On the issue of occurrence of fire-hazardous situations with unbalanced power consumption

2021 ◽  
Vol 14 (1) ◽  
pp. 69-76
Author(s):  
I. V. Naumov ◽  
D. A. Karamov

The influence of phase current unbalance on the probability of occurrence of fire-hazardous situations in industrial premises that receive power in various power supply systems is considered. The theoretical prerequisites for the occurrence of fire-hazardous situations are described. It is shown that zero-sequence flows flowing through a neutral conductor in an unbalanced mode significantly heat it, which can lead to short circuits and conditions for the occurrence of fires. The results of studies of unbalanced conditions in Russia and abroad are presented. It is shown that the zero-sequence flows resulting from current unbalance lead to an increase in additional losses of active power and electrical energy. It is proved that additional heat losses caused by unbalanced power consumption can destroy the insulation of neutral and phase conductors, which is the main cause of short circuits and, as a result, fires. Based on the use of the Matlab graphical editor, dynamic characteristics of variations in phase and interphase currents and voltages, as well as the power loss coefficient, which characterizes the increase in heat losses, are constructed. The analysis of fires and their consequences for various objects in the Russian Federation is made. A computational unit has been developed in Matlab, which is used for calculating and plotting the dynamics of fires and their consequences over the investigated period of time. It is shown that the occurrence of fires and their consequences due to violations of the rules of operation of electrical installations occurs in any premises and sometimes reaches more than 20% of all possible causes of fires. Methods and technical means of minimizing zero-sequence currents as a means of preventing the occurrence of fire-hazardous situations are considered. The principle of operation of an automatically controlled shunt-symmetric device with a minimum resistance to zero-sequence currents is described.

Author(s):  
S. Denysiuk ◽  
T. Bazyuk

Peculiarities of estimation of total energy losses in electric networks and estimation of nature of electricity consumption in local power supply systems (LES) are given. The structure of additional electricity losses in LES in the presence of higher harmonics of current and voltage is carried out, the generalized schedule of instantaneous functions of current i(t), voltage u(t), and power p(t) on components. The offered indicators of an estimation of the performance of criterion of a minimum of losses of the electric power in LES allow to estimate levels of distortion of power processes at consideration both exchange processes, and at the analysis of additional losses of the electric power. The accuracy of measuring the integrated characteristics of energy exchange depending on the available levels of distortion of voltage and current signals is considered. It is shown that in order to take into account the influence of higher harmonics on the total power consumption, it is necessary to determine the change of Frize QFpower as an indicator of additional electricity losses in the presence of non-sinusoidal currents and voltages in at different ratios between the value of current and voltage of the first and higher harmonics. The evaluation of the efficiency of power consumption regulation using the Frize QF power at an arbitrary time interval, as well as the corresponding current distribution into active and reactive components are considered. The peculiarities of increasing the efficiency of power consumption regulation in LES at the cyclic change of generator parameters and load are analysed.


The paper investigates the feasibility of adding a liquid heater to an oil-immersed transformer. It proves that design the high efficiency of power transformers, losses due to idling and short circuits are substantial and are scattered in the environment as heat. The paper proposes a novel design that implements a liquid (coolant) heater to enable the unit not only to convert electricity, but also to generate heat. In order to analyze the feasibility of such heat recycling, the authors have developed an equivalent thermal circuit and a mathematical model thereof. Said heater can operate in two modes. In the passive mode, the coolant it contains only absorbs the heat emitted (lost) by the power transformer. In the active mode, it also receives the heat emitted due to the passage of electric current through the pipes of the heater. The paper further introduces the definition of heater efficiency. Studies have shown that up to 50 % of transformer heat losses can be recycled by heating the coolant in the heater. The paper presents the relationship between utilized heat and transformer losses, as well as heater efficiency as a function of coolant flow rate. The heater efficiency exceeds 90 % in the active mode.


Author(s):  
Yu.F. Lachuga ◽  
◽  
A.Yu. Izmailov ◽  
Ya.P. Lobachevsky ◽  
Yu.Kh. Shogenov ◽  
...  

The main results of 2020 research work performed by scientific agroengineering institutions of the Ministry of Science and Higher Education of the Russian Federation, which are under the scientific and methodological guidance of the Department of Agricultural Sciences of the Russian Academy of Sciences on the section of mechanization, electrification and automation in the development of modern machine technologies, energy-rich technology, robotic technical means and digital technologies for the production of the main types of competitive crop and livestock products, as well as on the creation of efficient energy supply systems and renewable energy in the agricultural sector of production, mobile energy sources, and management systems for mobile energy facilities in the agricultural sector based on artificial intelligence, are presented.


Electricity is one of the basic needs and it plays an important role in the community in the social and economic development. It is an essential part of our daily lives as well as electrical energy promotes economic well-being and make social life worthwhile. Most electric cooperative encounters difficulty in monitoring the power consumption in their vicinity due to limited number of field personnel. The researcher observed that there is a need for a study on the prediction ofelectric consumption for Nueva Vizcaya Electric Cooperative (NUVELCO) to establish the trend of future consumption. This study also serve basis in managerial decision making (DSS) such as; advisory to the staff for power line clearing, household inspection, and additional transformer, additional purchased of energy. This paper uses two methods, descriptive research and developmental research to analyzed present data. A Correlation Analysis and Linear Regression Analysis is used between temperature and power consumption, precipitation and electric consumption. This statistical tool is used for prediction for analyzing time series data. The researcher derived power consumption differential equation or models which can be used to determine the growth of the electrical energy consumption. Discriminant Analysis is used in Clustering and classification of a set of observations into subsets in mapping the municipalities of the possible rise and fall of power consumption.


2019 ◽  
Vol 889 ◽  
pp. 526-532
Author(s):  
Thai Viet Dang ◽  
Si Thong Dinh ◽  
Xuan Toi Bui

Currently, the world has a lot of research and practical application of intelligent building systems integrated with intelligent power systems. Because Vietnam is a country with potential for solar energy, the integrator of solar energy is being strongly developed. However, the research result of the optimization of electrical energy used by the intelligent type solar integration is rare. This paper presents the design and structure of the module of intelligent control and monitoring via wireless network integrated with the automatic solar concentration system. The system allows easy connection and operation of all electrical power sources including the dispersal solar power to ensure the efficient and lower power consumption. In addition, the solar cell system is applied the Maximum Power Point Tracking technique (MPPT), which helps to stabilize and improve the power generation efficiency of the PV panels. The test results on the module showed absorption performance of automatic solar-cell flat plate systems is raised by 20-30% and power consumption in small households reduced approximately 30%.


2018 ◽  
Vol 239 ◽  
pp. 01035 ◽  
Author(s):  
Stanislav Istomin ◽  
Artem Perestenko ◽  
Cong Dang

The paper considers the issue of organization of control of electric power consumption by electric rolling stock by visualizing information on the monitor of the driver's console. With the correct analysis of information coming on board of the electric rolling stock, the train driver makes correction of the driving modes of the train in terms of energy efficiency. In this paper, to visualize information on the efficiency of power consumption by an electric rolling stock on the route, the authors propose using an indicator diagram using a green, white, and orange gradient. The variant of output of the final information on the efficiency of power consumption of electrical energy by an electric rolling stock both within the distances operated by the locomotive crews and within the hauls to the monitor of the driver's console is presented. One of the main advantages of using the technology of visual control of electric power consumption by electric rolling stock is the promptness of correction of decision-making on the rational use of energy resources, the identification of objective reasons for the overspending of energy, and the identification of reference results for the driving of trains. The prospect of development of the research topic is the approbation and implementation of the proposed technical and technological solutions in the production, which will reduce the specific consumption and unproductive electric power losses within the boundaries of the railway accounting zones.


2018 ◽  
Vol 41 ◽  
pp. 03013 ◽  
Author(s):  
Fedor Nepsha ◽  
Roman Belyaevsky

In this paper, the authors propose an algorithm for interrelated voltage regulation in the power supply system of coal mine which allows to provide a normative voltage level and to minimize the level of active power consumption. A feature of the proposed algorithm is a separate consideration of discrete and nondiscrete variables. Nondiscrete variables are represented as a state matrix. The optimization of nondiscrete variables is performed for each state. The algorithm chooses a state with the minimal active power consumption. The obtained values of discrete and nondiscrete variables are transferred in the form of control signals to voltage regulation devices. In this case, the periodicity of the switching is determined by the resource of the on-load tap-changing device. The use of this algorithm will theoretically allow increasing the energy efficiency of power supply systems of coal mines.


2018 ◽  
Vol 239 ◽  
pp. 01033
Author(s):  
Vasily Cheremisin ◽  
Yury Demin ◽  
Alexander Komyakov ◽  
Vladimir Ivanchenko

The paper is devoted to the development of technology for reducing the consumption and losses of electrical energy of railway transport enterprises on the basis of the concept of “smart enterprise”. A design solution to the monitoring and management system for energy efficiency indicators was proposed; monitored parameters and influencing factors were determined. The application of the simulation model in the MATLAB/Simulink program for determining the set values of the monitored system parameters, namely, power losses and power factor depending on the influencing factors, is considered. The approximating equation is obtained. Specific power losses were calculated for various control options.


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