scholarly journals The Method of Selecting Protection Devices in the Automated Design of an Electrical Complex of a Transport Vehicle

2021 ◽  
Vol 2096 (1) ◽  
pp. 012201
Author(s):  
E Fedorov ◽  
A Ferenets ◽  
A Mingazov

Abstract The article describes the mathematical and software module of computer-aided design of vehicle electric systems: selection and verification of protective devices. The following problems are solved: calculation of currents in the circuit sections of scheme for normal and directive modes taking into account the changes in the current distribution as to the modes of consumption, calculation of the currents in the circuit sections of design scheme for short-circuit modes, checking the correct choice of protection devices as to the rated current, checking the correct selection of protection device in overloads in case of electric motor loads, determining the sequence of triggering of protection devices in the modes of short-circuit and checking the selectivity of protection, checking the protection devices for resistance to short-circuit currents

Author(s):  
Dipendra K. Sinha ◽  
Michael T. McDonald

Abstract The paper describes a belt design package which works from within a commercial Computer Aided Design and Drafting package (AutoCAD) environment and utilizes FORTRAN programs for design and selection of lowest weight components for the drive system. The components used in the process are available as stock items in U.S.A. The relevant information on these products is stored in commercial database management systems such as EXCEL and LOTUS 1-2-3. Output from the package consists of scaled drawing and tabular specifications.


Author(s):  
J C Rico ◽  
S Mateos ◽  
E Cuesta ◽  
C M Suárez

This paper presents a program for the automatic design of special tools developed under a CAD/CAM (computer aided design/manufacture) system. In particular, the special tools made with standard components have been considered. Since the design of these types of tools was essentially related to the selection of their components, this paper deals with this aspect, insisting upon the selection of those components directly related to the removal of material: the toolholders or cartridges and the inserts. To select these components it is necessary to take into account not only geometrical or technological rules but also economical ones, owing to the high amount of possible components they can select. Consideration of economical aspects required the formulation of the cost equation associated with the use of these types of tools, characterized because their cutting edges coincide with different cutting velocities. Likewise, consideration of economical aspects allows the selection of the optimum cutting conditions and the cutting components to take place at the same time. Some of the geometrical and technological parameters related to the selection of cutting components are automatically identified by the system through an automatic identification of the workpiece profile.


2013 ◽  
Vol 554-557 ◽  
pp. 372-382
Author(s):  
Mariusz Skóra ◽  
Stanislaw Weglarczyk ◽  
Jan Kusiak ◽  
Maciej Pietrzyk

Computer aided design of the manufacturing technology for anchors is presented in the paper. Evaluation of applicability of various materials for anchors, as well as analysis of the influence of process parameters on the in use properties of product, were the objectives of the research. In the material part, bainitic steels were considered as an alternative for the commonly used C-Mn steels. Possibility of elimination of the heat treatment was evaluated. Rheological models for the investigated steels were developed and implemented into the finite element code for simulations of drawing and multi stage forging. Criteria for the selection of the best manufacturing chain composed dimensional accuracy, tool life and product properties. Industrial trials were performed for the selected cycle and the efficiency of this cycle was evaluated. Finally, simulations of the in use behaviour of the anchor-concrete joint were performed. On the basis of the simulations the optimization task using strength of the joint as the objective function was formulated


1995 ◽  
Vol 117 (2) ◽  
pp. 199-204 ◽  
Author(s):  
J. R. Wagner

The cost effective design of antilock brake systems for automobiles requires the use of computer aided design and analysis techniques, as well as traditional invehicle testing. An important consideration in the simulation of the vehicle and brake dynamics is the generation of the shear forces and aligning torques at the tire/road interface. Frequently, experimental tire data gathered over a limited number of road surfaces is extrapolated to test antilock brake systems on a variety of roads. However, this approach may lead to problems in correlating the simulated system performance with actual vehicle tests. In this study, nonlinear programming strategies are applied to an analytical tire model to facilitate the selection of system variables. The formulation of an optimization problem to determine these variables permits the generation of shear forces which correspond fairly well with the empirical data. Simulation results are presented and discussed for five road surfaces to indicate the overall performance of this technique.


This paper provides a step by step guide for calculation of powertrain unit including the configuration of battery pack of a two-wheeler electric vehicle. Based on the design and desired performance of the vehicle, the total resistance force, torque and power is calculated and designed in MATLAB and Simulink, which is essential for selection of electric motor. Knowing the voltage and capacity of an individual cell the configuration of battery pack is calculated and depicted in SOLIDWORKS Computer Aided Design model. A website is developed which is competent to perform the necessary calculations and display the output of the desired performance parameters.


2021 ◽  
pp. 109-117
Author(s):  
В.В. Гаврилов ◽  
В.А. Жуков ◽  
Ю.В. Лабзин

В работе предложена методика выбора состава и основных параметров двигательно-движительного комплекса морского транспортного судна, предложены критерии оценки указанного выбора. С использованием этой методики решена задача выбора числа гребных валов при проектировании транспортных судов повышенной скорости хода. Задача решена применительно к судну RO-RO типа «Сергей Киров» (проектная скорость 17 узлов) и контейнеровозу ФЕСКО «Байкал» (проектная скорость 22 узла). В качестве критериев оценки проектных решений использована совокупность величин: пропульсивный коэффициент, часовой расход топлива в главных двигателях и суммарные затраты денежных средств на покупку и эксплуатацию главных двигателей в течение расчётного срока. Второй из перечисленных критериев использован в составе относительного конструктивного коэффициента энергетической эффективности (EEDI), который по сути является величиной, характеризующей уровень выброса СО2 в атмосферу. В работе использован авторский программный комплекс ENGINES автоматизированного проектирования судового пропульсивного комплекса. В программе предусмотрен расчёт ходкости суда, параметров гребного винта, а также выбор из электронного каталога вариантов главного двигателя. Для каждого двигателя выполнена совместная оптимизация параметров гребного винта и рабочей точки двигателя с целью обеспечения минимального часового расхода топлива. Расчёты показали, что граничная проектная скорость движения судна, при превышении которой целесообразен переход от одновальной установки в двухвальной, составляет: для RO-RO – 16 узлов; для контейнеровоза – 25 узлов. The paper proposes a method for selecting the composition and main parameters of the propulsive complex of a marine transport vessel, and suggests criteria for evaluating this choice. Using this technique, the problem of selecting the number of propeller shafts in the design of increased speed transport vessels is solved. The problem is solved in relation to the RO-RO vessel "Sergey Kirov" (design speed 17 knots) and the container ship FESCO "Baikal" (design speed 22 knots). As criteria for evaluating design solutions, a set of values is used: the propulsive coefficient, the hourly fuel consumption in the main engines and the total cost of funds for the purchase and operation of the main engines during the estimated period. The second of these criteria is used as variety of the relative constructive energy efficiency coefficient (EEDI), which is essentially a value that characterizes the level of CO2 emissions into the atmosphere. The paper uses the author's software package ENGINES for computer-aided design of the ship's propulsive complex. The program provides for the calculation of the ship's seaworthiness, the parameters of the propeller, as well as the selection of the main engine from the electronic catalog of options. For each engine, the parameters of the propeller and the operating point of the engine are jointly optimized to ensure a minimum hourly fuel consumption. Calculations have shown that the limit design speed of the vessel, when exceeding which it is advisable to switch from a single-shaft installation to a two-shaft one, is: for RO-RO – 16 knots; for a container ship - 25 knots.


Author(s):  
H G Zhang ◽  
P D Webster ◽  
T A Dean

This paper describes a software module, contained within a design-for-casting package, which aids the user in designing efficient feeding systems for castings. The user can choose a shape suitable for a particular casting condition from a file containing a variety of feeder head types. The feeder heads are placed relative to the casting in positions appropriate to hot spots identified by a ‘heat centre’ module within the package. The number and size of heads are chosen with the aid of built-in rules that aid the user. The module provides a rationale for people, both skilled and unskilled, who have to design for casting. The validity of the design rules and guidelines within the module is demonstrated by casting three widely different shapes with and without feeders.


2021 ◽  
Vol 11 (1) ◽  
pp. 405
Author(s):  
Daniel Alcala-Gonzalez ◽  
Eva Maria García del Toro ◽  
María Isabel Más-López ◽  
Santiago Pindado

The increase in the installation of renewable energy sources in electrical systems has changed the power distribution networks, and a new scenario regarding protection devices has arisen. Distributed generation (DG) might produce artificial delays regarding the performance of protection devices when acting as a result of short-circuits. In this study, the preliminary research results carried out to analyze the effect of renewable energy sources (photovoltaic, wind generation, etc.) on the protection devices of a power grid are described. In order to study this problem in a well-defined scenario, a quite simple distribution network (similar to the ones present in rural areas) was selected. The distribution network was divided into three protection zones so that each of them had DG. In the Institute of Electrical and Electronic Engineers (IEEE) system 13 bus test feeder, the short-circuits with different levels of penetration were performed from 1 MVA to 3 MVA (that represent 25%, 50%, and 75% of the total load in the network). In the simulations carried out, it was observed that the installation of DG in this distribution network produced significant changes in the short-circuit currents, and the inadequate performance of the protection devices and the delay in their operating times (with differences of up to 180% in relation to the case without DG). The latter, that is, the impacts of photovoltaic DG on the reactions of protection devices in a radial distribution network, is the most relevant outcome of this work. These are the first results obtained from a research collaboration framework established by staff from ETSI Civil and the IDR/UPM Institute, to analyze the effect of renewable energy sources (as DG) on the protection devices of a radial distribution network.


2021 ◽  
Vol 267 ◽  
pp. 01053
Author(s):  
Yarong Wang ◽  
Peirong Wang

After steam expands to a certain intermediate pressure in steam turbine, it is led out of steam turbine and sent to reheater of boiler. The steam is heated to the initial temperature by constant pressure in the reheater. After that, the steam is introduced into the steam turbine and continues to expand to the exhaust steam pressure. The steam after work enters the condenser for cooling and heat release. Such a steam power cycle is a reheat cycle. The purpose of reheat cycle is to solve the contradiction that the dryness of exhaust steam decreases after the application of high parameters in steam power cycle. Through theoretical study and qualitative analysis, we know that the correct selection of reheat pressure can not only improve the steam turbine exhaust dryness, but also improve the thermal efficiency of the cycle. Reheat pressure is very important to the economy of reheat cycle and the safe operation of equipment. The correct choice of reheat pressure will affect the economy of the whole cycle.


Author(s):  
A. Yu. Kapustsinski ◽  
S. V. Kanstantsinava

The article discusses and systematizes the causes of high values of short-circuit currents in electrical networks up to 1 kV and indicates their negative consequences. A brief analysis of some current limiting methods (both with and without additional investment) is given, which makes it possible to reduce the negative effects when significant short-circuit currents occur. The variants of the implementation of these current limiting methods recommended for study at the design stage or when replacing equipment that has exhausted its resource, are considered. The advantages and disadvantages of the methods of limiting short-circuit currents described in the article are indicated. Options for connecting equipment with low power consumption to nodes of the electrical network up to 1 kV with high values of short-circuit currents are also considered. Special attention is paid to current-limiting protection devices, a detailed description of the design of some of them is given, the advantages of their use in comparison with other current-limiting methods are indicated, the corresponding graphs of the limitation of the periodic component of the short-circuit current, shock short-circuit current and thermal pulse are presented. Based on the analysis of graphic materials, the issue of ensuring the selectivity of protections is considered. The degree of prevalence of equipment with the property of current limitation is determined. A method for determining selective current-limiting protection devices is given, viz. the method of energy selectivity, the corresponding graphs for determining energy selectivity are presented. The physics allowing to determine the degree of efficiency of limiting the short-circuit current is described. Recommendations on the use of current-limiting equipment are proposed.


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