Relevance of the study lies in the development of intelligent power supply systems (IPS), which implies the improvement of existing, implementation and improvement of modern protection, diagnostic systems, monitoring of high-voltage electrical equipment (HVE) elements.

The purpose. To consider modern state, as well as the ways of development and possibilities of integration of protection and diagnostic systems of cable-overhead lines (COL) of IPS.

Methods. For solving the problem, a comparative analysis of the reasons that lead to the operation the protection systems of the COL of IPS, their shortcomings and possible ways of their improvement were carried out. The current state of protection, diagnostics, monitoring of COL of IPS and the ways of their development were analyzed. In particular, promising methods for diagnosing insulation, coupling joints of cable lines (CL) according to the characteristics of partial discharges (PD), overhead lines (OL) elements according to the data of thermal imaging inspection were considered. RESULTS. The article provides an overview of existing protection and diagnostic systems for COL of IPS of high and medium voltage classes. The article is devoted to current issues protection development of ISE of distributed generation, which include renewable energy source (RES) generators, in order to prevent overvoltage and ensure uninterrupted power supply to consumers in distributed generation systems. The article considers current issues of development of modern methods of COL diagnostics up to the level of monitoring systems, including using thermal imaging survey methods, dielectric impedance spectroscopy (DIS), and the PD method.

Conclusion. Development of ISE will be one of the main task for a long time. The most advanced ISE protections will be adaptive protections using artificial neural networks (ANN) in which be integrate the most modern mathematical algorithms and diagnostic methods, primarily smart grids technologies, microgrids technology, independent component method (ICM), PD methods, thermal imaging survey, electrical impedance spectroscopy (DIS), and dielectric spectroscopy (DS).

The purpose. Introduction into the bridge movement drive control system of a bridge support movement synchronization unit, developed in stages on the basis of fuzzy logic to eliminate bridge tilt arising as a result of the movement of a flexible suspension load along the bridge by a trolley.

Methods. The objectives set in the study were achieved through the use of mathematical modeling in the Matlab Simulink environment and practical research.

Results. The use of correction units, including those based on fuzzy logic, led to the elimination of the bridge tilt, reducing it to almost zero, and reducing the amplitude of elastic vibrations in the bridge truss to 45 percent.

Conclusion. The use of control systems with correction units, including those based on fuzzy logic, allows eliminating the desynchronization of the speeds of movement of the bridge supports of the bridge crane, which reduces the load on the metal tructure of the crane, reduces the wear of the wheel flanges and crane tracks, and increases the reliability of the crane.

Relevance. Distribution networks account for the largest share of Russia's power grid. The most common fault type in these networks is a single-phase ground fault. Selective identification of the faulty cable line can prevent its escalation into a three-phase fault, improving power supply reliability.

Purpose. A multiparameter method of ground fault protection uses several electrical quantities to determine the network mode. This method makes the protection selective and more sensitive. Different electrical quantities are of different value for the mode recognition task. The goal of the research is to study the parameters of current and voltage that are used for relay protection. Investigation of the ability to recognize network mode based on this parameters.

Methods. We obtained statistics by using simulation modeling of the cable network in the Matlab software package in the Simulink expansion package in all possible modes. And then we used discrete Fourier transform of the full period to obtain filtred harmonics and quadrature components of the values of zero-sequence currents and voltages.

Results. The article describes the block and functional diagrams of measuring elements that uses the dependencies of electrical quantities are proposed. The article determines the areas formed by electrical quantities on the graph in different modes such as internal and external steady-state single-phase ground faults and arc intermittent single-phase ground faults. The graph consists of the dependence of two electrical quantities. It was also revealed that the areas of different modes have mutual intersections.

Conclusions. The results of the study are suitable for the implementation of multiparameter protection.

Relevance. Rural 0.4 kV electrical networks are characterized by low protection against emergency currents, especially remote single-phase short circuits, which have values comparable to load currents. The protective devices at the beginning of the power line do not work on these currents. An increase in the protection of the power transmission line from these modes can be achieved through the use of network partitioning devices installed in the dissection of the line. These include devices for sectioning lines with desoldering – multi-contact switching systems. The values of currents and voltages at the point of installation of the sectioning devices differ from the currents and voltages at the beginning of the line in different modes. There are also special features and values of currents and voltages during emergency modes in the desoldering and continuation of the main line. This allows us to create new, more reliable methods and algorithms for protecting the 0.4 kV electrical network from emergency conditions and identifying the areas where they occurred.

The purpose. Development of a method for protecting rural 0.4 kV electrical networks from short circuits using a partitioning device and an algorithm for its implementation. RESEARCH METHODS. During the development of a method for protecting rural 0.4 kV electrical networks from short circuits and an algorithm for its implementation, the results of computer modeling of emergency modes of operation of a rural 0.4 kV electrical network were used. The dependencies obtained during modeling formed the basis for the development of the method. The method allows you to identify the type of short circuit and the section of the line where it occurred. When developing an algorithm for protecting rural 0.4 kV electrical networks from short circuits, the provisions of GOST 19.701-90 «Schemes of algorithms, programs, data and systems were used. Conditional designations and rules of execution».

Results. A method has been developed to protect a 0.4 kV power transmission line with desoldering from short circuits, identify the type of short circuit and the section of the line where it occurred. An algorithm for implementing this method has been developed.

Conclusion. The results obtained will be used in the development of technical means for sectioning rural electrical networks of 0.4 kV and substantiating their operating settings.

Relevance. is improving the efficiency of decision support for the trouble-free operation of responsible electrical equipment requires improved methods and algorithms for fault detection, which is undoubtedly an urgent task.

The purpose. is to develop an effective and reliable procedure for the holistic analysis, assessment and prediction of possible malfunctions in oil-filled transformer equipment, as one of the critical assets of an energy company.

Methods. When solving problems, the dissolved gas analysis (DGA) method is used as the most informative in terms of the technical condition operational assessment of the transformer and detection of signs of its deviations from the norm, as well as an improved method for constructing and event tree analysis (ETA), which combines the traditional structure of cause-and-effect relationships with components for calculating the equipment health index.

Results. The improvement of the event tree analysis method concerns the introduction of a quantitative measure of the importance of cause-effect relationships at each of the hierarchical levels, with the determination of the probabilities of outcomes of each of the initiating events based on a given root event probability. The role of a quantitative measure is performed by a weighting coefficient system obtained using the matrices of paired comparisons of Saati for each ETA level. A logical and probabilistic ETA model has been formed, which allows not only to record the interrelationships between events and the sequence of their occurrence, but also to rank them according to the degree of influence on the final undesirable outcome. Calculations confirming the proposed approach effectiveness have been performed.

Conclusion. A logical-probabilistic ETA model has been obtained, which provides, along with the DGA method, a holistic analysis, assessment and prediction of possible malfunctions of oil-filled transformer equipment. An effective procedure has been developed for constructing and analyzing data sets using expert assessments and components for calculating the equipment health index. The possibility of effective application of the developed model is demonstrated by analyzing the causes of monotonous excess of the boundary concentrations of carbon monoxide and carbon dioxide dissolved in the oil of the studied transformers.

Relevance. Unreasonable overhead power line outages are typically associated with flashover of line insulation due to contamination and moisture. Partial discharges on the insulation surface are fairly reliable indicators of dangerous levels of contamination and can be detected in a variety of ways. Remote non-invasive methods have become more popular for preventive control of the characteristics of surface partial discharges (SPD), they are based on the registration of acoustic and electromagnetic signals of various partial frequency ranges, as well as optical radiation in the infrared (IR) and ultraviolet (UV) parts of the spectrum. Daytime UV flaw detectors are considered promising for the realization of UV-inspection, they are also known by other names: UV cameras, UV visualizers, UV scanners, etc. These devices register corona radiation and surface partial discharges in the range of 240-280 nm and can be used in the daytime due to light filters cutting off solar radiation. Currently clear relationships between the characteristics of discharge processes and the degree of contamination of the insulation and its moisture-discharge characteristics have not been obtained even in laboratory studies. Of course, the complexity of the processes plays a determining role in that, but insufficient knowledge of the properties of the equipment and the influence of external factors contribute on the UV-inspection results.

Purpose. To investigate the transmission characteristics of several types of UV flaw detectors and to evaluate the influence of the propagation ambience on UV-inspection results. Restrictions on the range of equipment settings and on the conditions for conducting UV-inspection in the field should be formulated based on the research results.

Methods. Experimental research methods were used both in laboratory conditions and in the process of UV-inspection of real objects to solve the tasks.

Results. Relationships between the readings of the photon counter and the area of UV-radiation from the input gain of UV flaw detectors have been experimentally established. Double impact of the effect of water vapors and dust particles on the result of recording the intensity of discharges was revealed. The practical application of the obtained results in ultraviolet inspection makes it possible to improve the diagnostic process, thereby increasing the reliability of electrical devices.

Relevance. of the research is to develop a methodology for the Kalman filter tuning for the problem of synchronous generator control in the operation mode. This allows us to synthesize optimal and adaptive controllers. The complication consists in the absence of the possibility of direct measurement of all the necessary quantities.

The Purpose. To determine the approach of Kalman filter tuning for the control problems in the operating mode of a synchronous generator. To determine the filtering quality of the output signals and estimation of  the operating parameters with disturbance in the input channels and noise in the measuring ones.

Methods. To achieve the aim, the methods of mathematical modeling implemented by MatLab/Simulink tools were used. The methods of mathematical statistics and optimization were used.

Results. The paper describes the algorithm for Kalman filter tuning that allows to determine the vector of state variables without linearizing the synchronous generator model. The research was conducted on the influence of noise covariance matrix Q and R for quality filtration and parameters estimation of rotor angle and speed. For the research, a digital model with a synchronous generator from the MatLab/Simulink library was designed and another one was designed with a generator in the state space.

Conclusion. It has been established that matrices Q and R influence on the speed of movement of the estimated parameters by the true values. If the matrices components are equal the power spectral densities of the disturbances and noise in these measuring channels, the measurement error will tend for zero. The same result is obtained if the components of the Q and R matrices do not have the necessary power spectral densities of disturbances and noise, but at the same time, between the components of the Q and R matrices, it is necessary to maintain the same proportion as when they are created by the above-mentioned method.

The Relevance of the study of combining nuclear power plants with the hydrogen complex is substantiated by the need to adapt nuclear power plants to variable energy consumption during the day in the conditions of their involvement in regulating the unevenness of daily schedules of electric load while maintaining the basic load.

Purpose. Assessment of the thermodynamic efficiency of combining a nuclear power plant with a hydrogen complex to cover the peak load in the power system, taking into account the features of the process of water electrolysis under high pressure.

Methods. Based on world experience, the mechanism of crosspenetration of hydrogen and oxygen, as well as solutions aimed at preventing this phenomenon, are analyzed. The assessment of the thermodynamic efficiency of combining NPPs with a hydrogen complex was carried out on the basis of a mathematical and thermodynamic model of the expanded thermal scheme of the NPP using the IAPWS-IF97 formulations.

Results. On the basis of the generalized analysis, the authors established and explained the regularity of the decrease in the efficiency of electrolysis with an increase in pressure due to the phenomenon of cross-penetration. Complex nomograms of the regularities of the influence of working pressure on the main characteristics of electrolysis, in particular, efficiency, specific consumption of electricity for hydrogen production, operating voltage on the cell, have been developed. It was obtained that the hydrogen complex based on high-pressure electrolysis turns out to be more efficient than the system using compressors in terms of the criteria for converting the using power into the peak power and the efficiency of the nuclear power plant.

Conclusions. The authors have developed and patented a new principle of combining nuclear power plants with a hydrogen complex based on high-pressure water electrolysis and shown its efficiency under the influence of crosspenetration of hydrogen and oxygen in comparison with the system when using compressor machines as part of a hydrogen complex.

The Relevance of the study is to develop a pilot industrial model of an anti-scale device using the principle of ultrasonic technology to prevent scale formation, based on the complex physical impact of mechanical vibrations on the liquid and the surface of pipes, by superimposing high-intensity sound vibrations on the vibrations of the ultrasonic frequency.

The Purpose. To experimentally evaluate the efficiency of a complex method of ultrasonic removal of scale deposits from the inner walls of heat exchange pipes. To consider the possibility of increasing the service life of heat exchange boilers by improving the quality of scale deposit removal from the surfaces of heat exchange pipes using ultrasonic and sound vibrations.

Methods. Practical experiments and evaluation of the effectiveness of the integrated method of ultrasonic removal of scale deposits were carried out on a pilot –industrial model of an anti-scale device mounted on a steam boiler of a boiler house.

Results. The article describes the relevance of the topic, considers the features of the developed anti-scale device and the features of its installation on the elements of the boiler heat exchanger. An experimental assessment of the effectiveness of the method of ultrasonic removal of scale deposits from the inner walls of heat exchange pipes is considered. Conclusions are made about the effectiveness of the claimed method.

Conclusion. The developed pilot-industrial anti-scale device uses the complex effect of mechanical vibrations on the liquid and the surface of pipes, which increases the effectiveness of the action to prevent and remove solid deposits from the heat exchanger. The positive effect of cleaning the internal surfaces of the heat exchanger has been established experimentally. The results obtained allow us to predict the possibility of increasing the service life of heat exchange boilers.

The heating network of the heat supply system, which has exhausted its resource, needs reconstruction. At the stage of choosing the method of relaying the heating network, there is a need to determine the most profitable reconstruction option in terms of capital and operating costs. The article proposes a methodology based on the comparison and contrast of the most significant types of costs and losses during the life cycle of heat networks: during construction, during the transportation of heat carrier, in case of leaks of heat carrier and through thermal insulation. A comparative analysis of possible options based on relative performance indicators determined as a result of processing initial, standard and calculated data is carried out using ZuluThermo and MS Excel programs. The distribution heating network and possible options for its reconstruction are considered and calculated. For each option, a design calculation was carried out to determine the diameters of pipelines in the sections and an adjustment calculation to determine the calculated values of the characteristics of the heating network. A comparison of the effectiveness of the options was performed. The most effective option is with duct-free piping in bitumen-perlite insulation with pumping mixing for the consumer, but due to the fact that the heating main passes through an industrial area, a slightly less efficient reconstruction option with above-ground piping on low supports in polyurethane foam insulation with pumping mixing for the consumer is recommended. The methodology can be used to substantiate the choice of the option for the reconstruction of the heat supply network.

Relevance. Data centers are a specialized facility that is an interconnected system of IT infrastructure, engineering infra-structure, equipment (server and network) and parts of which are located in a building or room connected to external networks, both engineering and telecommunications. Due to the significant heat generation of these systems, there is a need to increase the efficiency of cooling systems through efficient heat recovery.

The purpose. Calculation of the energy balance of a typical data center designed for operation in central Russia.

Methods. The developed energy model of a data center is a mathematical description of all energy processes in a building, including heat transfer processes, the effects of ventilation and air conditioning, the operation of lighting, electrical appliances and other equipment, and the operation of engineering systems.

Results. According to the simulation results, the specific energy consumption was 1,353 kWh/m², the specific annual cost of energy resources was 8,572.90 rubles/m². The following key results were obtained: energy consumed by data center modules – 38,399.53 MWh/year; energy consumed by IT equipment – 31,685.20 MWh/year; PUE (it represents the ratio of the total energy consumed by the data center to the energy directly used by the IT equipment) – 1.21.

Conclusion. Data on annual energy consumption, the cost of consumed energy resources and the amount of CO² released into the atmosphere during the production of energy resources were obtained. A monthly energy consumption chart has been developed by category (heating, cooling, fans, heat recovery, pumps, interior lighting, outlet equipment, servers). In the course of further research, it is planned to consider priority schemes for the utilization of thermal energy of the data center.