Safiev E.S., Abbasov V.I.
COMPLEX ANALYSIS OF TRANSITION SUPPORTS OF THE MAIN HIGH-VOLTAGE LINES *
Аннотация:
the article considers the analysis of methods for the complex diagnostics of the technical and corrosion state of the elements of the transitional supports of high-voltage lines. The existing problems that reduce the operational reliability and durability of the elements of transitional supports and the difficulties of diagnosing them are considered. The scope of work on the complex diagnostics of transitional supports has been formed
Ключевые слова:
overhead power lines, transitional supports, diagnostics, corrosion condition
УДК 537.312
Safiev E.S.
candidate of Technical Sciences, Associate Professor
of the Department "Electromechanics"
Azerbaijan State University of Oil and Industry
(Azerbaijan, Baku)
Abbasov V.I.
master of the Department "Electromechanics"
Azerbaijan State University of Oil and Industry
(Azerbaijan, Baku)
COMPLEX ANALYSIS OF TRANSITION SUPPORTS
OF THE MAIN HIGH-VOLTAGE LINES
Abstract: the article considers the analysis of methods for the complex diagnostics of the technical and corrosion state of the elements of the transitional supports of high-voltage lines. The existing problems that reduce the operational reliability and durability of the elements of transitional supports and the difficulties of diagnosing them are considered. The scope of work on the complex diagnostics of transitional supports has been formed.
Key words: overhead power lines, transitional supports, diagnostics, corrosion condition.
There are many overhead lines (OL) of power transmission, the main reasons for the failure of which are corrosion and aging of the supporting elements [1]. At the same time, if earlier the term “aging” referred mainly to non-metallic structures, then modern achievements in metal science indicate the existence of these processes in metal structures as well [2]. At the same time, the stronger the metal used in the structure, the earlier it may show signs of degradation of mechanical strength. It should be noted that if the process of corrosion destruction of materials of structures of overhead line supports is mainly determined by atmospheric and soil-climatic conditions along the overhead line route, then the aging process is more influenced by operating conditions, the design of overhead line supports and the voltage class.
The operation of the elements of overhead power transmission line supports at large crossings (span of more than 700 m) differs from the operation of other overhead line supports, primarily by the level of mechanical loads and the degree of influence of external hydrometeorological factors. The combination of wind, ice and temperature effects of the environment is manifested in a change in the frequency and amplitude of vibrations of the structural elements of transitional and anchor supports. Due to prolonged vibration, fatigue accumulates in the material of the overhead line elements. If for metal elements of overhead lines fatigue leads to an increase in the brittleness of the material, then for reinforced concrete structures it is expressed in a decrease in the strength of concrete.
The complex of transitional supports is a set of intermediate, anchor and end supports with a different scheme of their alternation on the overhead line route, depending on the specific conditions of the transition. The choice of one or another crossing scheme depends on a variety of operational conditions, both natural in nature and the infrastructural and technical features of a particular place for crossing obstacles. As a rule, crossings, especially through water barriers, are carried out according to individual projects, and therefore an examination of the technical and corrosion state of the elements of transitional supports also requires an individual approach.
In the general case, all known system and object diagnostic methods used to assess the state of overhead lines can be used to diagnose the state of transitional support elements. However, some design features of the execution of the transition (for example, a large height of supports, special foundations, often monolithic, a large depth of their immersion in the ground, the use of pipe supports on belts instead of ordinary angles, roller wire hangers, large mechanical loads on wires and cables, reinforced multi-chain garlands insulators, etc.), as well as atypical hydrological conditions, make appropriate adjustments to the methodology and technical equipment of diagnostics.
For example, the complex diagnostics of transitional supports through large water barriers, taking into account the need to study the problems identified by operating experience, may include:
- remote optical control (ultraviolet);
- thermal imaging inspection of wires of transitional supports;
- examination of the fatigue characteristics of steel-aluminum wires and lightning protection cables and the state of vibration protection;
- examination of the corrosion state of wires and lightning protection cables;
- survey of lightning resistance of transitions (resistance values of grounding devices of transitional supports, wire sag arrows, technical condition of linear insulation of overhead lines);
- inspection of the foundations of transitional and anchor supports;
- ultrasonic or electrochemical examination of metal structures of supports with measurement of the distribution of mechanical stresses and fatigue of metal structures along the height of transitional supports (fatigue, corrosion, mechanical stresses);
- examination of the state of illumination and light barriers of transitional supports;
- survey of the hydrology of the base of transitional and anchor supports;
- inspection and calculation of dimensions to the water surface at maximum temperatures.
Each of the above directions in the diagnosis of supports at crossings has its own instrumental and methodological bases, and the results of the survey deserve to be disclosed in a separate article.
Here you can only concentrate the problematic parts of each direction. For example, to assess the lightning resistance of transitions, knowledge is required on the selective lightning protection of local objects (transitional and end supports), to solve the problem of reliable and durable lighting of transitional supports, appropriate energy sources for light sources are needed, and to check the condition of large monolithic foundations of transitional supports (especially VL 500 kV), it is promising to use ultrasonic and seismoacoustic methods, as well as methods of standing waves. Of great importance is the study of the vibration characteristics of wires and lightning protection cables, as well as the reliability and durability of their suspensions on transitional supports, taking into account the methods used to protect them from vibration.
If we consider any large energy system as a whole, while proceeding from the task of ensuring uninterrupted and reliable power supply to consumers, then the sequence of solving problems that arise during the operation of electrical networks should inevitably come down to the following:
- finalization of regulatory and technical documentation regulating the operation of problematic elements of the electrical network of the power system;
- organization of monitoring of the technical condition of the elements of the electrical network, the defectiveness of which has already manifested itself in the problem being eliminated or similar to it;
- development of new materials, technologies and structures that ensure reliable and durable operation of problematic elements of the electrical network of the power system;
- carrying out scheduled work on the reconstruction, modernization and renewal of the electrical networks of the energy system.
- making proposals for adjusting the norms of technological design of power grid facilities for a given power system and prohibiting new construction, repair and reconstruction in it according to the old norms.
After the occurrence of a particular problem in electrical networks, these stages can be solved both sequentially and in parallel. However, without solving the first three stages and proceeding immediately to subsequent stages, the probability of recurrence of accidents in areas that have not yet been identified increases sharply, and the costs of finding optimal organizational and technical measures to prevent the occurrence of such problems in the future increase significantly. At the same time, diagnostics of problematic elements of the electrical network is necessary both at the initial stage of solving the problem, and at the stage of preventing such problems in the future.
Conclusion
For a more efficient continuation of diagnostic work and the use of modern innovative methods for monitoring the condition of overhead power lines, it is necessary to combine system and object diagnostics of overhead lines.
REFERENCES:
Номер журнала Вестник науки №11 (56) том 4
Ссылка для цитирования:
Safiev E.S., Abbasov V.I. COMPLEX ANALYSIS OF TRANSITION SUPPORTS OF THE MAIN HIGH-VOLTAGE LINES // Вестник науки №11 (56) том 4. С. 270 - 274. 2022 г. ISSN 2712-8849 // Электронный ресурс: https://www.вестник-науки.рф/article/6564 (дата обращения: 19.04.2024 г.)
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