PNRPU Bulletin. Electrotechnics, Informational Technologies, Control Systems

Modern energy is developing in the direction of decreasing the share of powerful generation sources in the overall energy balance and increasing the share of distributed generation of small and medium power, in particular alternative sources. In this trend, an increase in the number of small and medium-sized hydroelectric power stations (mini-hydroelectric power stations) should be noted. This is because the energy potential of small and medium-sized rivers in Russia and neighboring countries, according to various estimates, is several times higher than that for large rivers. For the effective use of this potential, one should go not along the path of creating a number of standard mini-hydroelectric power stations, but along the path of developing design systems focused on flexible production that would produce hydrogenerators for a specific place of the river, taking into account its features in terms of the flow and relief. Purpose: development of a design system for the creation of energy-efficient mini-hydroelectric power stations based on combined excitation valve machines for flexible production. Methods: finite element method for solving electromagnetic analysis problems, three-dimensional solid-state modeling method. Results: the developed design system will allow the synthesis of optimal geometry in accordance with the technical specifications of the customer. Only part of such a study is presented in the article, in particular, a description is given of the synthesis subsystem of the combined submersible water submersible hydrogenerator. The subsystem is based on the Ansys Electronics Desktop program and allows a comprehensive analysis of the electrical machine and its control system. The efficiency of the subsystem is shown in the analysis of the combined excitation generator 3 kW, 220 V, 350 rpm. Practical relevance: the created design system allows you to design an energy-efficient mini-hydroelectric power station for any required parameters, taking into account its installation in a specific place on a small and medium river. The digital double implemented by this system largely reduces the technical risks in the production of a real sample.

The reduction of the life of solar modules during their operation occurs for various reasons, one of which is their degradation due to overheating of surfaces in operating conditions at elevated air temperatures. The standard current-voltage and power characteristics of solar modules, indicated by the manufacturer, determine the values of the main energy parameters and do not always correspond to the external conditions where this solar power plant works. In this regard, it is necessary to know how much the generation of electricity will change under real operating conditions. Purpose of research: to develop a structural scheme for calculating the energy characteristics of solar modules, taking into account external parameters that affect their effective operation. Results: to solve this goal, the basic parameters of the solar module and the environment were investigated. It has been established that the temperature coefficient of power depends on environmental conditions, the type and quality of the material of the solar modules and determines the degree of their degradation, and the correct choice of the installation location of the modules ensures the reliability and durability of their work. The volt-ampere and power characteristics of the solar module were built with a change in temperature, and they were compared with the standard characteristics of the manufacturer. It is proposed to maintain the efficiency of the solar module near the point of maximum power to use a special holographic film with the functions of protecting the surface from infrared radiation. Introduction to the structural scheme of calculating the energy parameters of the solar module of the thermal protection element will allow you to adjust the energy characteristics of the modules. Practical relevance: a compiled block diagram of calculating the energy characteristics of solar modules in real operating conditions allows you to take into account all the parameters that affect the operational parameters of the modules and determine the most optimal conditions for their operation for maximum power generation.

The study is devoted to the problem of adapting of an aero gas turbine engine (ACS GTE) to the action of external and internal interference based on identification methods. The optimality of the adaptive and diagnostic functions of ACS depends on the validity of information about the current characteristics of the control object. Improving the reliability of modern digital ACS GTE is achieved through the creation of algorithmic information redundancy based on the built-in on-board mathematical model of the engine. It is proposed the design of the algorithms of the linearized adaptive on-board mathematical model of the engine (LABEM) with the function of parametric diagnostics of the gas-path. Methods: The method of the general matrix of influence coefficients (diagnostic matrix) is used, which allows to determine the deviation of unmeasured parameters using the coefficients of the influence of the efficiency of the engine nodes on its parameters depending on the operating mode. The method is based on the identification of the engine model from the results of the assessment of gas-dynamic parameters by minimizing the sum of the squares of the difference between the parameters of the mathematical model and the real engine. Based on the diagnostic results, the corrections are made to the algorithms of the mathematical model for its adaptation to changes in the control object. The study addresses the problem of ill-conditioning of diagnostic matrices. The uncertainty of the obtained systems of equations is caused by the “noise” of the model due to stochastic nature of the engine with an extended state space. Two methods of reducing the "noise" of the model are considered. The first method is based on reducing uncertain and ill-conditioned systems of equations to certain ones by choosing optimal sets of unmeasured parameters (reference plans), the number of which is chosen equal to the number of measured parameters. The second approach is based on expanding the space of engine states when a probabilistic decision is finding based on statistical modeling by using the numerical Monte Carlo methods. Results: The semi-natural experiment on an industrial electronic controller at various engine operating modes yielded unsatisfactory results. The best accuracy is achieved when evaluating the speed of the high pressure rotor, the worst - for the pressure behind the compressor. The second approach is based on statistical modeling by using the numerical Monte Carlo methods increases by 1,5-4,7 times the accuracy of identification. Discussion: The results can be used to improve the quality and reliability of fault-tolerant adaptive information systems for automatic control and diagnostics of gas turbine engines.

Durability and reliability of modern electrical devices in modern conditions. This is a fairly frequent device test, which makes it possible to obtain information about the overload capabilities of devices. Devices can operate in extreme modes, both under non-standard operating conditions, and when upgrading an existing device. The object of this study is a semiconductor device with a cooling system. Semiconductor devices have a fairly large amount of heat, and the massive parameters of the semiconductor devices themselves are small enough, which makes clear the relevance of solving the problems of efficient use of elements of such devices. Purpose: definition and systematization of the working conditions of the system. The results of the study were considered taking into account existing cooling systems, which can be used as an analog. To conduct specific experiments on electromechanical components, field experiments were conducted. For this, mathematical models have been developed [1]. After interpretation, the mathematical model was implemented by its numerical implementation [2, 3, 4] (the finite measurement method and the Ansys Fluent mathematical package were chosen), processing and formalizing the results in a convenient form for applying mathematical expressions.

Currently, despite some difficulties, the self-timed technique and the corresponding field of science proposed by D. Muller at the end of the 50s of the XX century continue to develop actively. In the A. Kamensky thesis a significant step was taken towards the fault tolerance of self-timed circuits (2017). However, the synthesis of self-timed universal logic modules has not yet been fully considered. Purpose: development of strictly self-timed generators of logical functions for one, two and three variables. Methods: Self-timed circuitry, synthesis of a self-synchronous multiplexer for two, four and eight channels using EDA for IC Kovcheg. Results: The study synthesized strictly self-timed logic function generators using 2AND-2OR-NOT elements, transition completion indicators, and hysteresis triggers. The proposed elements are almost equivalent to the LUT FPGA gates, however, they are built according to CMOS technology and implement self- timed operation, which allows them to be used in self- timed s base matrix crystals with either constants or additional memory cells configured. The simulation was performed in the EDA for IC Kovcheg system and in the NI Multisim circuit simulation system of the National Instruments Electronics Workbench Group firm and in the Microwind topological modeling system, which confirmed the operability of the proposed elements. Practical relevance: the developed elements can be used as additional universal blocks in the library of self-timed circuitry developed at the IPI RAS for basic matrix crystals produced at the MIET Technological Center.

The increase in anthropogenic load on natural water sources necessitates increasing the efficiency of wastewater treatment. The required number of natural experiments performance is excessively labor-intensive and can negatively affect the environment. Mathematical modeling is one main element in the biological wastewater treatment process study. A treatment plants technologist can provide constant values of the feed rates of activated sludge and wastewater during the day. This possibility is adequate for treatment plants that have the system of balancing tanks. Purpose: The development of a method for finding discrete optimal control and modification of the biological wastewater treatment process compartmental mathematical model. Results: I develop the modification of compartmental mathematical model with a variable structure for wastewater biological treatment process. Modifications appeared in the differential equations of the activated sludge microorganisms total concentration dynamics and oxygen concentration dynamics. The oxygen supply volumetric rate equation is in the model now. The discrete optimal control task is minimizing the biological wastewater treatment process costs while maintaining the output model concentrations of pollutants within acceptable limits. I propose the method for finding optimal control and develop the software package for numerical modeling in Python. The method consists in choosing the number of blowers turned on and the number of activated sludge pumps turned on. The computer modeling results and the model concentrations output values show the adequacy of the developed model to the process of biological wastewater treatment. There is the example of calculating of optimal control by experimental data obtained at the wastewater treatment plant in Petrozavodsk in the article. Practical relevance: The proposed mathematical model modification and the method for finding control allow to solve the forecasting and optimal control task for the biological wastewater treatment process.