This study conducted a comprehensive assessment of the response of wetland ecosystems in temperate and polar latitudes, located on different continents, to extreme weather events. These events included temperature anomalies (unusually high/low temperatures) and precipitation anomalies (droughts/intense precipitation). The analysis of the response net ecosystem exchange (NEE) of CO2 and latent heat (LE) fluxes to extreme temperature and precipitation events used ERA5 reanalysis data [Smith, 2011] and observations of CO2 and LE fluxes from the global FLUXNET database [https://fluxnet.org/data/]. Fifteen greenhouse gas flux monitoring stations were selected for the study, representing the longest and most continuous time series of observations. These stations are located on different continents, with eight stations in temperate latitudes and seven in polar regions. It should be noted that this study focused exclusively on the warm season. The beginning and end of the warm season were defined as the sustained crossing of the daily mean air temperature above 0°C for at least seven consecutive days. For each station, daily anomalies of CO2 and LE fluxes were calculated as the deviation from the long-term mean values for the corresponding day of the year. Extremely high/low values of flux anomalies were identified as exceeding one standard deviation from the overall time series for each calendar month individually. To identify periods with extreme air temperature values, ERA5 reanalysis data on two-meter air temperature every 3 hours with a spatial resolution of 0.25°×0.25° from 1991 to 2021 were used. To estimate extreme precipitation amounts, data from half-hourly station observations were used. Daily means were calculated from these data in a first step. Thresholds for defining extremely hot/cold periods were calculated as daily mean air temperature exceeding the 95th percentile (for anomalously hot periods) or not exceeding the 5th percentile (for anomalously cold periods) of a normal distribution with mean and standard deviation. The distribution was constructed for a specific month of the year and then averaged over the entire period considered. Two approaches were used to determine the extreme precipitation threshold. In the first approach, extreme precipitation days were defined as days with daily precipitation exceeding the 95th percentile of the probability density function (the Weibull distribution was used for precipitation). The second approach was based on the assessment of the Antecedent Precipitation Index (API), which determines the cumulative effect of precipitation on CO2 fluxes. For the quantitative assessment of the relationship between temperature and precipitation extremes and flux anomalies, the percentages of days on which both the NEE/LE anomaly exceeded the standard deviation and the temperature/precipitation exceeded the 95th percentile for the upper threshold or the temperature did not reach the 5th percentile for the lower threshold were calculated. The percentage was calculated based on the total number of days when one of the characteristics (air temperature, daily sum of precipitation) exceeded the threshold. The analysis showed that temperate and polar wetland ecosystems can respond differently to temperature and precipitation anomalies. These differences can be attributed to the geographic location of the ecosystem, regional climatic conditions, plant species composition, and the intensity of temperature and precipitation extremes. During the warm half of the year, periods of extremely high temperatures in temperate latitudes were associated with a positive CO2 flux anomaly, corresponding to an increased emission of CO2 into the atmosphere. In contrast, polar latitudes showed an opposite response - an increase in CO2 uptake by wetland ecosystems under anomalously high temperatures. This opposite response of CO2 fluxes may be related to the different soil moisture regimes in polar wetland ecosystems and the different plant species composition. Extremely high temperatures were accompanied by positive LE anomalies due to the intensification of evaporation processes with rising temperatures, a trend observed in all wetland ecosystems analyzed. The immediate response of wetland ecosystems to intense precipitation (above the 95th percentile) was manifested as an increase in CO2 flux to the atmosphere at almost all stations analyzed. This observed response could be related to the "Birch effect" [Birch, 1964], which is characterized by an intensification of soil respiration due to a sudden increase in soil moisture and, consequently, an increase in the rate of decomposition and mineralization of organic matter during heavy precipitation and rising groundwater levels. LE flux decreases during intense precipitation, indicating suppression of evaporation due to high humidity and reduced incoming solar radiation. The cumulative effect (API index) of extremely high precipitation is characterized by a predominance of extremely positive CO2 flux anomalies over negative ones in wetland ecosystems at both temperate and polar latitudes. It should also be noted that the percentage of days with increased CO2 uptake during the two weeks following intense precipitation is significantly higher than for the immediate response (10-25% of days in temperate latitudes and 5-20% of days in polar latitudes). The increase in CO2 uptake after heavy precipitation may be related to enhanced photosynthetic rates of the vegetation cover under sunny weather and optimal soil moisture conditions. A prolonged absence of precipitation, represented by extremely low API values, is accompanied by negative CO2 flux anomalies (enhanced uptake) at most of the studied wetland ecosystem stations, indicating a high adaptive potential of the studied wetland ecosystems to short-term (less than 14 days) dry periods. On the other hand, enhanced CO2 uptake could be facilitated by clear weather conditions, which prevail during dry periods and are accompanied by an increase in direct solar radiation and corresponding acceleration of photosynthetic processes. It is noteworthy that flux anomalies often did not coincide with temperature or precipitation extremes, indicating that the functioning of wetland ecosystems is strongly influenced by multiple abiotic and biotic factors, which vary among different plant communities.

The spatial variability of CO2 and CH4 fluxes at two experimental carbon supersites with non-uniform vegetation and complex topography located in the Krasnodar krai and the Chechen Republic is estimated based on the results of field measurements and model experiments. The results show a significant spatial heterogeneity of the wind speed, turbulent coefficient, and vertical CO2 and CH4 fluxes. It is influenced by complex topography and mosaic vegetation, as well as by an uneven distribution of CO2 and CH4 sources and sinks in vegetation and soil cover. It has been shown that on the summer days of 2022 in similar weather conditions, both experimental sites served as sinks of greenhouse gases: the Roshni-Chu forest area in the Chechen Republic absorbed 5.18 g CO2e/(m2 hour), while the Black Sea coastal area in the Krasnodar krai absorbed only 2.95 g CO2e/(m2 hour).

Modern climate change, accompanied by rapidly increasing global air temperature, changing precipitation patterns, frequency and severity of extreme weather events, may have a significant impact on the functioning, growth, and development of forest ecosystems. The aim of the study was to assess the effects of extreme weather events (significant positive and negative anomalies in air temperature and precipitation) on the carbon dioxide (CO2) fluxes in boreal and temperate forest ecosystems in the Northern Hemisphere. 26 greenhouse gas (GHG) flux monitoring stations of the global FLUXNET network with the most continuous observations were selected for the analysis of CO2 fluxes. The stations are located in forest ecosystems of different biome types according to the IGBP classification. Meteorological conditions were analyzed using observations from meteorological stations and ERA5 reanalysis data. The results showed that the response of CO2 fluxes to temperature and precipitation anomalies varies depending mainly on the type of forest ecosystem, its geographical location and regional climatic conditions. Extremely high air temperature in any season leads to increased CO2 emissions to the atmosphere in all forest types studied, with the most pronounced response in coniferous forests. Negative air temperature anomalies in the warm season could have the opposite effect, either increasing or decreasing the CO2 uptake by forest ecosystems, depending on the forest ecosystem type. No significant response of CO2 fluxes to extremely low temperatures in the cold season was found. During periods of heavy precipitation, the emission of CO2 to the atmosphere dominated in all forest ecosystems under study. At the same time, after a large amount of precipitation during the warm season, a cumulative effect of available soil moisture in the plant root zone on CO2 fluxes was revealed. As a result the CO2 uptake by vegetation increases due to the growing rate of plant photosynthesis under sufficient soil moisture conditions.

Актуальность работы. Основные используемые на данный момент методы измерения потоков парниковых газов в полевых условиях, такие как метод экспозиционных камер и метод турбулентных пульсаций, имеют ряд методических ограничений. Это затрудняет их широкое использование на местности с неоднородной подстилающей поверхностью, особенно в горных регионах. Поэтому весьма актуальной является задача разработки новой рабочей методики для оценки потоков парниковых газов, применимой над поверхностями со сложным рельефом и неоднородной растительностью, основанной на методах дистанционного зондирования и математическом моделировании. Цель работы заключается в формулировке методики оценки потоков парниковых газов на основе данных измерений концентрации парниковых газов на двух уровнях над поверхностью и применения трехмерной гидродинамической модели турбулентного переноса парниковых газов. Также цель работы включает исследование репрезентативности предложенной методики. Методы исследования. С помощью разработанной ранее гидродинамической модели, модифицированной для учета влияния рельефа, оценивается коэффициент турбулентного обмена для парниковых газов и поле скорости ветра. При наличии измеренных полей концентрации парникового газа на двух уровнях над поверхностью (например, с помощью БПЛА) и модельных данных для коэффициента турбулентности и скорости ветра поток парникового газа оценивается по предложенной в работе приближенной формуле, включающей в себя аппроксимацию вертикального турбулентного и адвективного потоков. Приближенная формула может также использоваться как начальное приближение при решении обратной задачи оценки потока парникового газа, также сформулированной в работе. Результаты работы. На основе ряда численных экспериментов, проведенных для лесного участка карбонового полигона в Рошни-Чу (Чеченская республика) и предложенной в работе аналитической оценки получено распределение потоков CO2 над кронами деревьев, проведено их сравнение с теоретически ожидаемым распределением, а также найдены оптимальные уровни над поверхностью для проведения измерений концентрации парниковых газов.

Основные используемые на данный момент методы измерения потоков парниковых газов в полевых условиях, такие как метод экспозиционных камер и метод турбулентных пульсаций, имеют ряд методических ограничений. Это затрудняет их широкое использование на местности с неоднородной подстилающей поверхностью, особенно в горных регионах. Поэтому весьма актуальной является задача разработки новой рабочей методики для оценки потоков парниковых газов, применимой над поверхностями со сложным рельефом и неоднородной растительностью, основанной на методах дистанционного зондирования и математическом моделировании. Цель работызаключается в формулировке методики оценки потоков парниковых газов на основе данных измерений концентрации парниковых газов на двух уровнях над поверхностью и применения трехмерной гидродинамической модели турбулентного переноса парниковых газов. Также цель работы включает исследование репрезентативности предложенной методики. Методы исследования. С помощью разработанной ранее гидродинамической модели, модифицированной для учета влияния рельефа, оценивается коэффициент турбулентного обмена для парниковых газов и поле скорости ветра. При наличии измеренных полей концентрации парникового газа на двух уровнях над поверхностью (например, с помощью БПЛА) и модельных данных для коэффициента турбулентности и скорости ветра поток парникового газа оценивается по предложенной в работе приближенной формуле, включающей в себя аппроксимацию вертикального турбулентного и адвективного потоков. Приближенная формула может также использоваться как начальное приближение при решении обратной задачи оценки потока парникового газа, также сформулированной в работе. Результаты работы. На основе ряда численных экспериментов, проведенных для лесного участка карбонового полигона в Рошни-Чу (Чеченская республика) и предложенной в работе аналитической оценки получено распределение потоков CO2над кронами деревьев, проведено их сравнение с теоретически ожидаемым распределением, а также найдены оптимальные уровни над поверхностью для проведения измерений концентрации парниковых газов. The main methods currently used to measure greenhouse gas fluxes in the field, such as the chamber method and the eddy covariance method, have a number of methodological limitations. This makes it difficult to apply these methods widely in terrain with inhomogeneous underlying surface, especially in mountainous regions. Therefore, the task of developing a new working methodology for estimating greenhouse gas fluxes applicable over surfaces with complex topography and inhomogeneous vegetation based on remote sensing methods and mathematical modeling is very urgent. The aim of the paper is to formulate a methodology for retrieving greenhouse gas fluxes based on the data of greenhouse gas concentration measurements at two levels above the surface and the application of a three-dimensional hydrodynamic model of turbulent greenhouse gas transport. aim of the paper also includes the study of the representativeness of the proposed methodology. Research Methods. Using a previously developed hydrodynamic model modified to account for the effect of topography, the turbulent exchange coefficient for greenhouse gases (GHG) and the wind speed field are estimated. With measured GHG concentration fields at two levels above the surface (e.g., using a UAV) and model data for the turbulence coefficient and wind speed, the GHG flux is estimated using the rough formula proposed in the paper, which includes an approximation of the vertical turbulent and advective fluxes. The proposed formula can also be used as a first approximation for solving inverse problem of GHG flux retrieval, which is also given in the paper. Results.Based on a series of numerical experiments that were carried out for the forest area of the Carbon Experimental Site in Roshni-Chu (Chechen Republic) and the analytical evaluation proposed in the paper, the distribution of CO2fluxes over the tree canopy was obtained. They compared with the theoretically expected distribution, and the optimal levels above the surface for measuring greenhouse gas concentrations were found.

THE PURPOSE. To investigate the problem of evaluating the energy-efficient operation of low-voltage switching devices installed in electrical complexes, to analyze the current state of the Russian market of electrical devices and to develop an algorithm and models of the main technical characteristics of circuit breakers of electromagnetic starters and contactors of various manufacturers.METHODS. In solving this problem, the ratio of the nominal current of the device and the resistance of contacts and contact connections of devices of some manufacturing plants is investigated. The analysis of experimental data showed what kind of functional dependences of contact resistances on the rated current have.RESULTS. Approximating functions have been developed based on the results of experimental studies of the value of contact resistances from the main nominal parameters of automatic machines, electromagnetic starters and contactors of some manufacturers.CONCLUSION. The article develops an algorithm and models for evaluating the energy efficiency of operation of low-voltage electrical devices, allowing to specify the amount of power (electricity) losses in equipment and recommended to increase the reliability of calculating electricity losses in low-voltage networks of electrical complexes.

THE PURPOSE. To develop a stand for the study of the operability and quality of functioning of electrical complexes and electric drive systems with frequency regulators that have undergone major repairs.METHODS. When solving this problem, the method of direct evaluation of the mechanical characteristics of the system Source-Frequency ConverterMotor-Load was used, methods of direct evaluation of input parameters with subsequent calculation of indicators, methods of increasing algorithmic redundancy, mathematical methods of checks, logical control methods and complex control methods (the method of control tests, the method of control programs) were used. RESULTS. The analysis of test methods of frequency regulators was carried out, the necessary equipment was selected, stand control algorithms were determined, design documentation was developed, a stand was made to study the operability and quality of functioning of electrical complexes and electric drive systems with frequency regulators, the software of its control system was debugged, frequency converters were tested according to the developed methodology in accordance with GOST requirements.CONCLUSION. One of the most effective ways to determine the state of the frequency controller before sending it for installation is to check on a test bench to determine the degree of operability of the control and protection system, as well as the power part. The developed stand makes it possible to solve a wide range of tasks for the study of the operability and quality of functioning of electrical complexes and electric drive systems with frequency regulators that have undergone major repairs.

This article describes the features of voltage regulation in electrical networks of 35, 110, 220 kV. The structural diagram of the 35/10/0.4 kV network is presented. The paper also describes the adaptive automatic voltage regulation system which allows regulating the voltage taking into account the actual voltage values at the consumers’ inputs. The structural diagram of the adaptive automatic voltage regulation system in the 0.4 kV electrical network using a boost transformer as an additional means of voltage regulation is given. The system is based on voltage sensors installed in different parts of an eletcrical network sending information on voltage values to to the processing unit which generates a signal for voltage regulating supplied to the executive device and the working body whuch, in turn, change the on-load tap-changer position of a transformer. The paper justifies the need for the enhancement of the adaptive automatic voltage regulation system for different voltage classes wich allows controlling a voltage change at different power supply system levels and regulating voltage level in accordance with this change. For this problem the multi-level adaptive automatic voltage regulation systemis proposed. The system allows regulating the voltage not only in the 0.4 kV network but also in networks of higher voltage classes. The proposed system can be integrated into the structure of intelligent electrical networks.

Automatic sectionalizing and redundancy of power transmission lines is one of the conditions for network intellectualization and can significantly reduce the power supply interruption time for rural consumers. However, both sectionalizing and redundancy of power transmission lines in 0.4 kV electric networks are used extremely limitedly since there are no sufficiently effective methods and technical means for their implementation. This article presents a method to automatically deactivate the automatic load transfer switch when restoring the normal network operation mode. The paper considers the implementation of the method on the example of damage occurring in the network where power is supplied to consumers from two power sources using an automatic load transfer switch and two sectionalizing units. A device is developed which allows implementing the developed method of automatic load transfer switch deactivation. The device consists of sectionalizing unit, automatic load transfer switch, voltage presence sensor, power direction sensor, memory element, repeater element, element AND and 3 elements NOT. The work of the device is described. The proposed method for automatically disconnecting the automatic load transfer switch in order to return the consumers’ power supply circuit to its initial state solves the problem of eliminating unreasonable power supply interruptions for consumers.

In the modern oil industry, the vast majority of oil production units are represented by sucker rod pumping units, driven mainly by asynchronous electric motors without using any monitoring, control and regulation means. Studies carried out on such installations show their low energy efficiency and reliability. Therefore, the issue of developing complex electric drives of a new generation based on the use of synchronous valve electric motors is relevant allowing to significantly increase the energy efficiency and reliability of both individual installations and to ensure the creation of "smart" oil field control systems. The paper discusses new technical solutions of the experimental stand which makes it possible to study the energy characteristics of electric drives based on asynchronous and synchronous valve electric motors, as well as allowing to create conditions as close as possible to real field conditions with imitation of the operation of an oil pumping unit of a sucker rod pumping unit. In modern test equipment systems, devices are often used to create a mechanical load on the shaft of the electric motor under study. The system proposed and implemented as such a device is "a frequency converter - load asynchronous electric motor", which has been tested on a stand and has proven to be the best in comparison with traditional circuits using DC motors. But using of a load asynchronous electric motor as part of the test stand has revealed a number of disadvantages: overheating of the electric motor operating in the opposing mode, low accuracy of creating the load torque and the speed of the system's response. The problem of overheating of the load electric motor has been solved by transferring the frequency converter to the direct torque control mode, while a significant decrease in the motor current and stabilization of the temperature regime have been detected. The low accuracy and response speed of the system have been increased by introducing feedback and a PID controller into the stand control system.

: This article deals with the issues of an objective assessment of the technical condition of asynchronous motors with voltage up to 1000 V. A stand is proposed for post-repair tests. Test stand allows you to conduct induction motor tests to form an objective conclusion about the technical condition and quality of the repair carried out automatically.

Object. The object of research is the modernization of the drives of oil pumping units through the use of synchronous motors and adaptive control systems. Field of application: electrical equipment for oil pumping units.The purpose of the work is to identify inventions in the field of electric drives based on Russian highly efficient synchronous motors for oil pumping machines, to determine the advantages and disadvantages of modern developments in this field.Methods. This analysis will reveal the strengths of the drive being developed and most competitively present them. An important point is, and checking the possibility of patenting in this area, i.e. check for patent purity.Results. As a result of the study, the most significant inventions (based on the patent analysis of the Russian Federation) were identified in the field of sucker rod pump control stations, dynamometry, and wattmetry, which are presented in the work, they provide a brief overview, provide basic information and novelty.Conclusion. A literature review showed that the issues of control stations for sucker rod pumps, dynamometry, wattmetry, and the development of synchronous electric motors are rather deeply covered, on the other hand, the literature does not sufficiently reflect the problems of frequency regulation of synchronous motors, as well as the capabilities of intelligent control stations that would allow increase the level of oil production, optimize the technological process, significantly reduce the influence of the “human” factor improve production safetyThus, the need to create a competitive electric drive for oil pumping machines is the use of “smart” control systems that will regulate the operation of the well due to adaptive (based on automatic analysis of dynamograms and wattmetergrams) private regulation.

В первых четырех главах рассмотрены различные аспекты проектирования систем освещения. Предмет изучения охватывает помимо прочего, проектирование систем аварийного освещения для промышленных, коммерческих и бытовых помещений, а также конструкцию ламп и осветительной арматуры. Последний объект называют светильниками. Пятая глава посвящена вопросам энергосбережения и техникоэкономическому расчету установок освещения. Рекомендовано учебно-методическим советом института электроэнергетики и электроники ФГБОУ ВО «Казанский государственный энергетический университет» для студентов очной формы обучения направления подготовки 13.03.02. Электроэнергетика и электротехника. Авторы пособия являются сотрудниками кафедры «Электроснабжение промышленных предприятий» ФГБОУ ВО «КГЭУ». Гибадуллин Р.Р. доцент кафедры, к.т.н. и Денисова Н.В. доцент кафедры, к.ф.-м.н., доцент непосредственно преподают данную дисциплину. Ившин И.В. заведующий кафедрой, д.т.н., профессор руководит ВКР с элементами проектирования освещения.

The article describes a Sensorless method for determining the position of the movable element electrical machines reciprocating action. The method is implemented on the basis of the data voltages of the windings and the results of measurements of parameters of electrical machines reciprocating action.

They performed the theoretical studies in the software complex ANSYS to determine the information frequencies of the natural oscillations of gas engine parts associated with certain types of defects. A new method of non-contact vibration control (MNCVC) was developed for the state of complex details based on the use of informative natural vibration frequencies associated with certain types of defects. The developed and created a new instrumentation-measuring and software complex to implement a new MNCVC of complex-shaped parts using laser vibrometry methods. Experimental studies of the natural oscillation parameters of the gas engine parts have been carried out and the working capacity of the new MNCVC state for the power plant parts was confirmed.

The paper describes new engineering solutions when developing a test bench for studying experimental models of reciprocating electrical machines, as well as the hardware-software control system. A crank mechanism was used when developing the bench to create hydraulically driven reciprocating motion. The designed hardware-software system allows for controlling the bench and the test subject due to a large number of inputs and outputs of various applications. The sensors integrated into the bench allow for constructing the complete picture of the test and receiving a sufficient amount of high-precision data. The high flexibility of the bench and the test subject control algorithm allows for conducting a wide range of various tests of electrical products.

The paper describes new engineering solutions at developing a test bench for studying experimental models of reciprocating electrical machines, as well as the hardware-software control system. A crank mechanism was used when developing the bench to create hydraulically driven reciprocating motion. The designed hardware-software system allows for controlling the bench and the test subject due to a large number of inputs and outputs of various applications. The sensors integrated into the bench enable a complete test picture and sufficient amount of high-precision data. A high flexibility of the bench and the test subject control algorithm allows for conducting a wide range of various tests of electrical products.