scholarly journals ECONOMIC DAMAGE ASSESSMENT METHODOLOGY IN CASE OF TRANSFORMER LOAD RATIO DEVIATION

2021 ◽  
Vol 11 (3) ◽  
pp. 168-175
Author(s):  
Anton S. LUKOVENKO
Keyword(s):  
Power Transformer ◽  
Load Ratio ◽  
Minimum Cost ◽  
Electrical Energy ◽  
Load Level ◽  
Economic Damage ◽  
Load Factor ◽  
Optimal Load ◽  
Effi Ciency ◽  
Optimal Values

The aim of the study is to develop a methodology for assessing economic damage when the transformer load factor deviates. In the process of research, a method was used to determine the optimal load of a power transformer. A method for assessing economic damage in case of a deviation of its load factor has been developed. The optimal load factor of a power transformer has been determined according to the criterion of the minimum cost of money for the transformation of electrical energy. The load level of power transformers can be assessed by two criteria: by the maximum integral value of the effi ciency and by the minimum loss of money during the transformation of electricity. According to the proposed methodology, the assessment of damage is carried out when the load factor of the transformer deviates from the optimal values, for which the relative losses of electrical energy are calculated. The results obtained when evaluating energy and fi nancial and economic effi ciency show that when the load factor is overestimated relative to the optimal values, it is much more preferable to overestimate than underestimate. The reliability of the results is confi rmed by the satisfactory agreement of the calculated results with the experimental data obtained at the operating power plant.

The effect of finite deformations in the elastic stability of plane frames

1962 ◽  
Vol 266 (1324) ◽  
pp. 47-67 ◽  
Keyword(s):  
Critical Load ◽  
Failure Load ◽  
Elastic Stability ◽  
Load Level ◽  
Load Factor ◽  
Proportional Loading ◽  
Arbitrary Load ◽  
Plane Frames ◽  
The Difference ◽  
Rigid Joints

The circumstances are discussed under which orthogonal relations exist between the elastic critical modes of plane frames subjected to proportional loading. Orthogonal relations may be obtained provided the loading does not produce any components of deformation associated with any of the critical modes at arbitrary levels of the load factor, and provided no part of the structure remains statically indeterminate due to bar forces when all rigid joints are replaced by pin joints. When at arbitrary load factors, the structure deforms with components associated with any of the buckling modes, the elastic failure load is not identical with the lowest elastic critical load, although for many frames the two loads may be very close. A general expression is obtained which reveals the relation between the deformations at an arbitrary load level and the deflexions given by linear analysis. The difference between the elastic failure load and the elastic critical load is discussed, and an approximate treatment applicable to certain types of frame and associated loading is developed.

Study of power transformer loading in rural power supply systems

2021 ◽  
Vol 13 (4) ◽  
pp. 282-289
Author(s):  
I. V. Naumov ◽  
D. N. Karamov ◽  
A. N. Tretyakov ◽  
M. A. Yakupova ◽  
E. S. Fedorinovа
Keyword(s):  
Energy Efficiency ◽  
Power Supply ◽  
Rural Areas ◽  
Power Transformer ◽  
Electric Energy ◽  
Power Transformers ◽  
Electric Networks ◽  
Load Factors ◽  
Optimal Load ◽  
Supply Systems

The purpose of this study is to study the effect of loading power transformers (PT) in their continuous use on their energy efficiency on a real-life example of existing rural electric networks. It is noted that the vast majority of PT in rural areas have a very low load factor, which leads to an increase in specific losses of electric energy when this is transmitted to various consumers. It is planned to optimize the existing synchronized power supply systems in rural areas by creating new power supply projects in such a way as to integrate existing power sources and ensure the most efficient loading of power transformers for the subsequent transfer of these systems to isolated ones that receive power from distributed generation facilities. As an example, we use data from an electric grid company on loading power transformers in one of the districts of the Irkutsk region. Issues related to the determination of electric energy losses in rural PT at different numerical values of their load factors are considered. A computing device was developed using modern programming tools in the MATLAB system, which has been used to calculate and plot the dependence of power losses in transformers of various capacities on the actual and recommended load factors, as well as the dependence of specific losses during the transit of 1 kVA of power through a power transformer at the actual, recommended and optimal load factors. The analysis of specific losses of electric energy at the actual, recommended and optimal load factors of PT is made. Based on the analysis, the intervals of optimal load factors for different rated power of PT of rural distribution electric networks are proposed. It is noted that to increase the energy efficiency of PT, it is necessary to reduce idling losses by increasing the load of these transformers, which can be achieved by reducing the number of transformers while changing the configuration of 0.38 kV distribution networks.

Optimization of a Treatment System of Wastewater Streams for Electrochemical Cr(VI) Reduction: Selective versus Centralized Treatment

2018 ◽  
Vol 16 (11) ◽  
Author(s):  
Adrián López-Yañez ◽  
Jorge Ramirez-Muñoz ◽  
Alejandro Alonso ◽  
Luis G. Cota ◽  
Jhonny Pérez Montiel
Keyword(s):  
Hexavalent Chromium ◽  
Minimum Cost ◽  
Electrical Energy ◽  
Electrical Current ◽  
Electrochemical Process ◽  
Effluent Treatment ◽  
Treated Wastewater ◽  
Total Annual Cost ◽  
Optimal Solutions ◽  
Selective Treatment

Abstract The problem of the optimization of selective treatment systems of wastewater streams contaminated with hexavalent chromium [Cr(VI)] is investigated. In order to comply with the Mexican environmental norm of Cr(VI) for treated wastewater streams at minimum cost, a nonlinear programming (NLP) model for the electrochemical reduction of hexavalent chromium to trivalent chromium was developed. The model incorporates a variable reaction rate, which is a function of the Cr(VI) concentration and the electrical current density of the electrochemical process. For this purpose, a basic superstructure of the effluent treatment is proposed. The superstructure is composed of three continuous electrochemical reactors without recirculation, and it may produce either a series and/or parallel design topology. The NLP model was used to minimize the objective function, defined as the total annual cost (TAC), which includes the capital cost of each electrochemical reactor, the electrical energy cost and the cost of the treatment of the wastewater streams. In order to investigate the solution set of the proposed NLP model, i. e., to improve the possibilities of obtaining optimum solutions based on economic criteria, a multi-start algorithm was implemented. Two example problems are used to show the versatility of the model and different local optimal solutions were obtained for each case study. The results show that a selective treatment of wastewater streams based on the search of local optimal solutions yields significant savings with respect to a centralized treatment design.

scholarly journals THERMAL CONTROL OF REACTORS

2019 ◽  
pp. 145-151
Author(s):  
А. Мамонтов ◽  
A. Mamontov ◽  
К. Пушница ◽  
C. Pushnitsa
Keyword(s):  
Thermal Imaging ◽  
Electrical Energy ◽  
Thermal Control ◽  
Total Power ◽  
Economic Damage ◽  
Current Load ◽  
Nonlinearity Coefficient ◽  
Imaging Diagnostics ◽  
Current Limiting ◽  
Voltage Deviation

The article lists the types of reactors: current limiting reactors, smoothing reactor and arc suppression reactor. The principles of electrical energy conversion and methods of compensation of the electric current are described. In addition, the frequency of inspections is established including unplanned, current and capital repairs of equipment. The list is formed of the examined units, as well as the features of thermal imaging diagnostics of reactors with voltages up to and above 1000 V, including the design of a smoothed reactor with a voltage of 780 V and concrete reactor of voltage 10 kV. The thermograms of defects of contact connections are presented. The calculation of the angle dielectric loss tangent tg δ and the steady-state voltage is performed. As a result of the analysis of thermograms, the cause of defects in current limiting reactors with a voltage of 10 kV is formed. On the basis of the calculated value of tg δ, the method of reactor inspection is made; the calculation of the permissible voltage deviation based on the calculated nonlinearity coefficient is carried out. The calculation of the economic damage from the reactor failure depending on the value of the total power, current load and duration of shutdown, as well as the conclusion about the effectiveness of this type of diagnostics are made

scholarly journals Influence of smart metering systems on increasing the accuracy of calculation electrical power losses in electrical networks

2020 ◽  
Vol 220 ◽  
pp. 01026
Author(s):  
Timur Musaev ◽  
Marat Khabibullin ◽  
Ramil Kamaliev ◽  
Oleg Fedorov ◽  
Ilgiz Valeev ◽  
...  
Keyword(s):  
Low Voltage ◽  
Accurate Determination ◽  
Electrical Power ◽  
Electrical Energy ◽  
Actual Data ◽  
Load Factor ◽  
Electrical Networks ◽  
Operating Load ◽  
Using Data ◽  
Increase In Accuracy

The article discusses the possibility of using data from smart electricity meters (SEM) to increase the accuracy of calculation losses in 0.4 kV low-voltage networks. An increase in accuracy can be achieved using actual data about the load graph of electricity consumers (in this case, 6(10)-0.4 kV transformer substations are meant). To date, the operating load factor is taken equal to 0.5, which does not always correspond to the actual data. Using SEM, actual load graphs can be obtained, which enable more accurate determination of the operating load factor. Consequently, the accuracy of calculation of electrical energy losses will be increased.

Idejno rešenje regionalnog Data Centra kod Beograda napajanog iz obnovljivih izvora energije

2021 ◽  
Vol 23 (3) ◽  
pp. 10-17
Author(s):  
Ivan Vujović ◽  
Željko Đurišić ◽  
Keyword(s):  
High Voltage ◽  
Power Supply ◽  
Wind Farm ◽  
Low Voltage ◽  
Power Transformer ◽  
Renewable Energy Sources ◽  
Geographical Location ◽  
Electrical Energy ◽  
Economic Benefits ◽  
Infrastructure Development

Telecommunications and computer equipment centralisation trends for the purpose of achieving economic benefits, usage of technological innovations and new technical solutions implementation leads to the requirements for building bigger Data Centres (DCs). An increase in the size of the DC facility i.e. the number of racks inside occupied with equipment and the number of devices that enables the proper functioning of that equipment leads to necessarily power energy requirements increasing for power supply. For the DCs that require a large amount of energy, the building of their own, usually renewable energy sources (RES) is cost-effective. In such a caser, RES are primary and Power System (PS) is secondary and redundant power source. A concept of a DC primary powered from RES is presented in this paper. Generated electrical energy in RES is transmitted in PS through high voltage switch-gears (SGs) while DC is power supplied from PS through low voltage, medium voltage and high voltage SG-s. For the purpose of realisation of such facility, it is necessary to enable adequate conditions related to geographical location, physical access to the facility, possibility of connecting to the PS and possibility of connecting to the telecommunications centres. Based on carried out researches related to RESs potential, available roads, power supply infrastructure and telecommunication infrastructure, development conditions for DC on location near to Belgrade, close to power transformer station „Belgrade 20“ are analysed in this paper. From the aspect of DC power supply, proposed solution includes wind farm, solar plant and landfill gas power plant, as well as related SGs. Telecommunication connections from DC to the PS and other important telecommunication centres are provided. These connections are realised through optical cables placed next to the electrical lines and cables, and, when that is not possible, placed independently in the ground. The design of the DC interior is given and calculations of the required electrical energy for the power supply of the equipment and devices in the facility are performed. Based on calculation results, capacity calculation of the RES and calculation of SGs are performed. Design of the interior optical connections inside DC is also given. A General assessment of the investment and economics of building such DC are given at the end of the paper.

Exploring Synergy Among New Generation Technologies—Small Modular Reactor, Energy Storage, and Distributed Generation: A Strong Case for Remote Communities

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
K. A. Joshi ◽  
B. Poudel ◽  
R. Gokaraju
Keyword(s):  
Energy Storage ◽  
Distributed Generation ◽  
Electrical Energy ◽  
Local Source ◽  
Load Factor ◽  
Pressurized Water Reactor ◽  
Diesel Generator ◽  
Remote Communities ◽  
Pressurized Water ◽  
Pv Generation

Abstract With a steady rise in power demand in the remote communities in Canada, utilities are looking for new options to provide a reliable supply of electricity. While distributed generation is a promising option, scaling and firming up the capacity of distributed generators is essential. Alternatively, small modular reactors (SMRs) can be used as a prime local source of electricity for remote feeders provided they are flexible enough to respond to the fluctuations in demand. Electrical energy storage (EES) can be used as a buffer to absorb fluctuations in demand and generation, and as a critical back-up for the SMR on-site power supply system by replacing the diesel-generator sets. The synergy of SMR-EES-distributed generation can be an all-inclusive alternative with win-win situation for both the utility and remote communities. This paper discusses the technical feasibility of the proposed synergy using an example of an existing remote feeder in Saskatchewan, Canada. The integral pressurized water reactor is considered along with the photovoltaic (PV) generation in an existing remote feeder in Northwest Saskatchewan to estimate the plant load factor (LF) of the SMR with and without the PV generation and EES. The results quantify the benefit of having EES to support the SMR in hosting more PV generation in remote communities. EES when used in support of the SMR to host 60% PV penetration, the plant load factor improves by as much as 5%.

scholarly journals Analysis of Operating Modes of Oil-Immersed Power Transformers with a Voltage of 10 (6) / 0.4 kV

2021 ◽  
Vol 24 (4) ◽  
pp. 80-91
Author(s):  
A.E. Fokeev ◽  
I.N. Tumakov
Keyword(s):  
Ambient Temperature ◽  
Thermal Aging ◽  
Power Transformer ◽  
Spectral Composition ◽  
Operating Conditions ◽  
Power Transformers ◽  
Load Factor ◽  
Calculation Algorithm ◽  
Load Current ◽  
Aging Rate

The rate of thermal aging of the power transformers windings insulation depends on the effects of the electric field, mechanical stresses, temperature and processes that cause changes in these factors. A calculation algorithm is considered that allows determining the temperature of the most heated point of the windings of an oil power transformer at known values of the load current and ambient temperature. Calculation of the most heated winding point temperature and the rate of thermal aging of insulation for an oil power transformer at different ambient temperatures during the year, different values and different spectral composition of the electric load current showed that in some cases it is possible to violate the permissible operating conditions of power transformers. According to the calculation results, the dependences of the thermal aging rate of insulation on the ambient temperature are constructed, with different load parameters and different load coefficients of power transformers. For the considered modes, in the warm season, the value of the thermal aging rate of insulation significantly exceeds the nominal value. Based on mathematical models of oil power transformers with natural and forced oil circulation, expressions are obtained for determining the coefficient of reduction of the oil power transformers permissible load when the ambient temperature exceeds the normal value of 20 °C. On the basis of these expressions, for practical use, the dependences of the coefficient of reduction of the permissible load on the ambient temperature are constructed. The influence of ambient temperature must be taken into account when choosing the power of oil power transformers, for which it is assumed to operate in full redundancy mode or high load factor values (³ 0.8) in normal mode. To ensure the normative service life of the insulation of the windings, it is necessary to determine the design power of oil power transformers using the coefficient of reduction of the permissible load under the influence of higher harmonics of the current and the coefficient of reduction of the permissible load under the influence of ambient temperature.

scholarly journals On the power quality of electrical energy supplied to joint stock company “Aleksandrovsky mine”

2020 ◽  
Vol 209 ◽  
pp. 07012
Author(s):  
Oleg V. Zapanov ◽  
Lidiia I. Kovernikova
Keyword(s):  
Low Power ◽  
Power Quality ◽  
Energy Supply ◽  
Electric Energy ◽  
Electrical Energy ◽  
Electrical Equipment ◽  
Economic Damage ◽  
Joint Stock Company ◽  
Stock Company ◽  
Electric Networks

Joint Stock Company (JSC) “Mine Aleksandrovsky” is located in the Mogochinsky district of the Trans-Baikal Territory. “Mine Aleksandrovsky” concluded an energy supply agreement with JSC “Chitaenergosbyt” for the purchase of electric energy from it. In accordance with the contract, the electric energy supplier undertakes to supply electric energy that meets the requirements of the current legislation of the Russian Federation. The power quality in the Trans-Baikal Territory in most regions does not meet the requirements of State Standard 32144-2013. Suppliers and the network organization are responsible to consumers for the reliability of its electric energy supply and its quality within the boundaries of their electric networks. Despite the obligations of the contract, the electric energy supplied to “Mine Alexandrovsky” does not meet the requirements. In 2017 the ball mill engine in the shredding department of the gold recovery factory failed as a result of power outages and the supply of low power quality through the 6 kV line. The article provides information on interruptions in power supply over the years of operation of the enterprise, the results of analysis of the power quality, information on damage to electrical equipment caused by low power quality, and economic damage.

scholarly journals Evaluation of the possibility of using alternative sources of electrical energy to power auxiliaries of traction substations of power supply divisions on the example of ECHE-20 “Bronevaya”

2021 ◽  
Vol 2021 (4) ◽  
pp. 601-610
Author(s):  
Iliya A. TEREKHIN ◽  
◽  
Alexander Yu. BALAKIN ◽  
Keyword(s):  
Power Supply ◽  
Alternative Energy ◽  
Practical Importance ◽  
Electrical Energy ◽  
Railway Transport ◽  
Alternative Source ◽  
Alternative Energy Source ◽  
Effi Ciency ◽  
Traction Substations ◽  
Alternative Sources

Objective: To assess the possibility of using alternative sources of electrical energy to power auxiliaries of traction substations of power supply divisions on the example of ECHE-20 “Bronevayaˮ. Methods: Alternative energy is used on the railways. Results: Equipment was selected and a solar power plant was designed, economic effi ciency from the introduction of an alternative energy source and its payback period were calculated. Practical importance: The designed alternative source of electrical energy makes it possible to increase the energy effi ciency indicators of production processes of railway transport

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