scholarly journals Optimizing and Implementing the Switching of Motor Loads to Backup Power

2021 ◽  
Vol 21 (1) ◽  
pp. 68-74
Keyword(s):  
Mathematical Modeling ◽  
Power Supply ◽  
High Speed ◽  
Short Term ◽  
Residual Voltage ◽  
Synchronous Motors ◽  
Electromagnetic Moments ◽  
Asynchronous Motors ◽  
The Subject ◽  
Bench Testing

Current and electromagnetic moments of synchronous and asynchronous motors need to be below the star­ting values when such motors are self-starting after triggering a high-speed automatic transfer switch; this is the subject matter of this paper. A mathematical model is applied herein to find the range of permissible angle of backup power fed to asynchronous and synchronous motors exposed to short-term power deviations; the range is a function of the angle between the residual voltage of the main power supply and the voltage of the backup. The paper further proposes methods of switching to backup power that keep the currents and electromagnetic moments of self-starting motors below the starting values; these methods can be implemented in high-speed automatic transfer switch (ATS) microprocessors. Bench testing and mathematical modeling prove the proposed methods effective.

scholarly journals A differential operation principle of the automatic bus transfer system pickup unit as a way of decreasing the emergency clearing time.a

2022 ◽  
Vol 1211 (1) ◽  
pp. 012009
Author(s):  
Nikolay Danilov ◽  
Sergey Tsyruk ◽  
Alexandr Timonin ◽  
Karam Sharafeddine
Keyword(s):  
Power Supply ◽  
High Speed ◽  
Short Circuit ◽  
Open Circuit ◽  
Synchronous Motors ◽  
New Device ◽  
Study Results ◽  
Automatic Bus Transfer ◽  
Operation Algorithm ◽  
Emergency Events

Abstract A proper choice of the design and operation algorithm of emergency control devices like high-speed bus transfer (HSBT) is only possible proceeding from a study and analysis of steady-state and transient processes in emergency modes of operation (short-circuit faults, power supply disconnection, or phase open-circuit fault). The numerical experiments for studying such modes that were carried out, using the Matlab Simulink software package, on the mathematical models of an industrial power supply system involving synchronous motors connected to it made it possible to synthesize a new differential HSBT pickup unit featuring a high-speed response to emergency events. In doing so, special attention was paid to an analysis of transient operation modes with the aim of minimizing the probability of false actuations. The obtained study results have found practical application in the HSBT devices installed at the facilities of PJSC MOSENERGO. The experience gained from the operation of a new device jointly with high-speed circuit breakers produced by the Tavrida-Elektrik state-owned corporation has demonstrated essential advantages in comparison with the conventional HSBT designs.

scholarly journals Lineamenti di infrastrutture ferroviarie

2008 ◽  
Author(s):  
Franco Policicchio
Keyword(s):  
Electric Power ◽  
Power Supply ◽  
High Speed ◽  
Design Methods ◽  
Electric Power Supply ◽  
Track Formation ◽  
Railway Engineering ◽  
The Subject ◽  
Specialist Field

Railway engineering is, at one and the same time, a specialist field and a place in which the techniques belonging to other branches of engineering are applied. This complexity is part of the fascination of the subject. This book delineates in a synthetic but exhaustive manner, the design methods for the planimetric and altimetric alignment, the characteristics of the track formation, the track equipment, the points, the peculiarities of the viaducts and the railway tunnels, the types of the lines and the stations, with the related installations for travellers and goods, the basic notions about modern systems of electric power supply and signalling, the specific features of the high speed lines, the underground railways, the tramways and the special railways. Particularly interesting and useful to consult are the legislative references, the parametric costs and the railway glossary contained in the appendix.

Motor Load Protection of Electrical Systems From the Phase Failure in the Supply Network

2020 ◽  
Vol 63 (5) ◽  
pp. 61-66
Author(s):  
Vitalii Syvokobylenko ◽  
◽  
Sergey Derkachev ◽  
Keyword(s):  
Mathematical Modeling ◽  
Power Supply ◽  
Current Level ◽  
Supply Network ◽  
Synchronous Motors ◽  
Selective Protection ◽  
Electrical Systems ◽  
Motor Load ◽  
Supply Systems ◽  
Fast Acting

The results of mathematical modeling show that during phase failure in power supply systems with asyn-chronous and synchronous motors is appear power flows interchange between individual motors and the sup-ply network, which makes it difficult to perform selective protection against exceeding the inverse sequence currents by known methods. Proposed protection on the supply input and on individual motors, based on the control of the current level of the inverse sequence and the absence of current in one of the phases. This protec-tion on the supply input is also can used as start of fast-acting automatic transfer switch. The results of success-ful tests of protection are presented.

Ensuring electrical safety of power supply systems of electrified AC railways for highspeed lines

2018 ◽  
Vol 77 (6) ◽  
pp. 337-346 ◽  
Author(s):  
A. B. Kosarev ◽  
A. V. Barch ◽  
E. N. Rozenberg
Keyword(s):  
Power Supply ◽  
High Speed ◽  
Structural Features ◽  
Electrical Safety ◽  
Safe Operation ◽  
Ballastless Track ◽  
Conventional Structure ◽  
Artificial Earth ◽  
Earth Connection ◽  
Supply Systems

Abstract. High-speed railways are fast-growing and promising type of traffic. In Russia development of high-speed railway service is associated with the solution of a number of problems, including infrastructure. Authors propose to use earth connection of the railway catenary with the help of an artificial earthing switch on currently designed high-speed line Moscow—Kazan for 2×25 kV power supply system. Taking into account requirements for electrical safety conditions for maintenance of the track and earthed catenary supports, paper justifies method for calculating allowable voltages of rail—earth points and supports of catenary. Methods takes into account structural features of ballastless track superstructure used for high-speed lines. It is estimated that the voltages admissible under the electrical safety conditions are random in nature and distributed logarithmically normal. When calculating probability of safe operation, one should take into account random nature of both permissible stresses and those actually occurring on the track. It is estimated that the probability of safe operation in traction networks of sections with ballastless track superstructure does not exceed a similar value in electrified sections with the conventional structure of a ballast prism. Feasibility of using a 2×25 kV earth system using an artificial earth connection is confirmed, recommendations on its use are given. Authors substantiate allowable values of the rail—earth voltage and catenary supports, which practically exclude the occurrence of hazardous situations for personnel maintaining the track in sections with ballastless track superstructure.

Introduction

2017 ◽  
Author(s):  
Andrew Hadfield
Keyword(s):  
Popular Culture ◽  
Early Modern ◽  
Travel Writing ◽  
Legal Discourse ◽  
Early Modern Europe ◽  
Short Term ◽  
Empirical Observation ◽  
The Subject ◽  
Modern Europe

There were few subjects that animated people in early modern Europe more than lying. The subject is endlessly represented and discussed in literature; treatises on rhetoric and courtiership; theology, philosophy, and jurisprudence; travel writing; pamphlets and news books; science and empirical observation; popular culture, especially books about strange, unexplained phenomena; and, of course, legal discourse. For many, lying could be controlled and limited even if not eradicated; for others, lying was a necessary element of a casuistical tradition, liars balancing complicated issues and short-term pragmatic considerations in the expectation of solving more problems than they caused through their deceit....

scholarly journals Long- and Short-Term Conductance Control of Artificial Polymer Wire Synapses

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 312
Author(s):  
Naruki Hagiwara ◽  
Shoma Sekizaki ◽  
Yuji Kuwahara ◽  
Tetsuya Asai ◽  
Megumi Akai-Kasaya
Keyword(s):  
Artificial Intelligence ◽  
Human Brain ◽  
High Speed ◽  
Conductive Polymer ◽  
Long Term Potentiation ◽  
Short Term ◽  
Synaptic Functions ◽  
Term Potentiation ◽  
Artificial Brain ◽  
External Stimuli

Networks in the human brain are extremely complex and sophisticated. The abstract model of the human brain has been used in software development, specifically in artificial intelligence. Despite the remarkable outcomes achieved using artificial intelligence, the approach consumes a huge amount of computational resources. A possible solution to this issue is the development of processing circuits that physically resemble an artificial brain, which can offer low-energy loss and high-speed processing. This study demonstrated the synaptic functions of conductive polymer wires linking arbitrary electrodes in solution. By controlling the conductance of the wires, synaptic functions such as long-term potentiation and short-term plasticity were achieved, which are similar to the manner in which a synapse changes the strength of its connections. This novel organic artificial synapse can be used to construct information-processing circuits by wiring from scratch and learning efficiently in response to external stimuli.

scholarly journals Influence of Hydrogeochemistry on Tunnel Drainage in Evaporitic Formations: El Regajal Tunnel Case Study (Aranjuez, Spain)

2021 ◽  
Vol 13 (3) ◽  
pp. 1505
Author(s):  
Ignacio Menéndez Pidal ◽  
Jose Antonio Mancebo Piqueras ◽  
Eugenio Sanz Pérez ◽  
Clemente Sáenz Sanz
Keyword(s):  
High Speed ◽  
Civil Engineering ◽  
Saturation Index ◽  
The Subject ◽  
Under Construction ◽  
Underground Flow ◽  
Very High ◽  
Over Time

Many of the large number of underground works constructed or under construction in recent years are in unfavorable terrains facing unusual situations and construction conditions. This is the case of the subject under study in this paper: a tunnel excavated in evaporitic rocks that experienced significant karstification problems very quickly over time. As a result of this situation, the causes that may underlie this rapid karstification are investigated and a novel methodology is presented in civil engineering where the use of saturation indices for the different mineral specimens present has been crucial. The drainage of the rock massif of El Regajal (Madrid-Toledo, Spain, in the Madrid-Valencia high-speed train line) was studied and permitted the in-situ study of the hydrogeochemical evolution of water flow in the Miocene evaporitic materials of the Tajo Basin as a full-scale testing laboratory, that are conforms as a whole, a single aquifer. The work provides a novel methodology based on the calculation of activities through the hydrogeochemical study of water samples in different piezometers, estimating the saturation index of different saline materials and the dissolution capacity of the brine, which is surprisingly very high despite the high electrical conductivity. The circulating brine appears unsaturated with respect to thenardite, mirabilite, epsomite, glauberite, and halite. The alteration of the underground flow and the consequent renewal of the water of the aquifer by the infiltration water of rain and irrigation is the cause of the hydrogeochemical imbalance and the modification of the characteristics of the massif. These modifications include very important loss of material by dissolution, altering the resistance of the terrain and the increase of the porosity. Simultaneously, different expansive and recrystallization processes that decrease the porosity of the massif were identified in the present work. The hydrogeochemical study allows the evolution of these phenomena to be followed over time, and this, in turn, may facilitate the implementation of preventive works in civil engineering.

scholarly journals Action Recognition Network Using Stacked Short-Term Deep Features and Bidirectional Moving Average

2021 ◽  
Vol 11 (12) ◽  
pp. 5563
Author(s):  
Jinsol Ha ◽  
Joongchol Shin ◽  
Hasil Park ◽  
Joonki Paik
Keyword(s):  
Action Recognition ◽  
High Speed ◽  
Moving Average ◽  
Video Clip ◽  
Visual Surveillance ◽  
Temporal Information ◽  
Feature Maps ◽  
Short Term ◽  
Accurate Analysis ◽  
Difference Images

Action recognition requires the accurate analysis of action elements in the form of a video clip and a properly ordered sequence of the elements. To solve the two sub-problems, it is necessary to learn both spatio-temporal information and the temporal relationship between different action elements. Existing convolutional neural network (CNN)-based action recognition methods have focused on learning only spatial or temporal information without considering the temporal relation between action elements. In this paper, we create short-term pixel-difference images from the input video, and take the difference images as an input to a bidirectional exponential moving average sub-network to analyze the action elements and their temporal relations. The proposed method consists of: (i) generation of RGB and differential images, (ii) extraction of deep feature maps using an image classification sub-network, (iii) weight assignment to extracted feature maps using a bidirectional, exponential, moving average sub-network, and (iv) late fusion with a three-dimensional convolutional (C3D) sub-network to improve the accuracy of action recognition. Experimental results show that the proposed method achieves a higher performance level than existing baseline methods. In addition, the proposed action recognition network takes only 0.075 seconds per action class, which guarantees various high-speed or real-time applications, such as abnormal action classification, human–computer interaction, and intelligent visual surveillance.

Sign in / Sign up

Export Citation Format

Share Document