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.

scholarly journals A method of testing relay protection and automation involving exposure to cascading effects for improved power supply reliability and electric power system stability

Dependability ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 47-52
Author(s):  
A. M. Koniukhov ◽  
A. V. Khlebnov ◽  
V. A. Timanov
Keyword(s):  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
Power Supply ◽  
Relay Protection ◽  
Electric Power Systems ◽  
Electric Power System ◽  
System Stability ◽  
Cascading Effects ◽  
Supply Reliability

The Aim of the paper is to show that improved power supply reliability and electric power system stability are achieved by applying new methods of testing relay protection and automation (RPaA). Major cascading failures in electric power systems are caused by cascading effects, i.e., effects involving several successive effects of various nature. Cascading effects allow extending the functionality while testing RP&A and taking into account the time factor in the context of effects of various nature. Method. A method is proposed for testing relay protection and automation taking into account the cascading effect that is used in the process of development, calibration and installation of protection devices for operation in predefined modes for the purpose of improved power supply reliability and unfailing stability of electric power systems. Result. Intermittent cascading effects do not allow the relay protection and automation recover the electric power system from the post-emergency mode, thus reducing the dynamic stability to the critical level. The diagram of relay protection and automation exposure allows taking into consideration the environmental effects in the process of testing the relay protection and automation. Conclusion. The proposed method of cascading exposure as part of testing relay protection and automation can be used in the process of development, calibration and installation of electric power systems protection and will enable improved stability of electric power systems and reliability of power supply.

Models and Methods for Studying Factors Influencing the Performance of a Hybrid Guaranteed Power Supply Complex

Vestnik MEI ◽  
2021 ◽  
pp. 58-68
Author(s):  
Mikhail G. Tyagunov ◽  
◽  
Razhidin P. Sheverdiev ◽  
Keyword(s):  
Power Systems ◽  
Power Supply ◽  
Renewable Energy Sources ◽  
Operating Conditions ◽  
Parallel Operation ◽  
Hybrid Energy ◽  
Operating Modes ◽  
Energy Complex ◽  
Factors Influencing ◽  
Power Installations

The aim of the work is to study the factors influencing the composition, parameters, and operation modes of a hybrid energy complex intended for providing guaranteed power supply to consumers located in isolated and hard-to-reach areas. The article presents mathematical models of the operating modes of power installations based on renewable energy sources as part of a hybrid energy complex involving parallel operation of different types of energy storage units, with taking into account the lifecycle, technical and process features of their functioning in isolated power systems. A 3D model of the hybrid energy complex has been developed, using which its performance can be studied under operating conditions close to real ones. In addition, a methodology of applying the model in solving design problems concerned with substantiating the parameters of isolated systems supplying power to consumers in hard-to-reach areas has been elaborated.

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.

PARALLEL OPERATION OF HYDROGEN POWER SOURCE WITH CURRENT INVERTER AND SYNCHRONOUS GENERATOR IN SELF-CONTAINED ELECTRIC-POWER SYSTEMS OF ALTRENATING CURRENT

2017 ◽  
pp. 81-91
Author(s):  
Anatoliy Burkov ◽  
Alexander Marykyn ◽  
Victor Nikityn ◽  
Alexander Tretyakov
Keyword(s):  
Power Plant ◽  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
Synchronous Generator ◽  
Power Source ◽  
Electric Power System ◽  
Parallel Operation ◽  
Power Sources ◽  
Current Inverter

Objective: The data on the synthesis of a combined electric power source for a self-contained electric-power system with a diesel generator (turbo-generator) and hydrogen power source was presented in the article. Objective: To justify the structure and parameters of a power channel of a self-contained electric power plant based on power augmentation with parallel operation on the total load of two electric power sources – synchronous generator and hydrogen power source. Methods: Mathematical modeling of the main power processes was applied, including the processes of active and reactive power distribution control in a self-contained electric power system with parallel operation of synchronous generator and hydrogen power source. Results: The tasks of structural synthesis of a combined power plant with current-based electronic inverter application, as well as justifications of power-efficient operation criteria and control algorithms of a self-contained electric power system with minimized power interchange between synchronous generator and current inverter were set and solved. Practical importance: New results are recommended to use in the design of power systems with improved technical and economic as well

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 Method of Estimating Uncertainty as a Way to Evaluate Continuity Quality of Power Supply in Hospital Devices

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 486
Author(s):  
Marek Stawowy ◽  
Adam Rosiński ◽  
Jacek Paś ◽  
Tomasz Klimczak
Keyword(s):  
Power Systems ◽  
Power Supply ◽  
Uncertainty Modeling ◽  
Supply System ◽  
Additional Advantage ◽  
Quality Models ◽  
Reliability Indicators ◽  
Electrical Devices

The article presents issues related to the determination of the continuity quality of power supply (CQoPS) for hospital electrical devices. The model describing CQoPS takes into account power redundancy. The uncertainty modeling method based on the certainty factor (CF) of the hypothesis was used to establish the single-valued CQoPS factor. CQoPS modeling takes into account multidimensional quality models and physical stages of power. The quality models take into account seven dimensions that make up CQoPS (availability, appropriate amount, power supply reliability, power quality, assurance, responsiveness, security). The model of power stages includes five of these stages (power generation, delivery to recipient, distribution by recipient, delivery to device, power-consuming device). To date, when designing hospital power systems, the applied reliability indicators revealed limitations because they do not consider all the possible factors influencing the power continuity. Estimating the supply continuity quality with the use of the uncertainty modeling proposed in this article allows for taking into account all possible factors (not just reliability factors) that may affect supply continuity. The presented modeling offers an additional advantage, namely, it allows an expanded evaluation of the hospital supply system and a description using only one indicator. This fact renders the evaluation of the supply system possible for unqualified staff. At the end of the article, some examples of calculations and simulations are presented, thus showing that the applied methods give the expected results.

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.

BASIN CONFIGURATION OF A SIX-DIMENSIONAL MODEL OF AN ELECTRIC POWER SYSTEM

2002 ◽  
Vol 12 (06) ◽  
pp. 1333-1356 ◽  
Author(s):  
YOSHISUKE UEDA ◽  
HIROYUKI AMANO ◽  
RALPH H. ABRAHAM ◽  
H. BRUCE STEWART
Keyword(s):  
Power Systems ◽  
Power System ◽  
Initial Conditions ◽  
Electrical Power ◽  
Practical Importance ◽  
Intervention Strategy ◽  
Basins Of Attraction ◽  
Electric Power System ◽  
Point Of View ◽  
Electrical Power System

As part of an ongoing project on the stability of massively complex electrical power systems, we discuss the global geometric structure of contacts among the basins of attraction of a six-dimensional dynamical system. This system represents a simple model of an electrical power system involving three machines and an infinite bus. Apart from the possible occurrence of attractors representing pathological states, the contacts between the basins have a practical importance, from the point of view of the operation of a real electrical power system. With the aid of a global map of basins, one could hope to design an intervention strategy to boot the power system back into its normal state. Our method involves taking two-dimensional sections of the six-dimensional state space, and then determining the basins directly by numerical simulation from a dense grid of initial conditions. The relations among all the basins are given for a specific numerical example, that is, choosing particular values for the parameters in our model.

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