Search

The spectral characteristics of electromagnetic radiation from cloud discharges triggered by groups of model hydrometeors in an artificial thunderstorm cloud are presented on the basis of wavelet analysis. It is found that these characteristics depend on the locations of cells of different polarity relative to the ground, on the location of groups of large hydrometeors in the cloud, and the way they are combined into a common array. The characteristic frequency ranges in the spectrum of electromagnetic radiation of cloud discharges recorded on the Earth’s surface and at the height of an artificial thunderstorm cloud are determined. It is assumed that the bulk of large hailstones will modify the characteristics of the spectrum of electromagnetic radiation of cloud discharges in a thunderstorm cloud in different ways, depending on the movement of these hailstones near the areas of positive and negative charge of the thunderstorm cloud. It is found that the boundary frequencies in the spectrum of signals recorded on the Earth’s surface can reach 400 MHz, while they may achieve 1200 MHz at the height of the cloud. The risk of the impact of pulses of electromagnetic radiation from cloud discharges with the revealed spectral characteristics on digital elements of ground cyberphysical systems and aircraft in frequency ranges of mega- to gigahertz is analyzed.

Operating-lock systems are intended to prevent emergencies and injury-causing hazards at power substations. To arrange operating locks in switch and control gear (SCG) cells, it is necessary to have technical tools of no-voltage and voltage detection on conductor buses. The use of no-contact capacitance voltage detectors is an efficient way to make the installation process less labor-intensive. A matter of substantial interest is the design of a no-contact device able to indicate the absence or supply of voltage in each separate conductor bus and initiate phase rotation. The designed voltage detector uses a system of three capacitance electric- field detectors installed in the SCG opposite to the respective lines. Each of the detectors is affected by the fields generated by all the lines when energized. Thus, the output signal of each detector is the sum of partial signals conditioned by the voltage of each separate phase. Each of the three partial components in such signals is detected by digital signal processing. The operation of the detectors under uncertainty was modeled by the Monte Carlo technique in the MATLAB environment. Each imitative test with a random set of parameters results in vector responses from the detectors. The test results help draw diagrams on a complex plane for full-phase and open-phase modes. It is shown that the pertinence of signal vectors to a specific region makes it possible to unambiguously identify the absence or supply of voltage for each separate conductor bus.

The idea of the system control and monitoring of a complete 35-kV switchgear with the shielded solid insulation is presented. The switchgear is constructed in the form of two cells. One of the cells, which has a three-position sulphur hexafluoride load break–disconnecting–grounding switch with a motor-spring drive is incorporated into the switch module and includes bus and cable modules, a cell cabinet, and a control and monitoring system. The other cell contains the same elements, plus a fuse and a high-speed grounding switch. The control and monitoring system is developed in two forms, one for standard and one for digital substations. Technical characteristics and the structure of the system, as well as the execution algorithms, are given. Monitoring of the electromagnetic fields and partial discharges with the use of the various indicators and sensors, monitoring of insulation, and its temperature, as well as residual life of the switching devices and drives, are of great significance. Modbus is usually used as the automation protocol for standard substations. It allows carrying out the dispatching control and data integration into the control system, but it does not allow real-time transmission of the instantaneous values of current and voltage, RPA discrete signals, etc. In accordance with the IEC 61850 standards, all real-time commutation processes are carried out by the Ethernet technology, which is described by the IEEE 802.3 protocol and provides digital data transfer in accordance with stringent RPA requirements. Structural implementation of two system modifications in the form of the nonstandard telecommunication equipment with a temperature–humidity control system located on the top of the switchgear cabinet with the arrangement of the control, indication, and alarm element is described.

The article discusses a modification of the ant colony algorithm, which is used to solve the problem of forming the composition of multiversion software with a dynamic architecture. The algorithm was tested for a specific composition of multiversion modules. The graphical dependencies that characterize the changes in the parameters of the cost and reliability of the multiversion software complex with the specified resource constraints are presented.

The prospects for use of energy cables with cross-linked polyethylene insulation (CLPE) and switching gears with solid insulation under direct and alternating current are considered. The main developments in the work of enterprises manufacturing cable products are listed, and their main characteristics are given. The advantages of cables lines with cross-linked polyethylene insulation over cable lines with paper–oil insulation are described: increased capacity, high permissible insulation temperature, smaller cable bend radius, smaller weight–size parameters, increased service life, the possibility of being laid at low temperatures, and high environmental characteristics. The global experience and main problems of application of cross-linked polyethylene insulation cables under direct high-voltage current are analyzed. The variants of performance of the insulation and structure of 6–35 kV switching gears of different producers are studied. Some functions of switching gear, typical structures, and equipment structure are listed, and the main test modes for insulation of separated section and units of the switching gears are described. Different types of solid insulation of complete switching gears (CSGs) of medium voltage are compared: with and without a grounded shield on the surface. Reduced weight–size parameters and increased electrical safety are identified as advantages of the structure with a shield. Data on perspective Russian development in the area of complete switching gears and solid insulation are presented, and the conclusions regarding their main advantages are drawn. The basic functional of the system of control and monitoring by new-generation switching gear of the is offered.

This article presents results of research on the strength distribution of electric and magnetic fields created by a bus-bar arrangement of a linear disconnector on 110-kV outdoor switchgear (OSG). The research was carried out directly under phase line wires with a small radius and long length going out from the disconnector. The research was carried out for two linear disconnectors of OSG placed far apart from each other. The height above the ground of the bus-bar arrangement of the linear disconnector amounted to 0.5–2 m. For the bus-bar arrangement of linear disconnector placed at a height above the ground of 5 m, experimental studies of magnetic field strength under the middle and outermost phase line wires were carried out. The studies were performed at a distance of 1 m from the linear disconnector for heights above the ground within the range of 0.5–2 m. The parameters of the strength indicators of electric and magnetic fields were determined. Recommendations for location of the strength indicators of electric and magnetic fields are given. The behavior of the strengths of electric and magnetic fields under the bus-bar arrangement of the linear disconnector is determined, and the principle of indication of electric and magnetic fields under the OSG elements is specified.

The article considers a software package that allows you to form the composition of multiversion software for fault-tolerant control systems. The software implementation is based on a modified ant colony algorithm, which belongs to the class of bioinspired algorithms. The algorithm implements the search direction in order to minimize the cost of a program consisting of a set of modules. For each module, there are several versions of its implementation, developed within the framework of the multiversion programming methodology. The search direction is also implemented in order to maximize the reliability of the modular program in multiversion execution. The software implementation of the algorithm allows a number of experiments to be performed to obtain data that can be used to compare the performance of the standard and modified ant colony algorithms.

The main result of the research is the creation of a new model of multiversion design of highly reliable software systems, which allows taking into account the real-time mode in the operation of programs that are part of reliability critical applications. The problem of multiversion design of the highly reliable software systems is presented in the form of the well-known problem of covering the set, which made it possible to use bioinspired algorithms, in particular, ant colony algorithms, to solve it. The decision rule of the ant colony algorithm has been modified, which provides support for the implementation of bioinspired information technology, taking into account changes in the structure of the software system in real time. The proposed model and the performed modifications of the ant colony algorithm are the basis for the creation of new tools that implement software and algorithmic support for the effective multiversion design of the highly reliable software systems in real time.

The article presents an expert analysis of RTOS for hardware and software support of environmental monitoring technologies for hazardous production facilities, including thermal power facilities. The features of the operation of environmental monitoring systems are considered. As the main factors, climatic conditions, mechanical, thermal, chemical, and radiation effects were taken into account. An analysis of the requirements for environmental monitoring systems is carried out, their formalization is given, which fully determines the appearance of the environmental monitoring system. It is shown that the method of comparative analysis allows us to determine the feasible implementation option of RTOS for hardware and software support of environmental monitoring technologies. Expert analysis is presented for Phar Lap ETS, VxWorks and NI Linux Real-Time systems.

The impact of electric fields is a factor that had a negative effect on power plant personnel and equipment. To calculate electric fields, simplified models are used. Currently, a variety of analytical and numerical methods for the calculation of electric fields have been developed. In most cases, calculation of electric fields is very complex and the design of the analytical solution can require rough approximations, leading to significant errors. Thus, numerical methods play a large role. When different methods are used, the structures of the initial data needed for solving specific problems can be different; moreover, the number of calculations in different methods can differ significantly. The calculation of electric fields in high voltage cells is of great practical importance. For different systems that provide safety in high voltage electrical plants—in particular, in the cells of a complete distributed device—it is necessary to manage the electric fields of a complex configuration. To prevent the personnel from making mistakes, it is necessary to have sensors that detect the electric field strength coming from disconnected lines or generated in the high voltage cells. As a result, the object generating the electric field is identified and the location mode of the registering sensors is determined. Most currently existing sensors are not optimized for various power plants—in particular, for highvoltage cells. The main stages of analysis and calculation of electric fields are considered. A simplified calculation of the electric field strength distribution in the high-voltage cell is carried out. Optimal locations for electric fields sensors responding to the presence or absence of voltage on the individual elements of the high voltage cell are determined.

The article describes the requirements for medium-voltage switchgears. It shows the main advantages and drawbacks of the conventional air-insulated switchgears and the relevance of the switchgears with solid insulation and solid shielded insulation. The use of this insulation system allows to reduce significantly the size of switchgear and to improve considerably the safety of its operation. The analysis of above mentioned characteristics of insulating systems with solid insulation in switchgear with solid shielded insulation (SISS) was carried out and there were given recommendations for the use of solid insulation. There were considered the main features of the SISS solid insulation: weakly inhomogeneous electric fields; high working electric field intensity; large volume of solid dielectric; high operating temperatures; usage of compact connections of adjoining insulation systems with solid insulation. There were defined typical insulation clearances of SISS: coaxial cylinders; special connectors; cable adapters; current leads and the insulating cases in the switchgears. The analysis of the known characteristics of the cast epoxy insulation and EPDM shows that the thickness of the insulation at high voltage in different standard insulation clearances, as a rule, may differ. It was determined that in order to ensure reliable operation of the SISS it is necessary to take special measures to exclude the possibility of gas spaces presence in the solid insulation.

Requirements for electromagnetic, capacitance, and electronic voltage measuring transformers in 10- to 110-kV mains are clarified. The urgency of developing electronic-voltage transformers that will meet the requirements of upcoming international standards and have the function of standard analog output signals for actual substations is shown. Results of modeling are given that confirming that it is possible to use this innovation, which eliminates ferroresonance phenomena and PSP rearrangement and facilitates effects on equipment. Designs and specifications of 110-kV electronic transformers are given.

The article considers a method for increasing the parameters reliability of a multipoint spatial measurement during the environmental monitoring at thermal power plants. The result is achieved by using functional dependency and applying fuzzy voting by the agreed majority for decision making. The functional dependence is caused by physical processes occurring while the flue gases transformation along the length of the pipe. The proposed approach helps to compare directly the values of the measured parameter obtained at different points in space, due to their reduction using functional dependencies. This approach also can detect the faults in the sensors. The detection of failures occurs by comparing the direct readings at a given point with the readings calculated about other points.

The visual presentation of the software life cycle control model is considered in this scientific paper. A realization of the control model is connected with identifying the semantics, properties and attributes of formation stages, implementation and maintenance of software. For research themethodology IDEF0 is applied. The software lifecycle control model is obtained in a graphical notation. Functional modeling of complex processes, associated not only with development, but also with testing and long-term maintenance of onboard software, is described and presented. It is shown that visual modeling tools are able to be as an effective mean of making control decisions.

The multi-version software and problem of its building as an optimization problem are considered. The ant algorithm as a way to solve the problem of multi-version software building is presented. The results of the standard and modified ant algorithms are given and compared.

The usage of information and control systems in various fields of production and research requires a certain level of reliability in the functioning of these systems. One of the most promising and already positively proven methodologies to ensure high reliability and fault tolerance of software is multi-version designing. The greatest value this factor have in the areas where control system failure can result in significant financial and material losses, as well as harm to human health and life.

The paper considers the problem of collection, processing and control by the highly specialized information. The system offers the correct solutions for a multilingual representation of information in the Internet. It is proposed to use the implementation technology of the information control systems based on multi-agent approach.

The problem of developing an optimal structure of N-version software system presents a kind of very complex optimization problem. This causes the use of deterministic optimization methods inappropriate for solving the stated problem. In this view, exploiting heuristic strategies looks more rational. In the field of pseudo-Boolean optimization theory, the so called method of varied probabilities (MVP) has been developed to solve problems with a large dimensionality. Some additional modifications of MVP have been made to solve the problem of N-version systems design. Those algorithms take into account the discovered specific features of the objective function. The practical experiments have shown the advantage of using these algorithm modifications because of reducing a search space.

The N-version programming, as a methodology of the fault-tolerant software systems design, allows successful solving of the mentioned tasks. The use of N-version programming approach turns out to be effective, since the system is constructed out of several parallel executed versions of some software module. Those versions are written to meet the same specification but by different programmers. The problem of developing an optimal structure of N-version software system presents a kind of very complex optimization problem. This causes the use of deterministic optimization methods inappropriate for solving the stated problem. In this view, exploiting heuristic strategies looks more rational. In the field of pseudo-Boolean optimization theory, the so called method of varied probabilities (MVP) has been developed to solve problems with a large dimensionality.