scholarly journals Research of current distribution by phases in asynchronous electric motor with a combined winding

2022 ◽  
Vol 23 (5) ◽  
pp. 172-183
Author(s):  
A. E. Savenko ◽  
P. S. Savenko
Keyword(s):  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
Electric Propulsion ◽  
Experimental Studies ◽  
Negative Influence ◽  
Electric Power System ◽  
The Arctic ◽  
Diesel Generator ◽  
Power Oscillations

THE PURPOSE. Consider the use of propeller electric installations as part of ship electrical complexes with a single electric power system. Highlight the rudder drives as a special type of electric propulsion of ships in northern latitudes. Investigate unified electric power systems with a propeller electric installation for the existence of power exchange oscillations in them. Propose methods and means for eliminating power oscillations in such systems.METHODS. To carry out the research, a single electric power system with electric rudder propellers of the world's only asymmetric icebreaker Baltika was considered. All the main elements of such system have been analyzed in detail. Experimental studies were carried out aimed at studying the operating modes of a unified electric power system.RESULTS. Experimental oscillograms of currents of parallel operating diesel-generator sets in different modes have been obtained. The existence of exchange and in-phase power oscillations during the operation of the unified electric power system of the icebreaker "Baltika" is noted. The data on the negative influence of power oscillations on the operation of the electrical complex of the icebreaker are presented.CONCLUSION. The use of ice-class sea vessels is an extremely important task for the Russian Federation. The installation of blocks that eliminate exchange and in-phase power oscillations will improve the reliability and efficiency of the use of marine vessels with electric rudder propellers when servicing hydrocarbon production on the Arctic shelf.

scholarly journals Application of Dynamic Fault Tree Analysis to Prioritize Electric Power Systems in Nuclear Power Plants

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4119
Author(s):  
Sejin Baek ◽  
Gyunyoung Heo
Keyword(s):  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
Dynamic Characteristics ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Electric Power System ◽  
Diesel Generator ◽  
Fault Trees

Because the scope of risk assessments at nuclear power plants (NPPs) is being extended both spatially and temporally, conventional, or static fault trees might not be able to express failure mechanisms, or they could be unnecessarily conservative in their expression. Therefore, realistic assessment techniques are needed to adequately capture accident scenarios. In multi-unit probabilistic safety assessment (PSA), fault trees naturally become more complex as the number of units increases. In particular, when considering a shared facility between units of the electric power system (EPS), static fault trees (SFTs) that prioritize a specific unit are limited in implementing interactions between units. However, dynamic fault trees (DFTs) can be available without this limitation by using dynamic gates. Therefore, this study implements SFTs and DFTs for an EPS of two virtual NPPs and compares their results. In addition, to demonstrate the dynamic characteristics of the shared facilities, a station blackout (SBO), which causes the power system to lose its function, is assumed—especially with an inter-unit shared facility, AAC DG (Alternate AC Diesel Generator). To properly model the dynamic characteristics of the shared EPS in DFTs, a modified dynamic gate and algorithm are introduced, and a Monte Carlo simulation is adopted to quantify the DFT models. Through the analysis of the DFT, it is possible to confirm the actual connection priority of AAC DG according to the situation of units in a site. In addition, it is confirmed that some conservative results presented by the SFT can be evaluated from a more realistic perspective by reflecting this.

scholarly journals A Novel Methodology for Adaptive Coordination of Multiple Controllers in Electrical Grids

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1474
Author(s):  
Ruben Tapia-Olvera ◽  
Francisco Beltran-Carbajal ◽  
Antonio Valderrabano-Gonzalez ◽  
Omar Aguilar-Mejia
Keyword(s):  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
Large Scale ◽  
Short Circuit ◽  
Dynamic Performance ◽  
Low Frequency ◽  
Electric Power System ◽  
Design Stage ◽  
Positive Interaction

This proposal is aimed to overcome the problem that arises when diverse regulation devices and controlling strategies are involved in electric power systems regulation design. When new devices are included in electric power system after the topology and regulation goals were defined, a new design stage is generally needed to obtain the desired outputs. Moreover, if the initial design is based on a linearized model around an equilibrium point, the new conditions might degrade the whole performance of the system. Our proposal demonstrates that the power system performance can be guaranteed with one design stage when an adequate adaptive scheme is updating some critic controllers’ gains. For large-scale power systems, this feature is illustrated with the use of time domain simulations, showing the dynamic behavior of the significant variables. The transient response is enhanced in terms of maximum overshoot and settling time. This is demonstrated using the deviation between the behavior of some important variables with StatCom, but without or with PSS. A B-Spline neural networks algorithm is used to define the best controllers’ gains to efficiently attenuate low frequency oscillations when a short circuit event is presented. This strategy avoids the parameters and power system model dependency; only a dataset of typical variable measurements is required to achieve the expected behavior. The inclusion of PSS and StatCom with positive interaction, enhances the dynamic performance of the system while illustrating the ability of the strategy in adding different controllers in only one design stage.

scholarly journals Determination of reliability of power supply of ship's responsible power receivers

2020 ◽  
pp. 22-26
Author(s):  
С.Е. Кузнецов ◽  
Н.А. Алексеев ◽  
А.А. Виноградов
Keyword(s):  
Power Systems ◽  
Power System ◽  
Power Supply ◽  
Electric Power System ◽  
Time To Failure ◽  
Parallel Operation ◽  
Diesel Generator ◽  
Operating Modes ◽  
Reliability Indicators ◽  
Supply Reliability

Изложена методика расчета показателей безотказности электроснабжения (вероятности безотказного электроснабжения и средней наработки до отказа) ответственных приемников морского судна, подключаемых к аварийному электрораспределительному щиту. Методика реализована применительно к судовой электроэнергетической системе с тремя источниками электроэнергии – двумя основными дизель-генераторными агрегатами, подключенными к главному электрораспределительному щиту, и одним аварийным дизель-генераторным агрегатом, подключенным к аварийному электрораспределительному щиту. Рассмотрены различные режимы работы судовой электроэнергетической системы: при работе до первого отказа одного основного дизель-генератора, при параллельной работе двух основных дизель-генераторов, при работе одного аварийного дизель-генератора; а также после обесточивания с учетом возможности последующего включения резервного или (и) аварийного дизель генератора. Методика, с соответствующими корректировками, может быть использована для расчета показателей безотказного электроснабжения в судовых электроэнергетических системах другой комплектации. Расчет показателей безотказности электроснабжения необходим при проектировании для обеспечения требуемого уровня надежности электроснабжения судовых приемников электроэнергии, а при эксплуатации – для предупреждения отказов и планирования технического обслуживания и ремонта элементов судовых электроэнергетических систем. The methodology for calculating the indicators of the reliability of power supply (the probability of failure-free power supply and the mean time to failure) of critical receivers of a sea vessel connected to the emergency electrical switchboard is presented. The technique is implemented in relation to a ship power system with three sources of electricity - two main diesel generator sets connected to the main electrical switchboard, and one emergency diesel generator set connected to an emergency electrical switchboard. Various operating modes of the ship's electric power system are considered: during operation until the first failure of one main diesel generator, during parallel operation of two main diesel generators, during operation of one emergency diesel generator; as well as after de-energizing, taking into account the possibility of subsequent switching on of the backup and / or emergency diesel generator. The technique, with appropriate adjustments, can be used to calculate indicators of reliable power supply in ship power systems of a different configuration. Calculation of power supply reliability indicators is necessary during design to ensure the required level of power supply reliability for ship power receivers, and during operation - to prevent failures and plan maintenance and repair of elements of ship power systems.

Integral Models of Developing Electric Power Systems

2013 ◽  
Vol 2 (4) ◽  
pp. 44-58 ◽  
Author(s):  
E. V. Markova ◽  
I. V. Sidler ◽  
V. V. Trufanov
Keyword(s):  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
System Development ◽  
Electric Power Industry ◽  
Electric Power System ◽  
Integral Model ◽  
Volterra Equations ◽  
Prony Method ◽  
Optimal Service

The first part of the paper is devoted to the problem of optimal control in the area of electric power industry which is described on the basis of a one-sector variant of Glushkov integral model of developing systems. The authors consider the ways uncertain conditions of future electric power system development influence the optimal service life. The results of calculations for the Unified Electric Power System of Russia are presented and analyzed. The second part of the paper deals with the application of Prony method to identification of the Volterra equations in the two-sector models of developing systems. The authors suggest a numerical method for identifying the efficiency function parameters. An illustrative example is given.

scholarly journals Modeling and simulation of transients in electric power systems using hybrid system theory

2019 ◽  
Vol 24 ◽  
pp. 02012
Author(s):  
Yury Shornikov ◽  
Evgeny Popov
Keyword(s):  
System Theory ◽  
Power Systems ◽  
Power System ◽  
Mathematical Models ◽  
Modeling And Simulation ◽  
Electric Power ◽  
Hybrid System ◽  
Electric Power Systems ◽  
Electric Power System ◽  
Simulation Environment

Transients in electric power systems are of great interest to power engineers when designing a new or maintaining an existing system. The paper deals with using hybrid system theory for modeling and simulation of an electric power system with controllers. The presented technique is rather convenient and recommended as mathematical models of transients in electric power systems with controllers in general contain both continuous and discrete components. The modeling and simulation were carried out in the modeling and simulation environment ISMA, which is briefly presented in the paper.

scholarly journals A Modular Neural Network Scheme Applied to Fault Diagnosis in Electric Power Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-13
Author(s):  
Agustín Flores ◽  
Eduardo Quiles ◽  
Emilio García ◽  
Francisco Morant ◽  
Antonio Correcher
Keyword(s):  
Fault Diagnosis ◽  
Power Systems ◽  
Power System ◽  
Transmission Line ◽  
Electric Power ◽  
Diagnostic System ◽  
Specific Area ◽  
Electric Power Systems ◽  
Electric Power System ◽  
Power Network

This work proposes a new method for fault diagnosis in electric power systems based on neural modules. With this method the diagnosis is performed by assigning a neural module for each type of component comprising the electric power system, whether it is a transmission line, bus or transformer. The neural modules for buses and transformers comprise two diagnostic levels which take into consideration the logic states of switches and relays, both internal and back-up, with the exception of the neural module for transmission lines which also has a third diagnostic level which takes into account the oscillograms of fault voltages and currents as well as the frequency spectrums of these oscillograms, in order to verify if the transmission line had in fact been subjected to a fault. One important advantage of the diagnostic system proposed is that its implementation does not require the use of a network configurator for the system; it does not depend on the size of the power network nor does it require retraining of the neural modules if the power network increases in size, making its application possible to only one component, a specific area, or the whole context of the power system.

scholarly journals Application of Synchrophasor Measurements for Improving Situational Awareness of the Power System

2018 ◽  
Vol 55 (2) ◽  
pp. 3-10
Author(s):  
A. Obushevs ◽  
A. Mutule
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
Real Time ◽  
Situational Awareness ◽  
Renewable Energy Sources ◽  
Electric Power System ◽  
Energy Sources ◽  
Scada Systems

Abstract The paper focuses on the application of synchrophasor measurements that present unprecedented benefits compared to SCADA systems in order to facilitate the successful transformation of the Nordic-Baltic-and-European electric power system to operate with large amounts of renewable energy sources and improve situational awareness of the power system. The article describes new functionalities of visualisation tools to estimate a grid inertia level in real time with monitoring results between Nordic and Baltic power systems.

scholarly journals A study of the transient processes in the physical model of the electric power systems with predominant part of the renewable energy sources

2021 ◽  
Vol 286 ◽  
pp. 02009
Author(s):  
Ivaylo Nedelchev ◽  
Hristo Zhivomirov ◽  
Yoncho Kamenov
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
Physical Model ◽  
Wind Power ◽  
Electric Power Systems ◽  
Electric Power System ◽  
Transient Processes ◽  
Energy Sources

The renewable energy take part in the most of the electric power systems in the modern world. The part of this type of energy in the global electric power system, as well as in the local scale, increases with the setting the stricter requirements for decreasing the level of the carbon dioxide emissions. This is the result of the newest international conventions and decision for saving the nature. By these conditions, the electric power systems are forced to work with more different types of energy sources: wind power, photovoltaic, biomass plants etc. Switching of such miscellaneous power sources, leads to complicated transient processes, which are developed due to specific electrical parameters, especially harmonic components, of the synchronous generators, photovoltaic and wind power plants. This paper represents data from measurements of the transient processes into the physical model of the electric power system with predominant part of renewable energy and assesses the applicability of the model. For conducting this study, the multichannel DAQ measurement system is used.

All-mode Validation of Calculations in the Analysis of Electric Power

2020 ◽  
Vol 11 (11) ◽  
pp. 28-37
Author(s):  
Aleksey A. SUVOROV ◽  
◽  
Alexander S. GUSEV ◽  
Mikhail V. ANDREEV ◽  
Alisher B. ASKAROV ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Differential Equations ◽  
Power System ◽  
Electric Power ◽  
Field Data ◽  
Transient Stability ◽  
Experimental Studies ◽  
Electric Power System ◽  
Adequate Model ◽  
Simulation Results

The transient stability is the main condition for reliability and survivability operation of electric power system. The transient stability analysis is an extremely complex problem. It uses the results of numerical integration of differential equations that form a mathematical model of the power system. However, the mathematical model of a large-scale power system contains a rigid nonlinear system of extremely high-order differential equations. Such system cannot be solved analytically. The simplifications and limitations are used for improving the conditionality of the power system mathematical model in time-domain simulation. It decreases the reliability and accuracy of the simulation results. In this regard, it becomes necessary to validate them. The most reliable way of validation is to compare simulation results with field data. However, it is not always possible to receive the necessary amount of field data due to many power system states and a large amount of disturbances leading to instability. The paper proposes an alternative approach for validation: using an adequate model standard instead of field data. The prototype of Hybrid Real Time Power System Simulator having the necessary properties and capabilities has been used as the reference model. The appropriate sequence of actions has been developed for validation. The adequacy of proposed approach is illustrated by the fragments of the experimental studies

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