
Author(s):  
Marko Kaasik ◽  
Sander Mirme

Abstract. The electric power that can be transmitted via high-voltage transmission lines is limited by the Joule heating of the conductors. In the case of coastal wind farms, the wind that produces power simultaneously contributes to the cooling of high-voltage overhead conductors. Ideally this would allow for increased power transmission or decreased dimensions and cost of the conductor wires. In this study we investigate how well the wind speed in coastal wind farms is correlated with wind along a 75 km long 330 kW power line towards inland. It is found that correlations between wind speed in coastal wind farms at turbine height and conductor-level (10 m) are remarkably lower (R=0.39–0.64) than between wind farms at distances up to 100 km from each other (R=0.76–0.97). Dense mixed forest surrounding the power line reduces both local wind speed and the correlations with coastal higher-level wind, thus making the cooling effect less reliable.


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