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No 4 (2024)
Articles
Ensuring balance reliability in planning the development of electric power systems: methodological, informational and regulatory content
Abstract
The stages of improving the methodological and model support balance reliability problem of electric power systems in recent years from the standpoint of substantiation reservation levels are considered. The analysis new methodological instructions for the design development of energy systems and possible impact of their application on decisions in modern conditions are given the analysis of developed and approved by the Russian Ministry of Energy.
3-18
Fault location on overhead power lines using multi-hypothesis sequential analysis and the Armitage algorithm
Abstract
The use of modern methods for determining the fault location (FL) on overhead power lines (OHРLs), which have high accuracy and high speed, allows you to quickly find and repair damage. Various physical principles and algorithms for calculating the distance to the site of damage are used in FL OHРLs devices from different manufacturers. Some of algorithms for FL on OHРLs use the emergency mode parameters (EMP), other algorithms use measurement results based on wave methods. Many random factors that determine the magnitude of the error in calculating the distance to the FL affect the operation of FL devices by EMP. Methods based on deterministic procedures used in well-known FL devices for OHРLs do not take into account the influence of random factors, which significantly increases the time to search for the fault. The authors have developed a new method of FL on OHРLs using multi-hypothesis sequential analysis and the Armitage algorithm. The task of recognizing a faulted section of an OHРL is formulated as a statistical problem. To do this, the inspection area of the OHРL is divided into many sections, followed by the implementation of the procedure for FL. The developed method makes it possible to adapt the distortions of currents and voltages on the emergency mode oscillograms to the conditions for estimating their parameters. The results of the calculations proved that the implementation of the developed method has practically no effect on the speed of the FL algorithm for the OHРL by EMP. This ensures the uniqueness of determining the faulted section of the OHРL under the influence of random factors, which leads to a significant reduction in the inspection area of the OHРL. The application of the developed method in FL devices for OHРLs will ensure the required reliability of power supply to consumers and reduce losses from power outages by minimizing the time to search for a fault.
19-35
Features of power consumption management in complex production systems
Abstract
Solving the problems of optimizing modes and power consumption management in complex production systems is closely related to the availability of sufficient and reliable information about the features of the technological process. The features of non-stationary production modes and the possibilities of power consumption management in these conditions are considered. The results of the analysis of power consumption modes are obtained on the basis of taking into account a number of random factors determined by both internal and external circumstances, provided that the production plan (task) is mandatory. The application of the theory of emissions of random processes to increase the reliability of the initial information is justified. The necessity of further investigation of the features of technological processes in complex production systems based on the probabilistic structure and random functions is substantiated. This is due to the fact that the radiation characteristics are physically visible, they are quite easy to measure, and in many tasks, they allow you to make the transition from analog to digital representation of information simultaneously with measurements.
36-50
The effect of projected conditions of expansion planning in the electric power industry on regional disparities in the cost of electricity
Abstract
Projections of possible dynamics of generation costs and electricity prices are of paramount importance for strategies and programs of energy sector development. They give insight into the competitiveness of various types of power plants and serve as an important benchmark for making investment decisions. The price of electricity is one of the key metrics of the country’s energy and economic security. This article proposes a step-by-step approach to estimating the probable value of this metric as part of long-term projections. The approach involves optimizing the expansion planning of the electric power industry as well as determining and comparing the average and marginal costs of power generation in different regional power supply systems under uncertainty. We present the results of modeled calculations for the purpose of assessing regional disparities in both the cost of electricity and its response to different scenarios. We also note that the assumed baseline scenario follows closely «The Master Plan of Placement of Electric Power Industry Facilities to 2035».
51-63
Improved method for calculating fuel burnout in pulverized coal furnaces
Abstract
An improved method of engineering calculation of the degree of burnout of pulverized solid organic fuel in the flare furnaces of steam boilers is proposed, taking into account the kinetics of the processes of moisture evaporation, the release of volatile substances with a separate assessment of individual gaseous components and tar release and their combustion, secondary cracking of tars, combustion and gasification of coke residue, conversion of mineral part of the fuel, which allows for assessment and control of the implementation of material balances of individual stages, stages and, in general, the entire gross process of coal combustion, and ultimately an adequate determination of the magnitude of heat losses with mechanical and chemical incompleteness of combustion. Methodological provisions have been developed to take into account the kinetic and diffusion processes of the thermochemical transformation of coal to establish a quantitative relationship between the temperature-time characteristics of the combustion of pulverized coal particles and the local parameters of the combustion process. The technique is implemented in the form of specialized algorithmic and software and makes it possible to assess the degree of fuel burnout, both for the active combustion zone and for zones located in the cooling chamber of the combustion space during design and operational adjustment work.
64-87
Numerical study of convective heat transfer between core and steam generator in severe accident with loss of heat removal to secondary side of VVER reactors
Abstract
The article discusses the possibility of overheating and failure of heat exchanging tubes in VVER steam generators in the course of severe accidents. The importance of this phenomenon is due to the risk of bypassing the containment by radioactive substances. Natural convection of superheated steam in the hot leg of the main circulation loop is considered as the major mechanism for heat transfer from the core to steam generators. To model convective flows and steam temperature distribution in a system, three-dimensional CFD codes are used. The simulation results demonstrate that the intensity of convective heat transfer from reactor to hot collector of steam generator is insufficient for significant heating and catastrophic degradation of strength of the heat exchange tubes material.
88-109