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. It is a very challenging task to correctly use weather data to calculate the active power loss due to corona in overhead power lines. One of the significant reasons for this was the problem of accuracy of determining weather conditions and the use of the forecast for calculating extended overhead lines. In the USSR (Union of Soviet Socialist Republics), based on field tests and experimental data, recommendations were developed for accounting for losses of electric energy due to corona and interference in overhead lines, the average values of which were given in the relevant instruction for the regulation and justification of the norm of electricity consumption for its transmission over electric networks. According to this regulatory document, the specific cost of active power due to corona in overhead lines, averaged by design, was determined depending on weather conditions, which were divided into four groups. In this paper, the effect of active power losses on corona is estimated using various factors on the example of high-voltage overhead lines in the main electrical networks of the Republic of Belarus of various rated voltages. Dependences of active power losses due to corona have been constructed and modeled, taking into account different climatic and weather conditions observed in the country. The determination of metrological parameters was based on the analysis of weather data and patterns of types of weather conditions. In order to improve the accuracy of calculating the specific losses of active power due to corona, all possible weather conditions were considered, as well as their combinations. Afterwards, the data on weather conditions were processed and their types were reduced to one of the four existing types of weather. A method for determining electric power losses due to corona in overhead lines based on the average relative air density and geometric parameters of the predominant section of overhead lines has been proposed and presented. It is shown that the usage of exclusively rated voltage can cause errors in determining both the specific and actual values of active power losses for corona.

THE PURPOSE. paper show digital system for monitoring of single-phase earth faults on overhead power lines of 10 kV voltage in distribution power grids with an isolated neutral mode. METHODS. Digital system analyze frequency and amplitude of higher harmonics of voltage and current. The digital monitoring system includes the features of technical solutions for the selection of higher harmonics. RESULTS. Simultaneously, the paper shows the layout solutions for connecting a monitoring system to the control circuits on the10 kV side of 110/10 kV voltage substation. Software implemented for the far monitoring of the power grids and can detect of various types of single-phase earth faults. CONCLUSION. Software base on the mathematical models, as well as taking into account the results of a series of full-scale experiments of modeling various types of single-phase earth faults in the distribution power grids. The main functionalities the developed software presented for the description of solutions. Paper show further directions of research of the diagnostics and monitoring of single-phase earth faults in distribution power grids with overhead power lines based on the analysis of higher harmonic components.

The problem of searching for damage on overhead lines due to a lightning discharge is relevant for consumers of electricity and its suppliers. A direct lightning strike into power line elements leads to the destruction of insulators, breakage of wires and cables, and a consumer disconnection. The main task of the maintenance staff is to search for damage that occurs after a lightning discharge. Usually, special devices are used, they are installed in substations and based on the wave method, the visual method is also used. The paper proposes a model for detecting likely damage to power transmission line elements by creating a detailed database on the region's power transmission line and combining this database with a real-time archive of lightning discharges. The model in accordance with the proposed algorithm will make it possible to compile a list of supports likely to be affected by a lightning discharge, to identify the affiliation of these supports to specific power lines, and to notify the maintenance personnel of these power lines about the coordinates and supports of the power lines, where damage is possible. The model has a low cost and operating cost, can be easily deployed in any power system, but requires sufficient accuracy to detect lightning discharges and determine their coordinates. The solution to the problem of detection accuracy comes down to installing in the region a certain number of lightning direction finders of a particular system. The paper considers these issues on the example of the power system of the Murmansk region and lightning direction finders of the Blitzortung system.

In the standard for contact wires made from copper and its alloys, the values of long-term permissible temperatures have significantly decreased. This requires recalculation of previously valid values of long-term permissible currents. Authors considered revised method for calculating the long-term permissible currents, based on a more rigorous consideration of the laws of heat transfer and experimental studies of the conditions of heating and cooling of shaped (contact) and stranded wires. Technique is based on heat balance conditions, using which the sources of greatest inaccuracies become such quantities as cooled surface area, influence of wind direction, meteorological conditions, laws of change in heat transfer coefficient, effect on additional heating of solar radiation. Deviations when these indicators are taken into account by existing methods can cause errors of 40 % or more. Formulas for calculating the actual outer surface of stranded and shaped wires are given. The inadmissibility of calculating the surface area of the wires by their reference diameter is noted. Updated law of the change in heat transfer coefficient for stranded and shaped wires, as well as the degree of its dependence on wind speed and cooled surface, is given based on a summary of extensive domestic and foreign research. It is shown that with the longitudinal direction of the wind, the reduction of this coefficient occurs to a lesser extent than has been assumed so far. Authors propose method for taking into account an increase in the heat transfer coefficient under meteorological conditions characteristic of ice formation. The heat transfer coefficient of shaped and stranded wires in no case can not be taken as for round pipes with smooth surface. Existing method of accounting for solar radiation, which influences the additional heating of wires, leads to an unjustified and repeated exaggeration of this effect, since previously only the radiation incident on the wire was taken into account in the calculations. According to the laws of heat transfer, the temperature of the irradiated body does not depend on the incident, but on the resulting radiation, defined as the difference between the radiations incident on the body and emitted by it in accordance with its temperature. A formula for accounting for such heat transfer is proposed. The above methodology and calculation formulas allow performing reasonable calculations to determine the long-term permissible currents of individual stranded and shaped wires, as well as the contact network as a whole.

In this article, we present the methods used to date, the choice of the cross-sections of the wires of overhead transmission lines, taking into account not only the losses from the load currents, but also the corona losses and linear insulation of overhead transmission lines. The method of economic optimization of electrical loads and current density in operating air lines is considered, where the target functions are the specific discounted costs for transmission of 1 kW. h of electric power.

The paper analyzes the impact of environmental factors of physical and chemical nature on the stability of the development of three species of woody plants: common lilac, Siberian apple tree, birch tree. Determining the value of the fluctuating asymmetry index (FA) over the width of two halves of leaves was performed on plants growing in the suburban green area (control), in the suburban green area under high-voltage power lines of 220 kV (physical factor, experiment 1), as well as in the city of Krasnoyarsk in terms of air pollution by exhaust gases of cars (chemical factor, experiment 2). The values of the FA index of common lilac and Siberian apple tree, defined for the control variants, were 0.024 and 0.028, and calculated for experiments 1 and 2 were respectively equal to 0.032 and 0.039; 0.029 and 0.030. It is established that the response of common lilac and Siberian apple trees to the physical environmental factor - electromagnetic radiation of industrial frequency - which is expressed in the appearance of leaf asymmetry is stronger in comparison with the reaction to the chemical factor - exhaust gases of cars. It is shown that the value of the FA index of Siberian apple tree and common lilac can be a sensitive indicator when monitoring the anthropogenic load on the environment in the form of an alternating electromagnetic field of industrial frequency. The FA index of the birch tree, measured on the basis of the width of the right and left halves of the leaf, is less sensitive than in the case of the common lilac and the Siberian apple tree.

In the article the analysis of the proportion of lightning strikes in the towers and the upper phase wire of the span of overhead transmission lines without ground wire, made in accordance with different applicable in the Russian Federation, regulatory documents of lightning. Built zone protection of the towers on transmission lines lines without ground wire depending on the span length and the height of the towers. Seem significant differences of the results of assessments by different techniques. The results of the builds were revealed the need to refine existing methods to determine the fraction of lightning strikes in the towers and phase wirles.

Purpose. The synthesis of the active shielding systems by technogenic magnetic field generated by the different types of high voltage power lines in a given region of space using various cables of controlled magnetic field sources. Methodology. The initial parameters for the synthesis of active shielding system parameters are the location of the high voltage power lines with respect to the protected transmission line space, geometry and number of cables, operating currents, as well as the size of the protected space and normative value magnetic field induction, which should be achieved as a result of shielding. The objective of the synthesis of the active shielding system is to determine their number, configuration, spatial arrangement, wiring diagrams and compensation cables currents, setting algorithm of the control systems as well as the resulting value of the induction magnetic field at the points of the protected space. Synthesis of active shielding system is reduced to the problem of multiobjective nonlinear programming with constraints in which calculation of the objective functions and constraints are carried out on the basis of Biot – Savart – Laplace law. The problem is solved by a stochastic multi-agent optimization of multiswarm of particles which can significantly reduce the time to solve it. Results. Active screening system synthesis results for the various types of transmission lines and with different amounts of controlled cables is given. The possibility of a significant reduction in the level of induction of the magnetic field source within a given region of space. Originality. For the first time carried out the synthesis of the active shielding systems, by magnetic field generated by the different types of high voltage power lines within a given region of space controlled by a magnetic field sources with different amounts of controlled cables. Practical value, Practical recommendations on reasonable choice of the number and spatial arrangement of compensating cables of active shielding systems for different types of high voltage power lines in order to ensure the effectiveness of a given shielding of the magnetic field high voltage power lines.

This report presents information on the eastern imperial eagle nesting on electricity pylons in the Republic of Tatarstan (area of 67836.2 km2) on the eastern part of East-European (Russian) Plain, where the habitat of this species, marked in GIS (ArcView 3.2a), is 49 thousand km2. During the research in 2011–2015 5 nests were found on steel electricity pylons, which sustains 3.25% from the whole amount of nesting areas (n=154). Rather local disposition of all found cases of nests on electricity pylons in Eastern Zakamye (High Zavolzhye) limited by one landscape subzone – typical and southern forest-steppe, and in only two landscape regions with adjacent borders – indicates some general conditions which caused the adaptation. Distance between nests on power lines in the Republic of Tatarstan ranged from 21.5 to 49.9 km, averaging 29.5±13.64 km (n=5). As this territory lacks interspecific competition, the main reason of nesting on electricity pylons is probably the reduction of distance to forage resources in conditions of intraspecific competition in the densest nesting group. Adaptive capabilities of the Eastern Imperial Eagle are connected with their ability to occupy nests of other birds, high tolerance to human influence, and with the high density of the power lines and low density of long-boled forests. It’s reported that the imperial eagles’ adaptation to living in environment with dense power line network continues, which expresses in increase of the nesting on electricity pylons.