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Последно депозирани

TECHNICAL UNIVERSITY - SOFIA: Последно депозирани

Показване на публикации 181-200 от 899

Заглавие: Експериментално определяне на допустимите граници на изменение на реактивната мощност на хидрогенератори в зависимост от загряването на крайните пакети на статора Автор: Сотиров, Димитър Кирилов; Sotirov, Dimitar Kirilov; Михов, Михо Рачев; Mihov, Miho Rachev; Баташки, Стоян; Batashki, Stoyan Дата: 2009 Резюме: In the Bulgarian electric power system are working hydro generators with total power approximately 2400 MW. They are manufactured mainly in the 60s and 70s of the past century and as a rule they don't have manufacturers P-Q diagrams which would define the reactive power work range. Modern electric power control systems require the generators ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Изследване на влиянието на асиметрично аксиално изместване на полюсите на хидрогенератори върху вибрациите Автор: Сотиров, Димитър Кирилов; Sotirov, Dimitar Kirilov; Ризов, Пламен; Rizov, Plamen; Панайотов, Ивайло Димитров; Panayotov, Ivailo Dimitrov Дата: 2009 Резюме: During hydro generator's repair done with whole disassembling of the rotor and the stator, followed by assembling the machine, possible axia displacement of the rotor and stator or uneven pole shift may occur. In these cases when the hydro generator is excited in idle running, unbalanced electromagnetic forces occur. They cause vibrations ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Моделиране на лабораторни изследвания на трансформатори с използване на MATLAB/SIMULINK Автор: Спасов, Радослав; Spasov, Radoslav Дата: 2009 Резюме: This article describes MATLAB/Simulink realization of open-circuit and short-circuit tests of Electric Machinery that are performed to identify equivalent circuit parameters. These simulation models are developed to support and enhance electric machinery education at the undergraduate level. The proposed tests have been successfully integrated ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Оптимизиране на огледални оптични системи с отчитане на многократните отражения между лампата и рефлектора Автор: Василев, Христо; Vassilev, Hristo; Ангелов, Ангел; Angelov, Angel Дата: 2009 Резюме: A optimization problem of specular reflectors is disused in the present paper. Comparison between different possible shapes of the reflectors got from different standard curves or combination of the standard curves. Accessible material is used for specular reflection with different reflection factors. For optimization a mathematical model ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Дифузен светодиоден осветител Автор: Василев, Христо; Vasilev, Hristo; Георгиев, Вълчан Тодоров; Gueorgiev, Valchan Todorov; Ганчев, Ганчо; Ganchev, Gancho Дата: 2009 Резюме: A LED luminaire with diffused light is discussed. The construction and the principle of operation of the luminaire are illustrated. The efficiency of the luminaire and the uniformity of the brightness of its illuminating surface are estimated. An influence of luminaire parameters is studied over 2d model. Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Особености при регулирането на реактивното натоварване на минивец Автор: Цонева, Деница; Tsoneva, Denitza; Цолов, Ангел Белчев; Tzolov, Angel Belchev; Крумов, Андрей Христов; Krumov, Andrei Hristov Дата: 2009 Резюме: The article considers an algorithm of the excitation regulator of synchronous generators by mini-hydro. The aim is to provide optimum economic parameters, consistent with dynamically changing requirements of the electric companies. Integral method is introduced to maintain the power factor. The proposed method ensures stable work of the ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Разпределение на реактивното натоварване на синхронни генератори от една електрическа централа при различни принципи на регулиране – математически модел Автор: Цонева, Деница; Tsoneva, Denitza; Цолов, Ангел Белчев; Tzolov, Angel Belchev; Крумов, Андрей Христов; Krumov, Andrei Hristov Дата: 2009 Резюме: The article examined a mathematical model to work as a regulator of excitation of synchronous generators from mini hydro power stations (SHPP). It is provided an opportunity for a full examination of all possible modes of synchronous generators by a power plant. Analysis of captured typical working and emergency procedures and results of ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: ’The Five Fingers of My Hand’ : Human Capital and Well-being in SMEs – Evidence from Bulgaria, Finland and Scotland Автор: Gabalova, Lidiya Petrova; McKie, Linda J. Дата: 2013 Резюме: This paper aims to explore the SME managers' understanding of, and attitudes towards human capital (HC) and well-being as factors impacting on the business performance of their organizations. Design/methodology/approach: The study from which this paper reports included qualitative data collected through 42 semi-structured interviews with ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Установка за контролируемо разтегляне на открити електрически дъги в контактни мрежи 25kv Автор: Ангелов, Иван Колев; Angelov, Ivan Kolev; Матов, Петър Иванов; Matov, Peter Ivanov Дата: 2009 Резюме: Operation of 25kV AC catenary is accompanied with emergency procedures. When in place of a short circuit there is an open electric arc, it participates in the electrical circuit with its nonlinear volt – ampere characteristic. Electric arc stretched from both high temperature and the movement of one electrode (pantograph). Installations ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Оценка на ефективността на спектралния състав на светлоизточниците в уличното осветление , Автор: Костов, Красимир; Kostov, Krassimir; Василев, Николай Иванов; Vassilev, Nikolay Ivanov; Караро, Улрих; Kararo, Ulrich Дата: 2009 Резюме: The reflection characteristics of different road surfaces have been studied in accordance with the spectral distribution of high pressure sodium and metal-halide lamps with power of 70W, 150W, 250W and 400W. The lens transmittance of the luminous flux for people at the age of 25 and 60 has also been determined. Determined by the quantity ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Минимизиране на светлиния поток на улични осветителни уредби за обслужваща, събирателна и главна улица нормирани по видимост Автор: Стефанов, Станимир; Stefanov, Stanimir Дата: 2009 Резюме: In this report is present the research for minimizing lighting flux of street luminaries for some class streets. The clime of the research is to define the minimal lighting flux of street luminaries necessary for reach lightings criterions. In this way, minimizing lighting flux we have a possibility to decrease power consumption by lighting ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Енергийноефективни светлоразпределения от тип «плосък лъч» за събирателни и обслужващи улици , Автор: Пачаманов, Ангел Саракинов; Pachamakov, Angel Sarakinov; Христов, Константин; Hristov, Konstantin; Енева, Петя; Eneva, Petia Дата: 2009 Резюме: This paper presents results of the mathematical modeling of the intensity distribution of a lighting fitting with the “flat beam” technology. The objective is to minimize the lighting fitting's luminous flux while at the same time achieving the qualitative and quantitative norms for the considered type of lighting installation. The intensity ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Оптимизиране на светлоразпределението на осветители за пешеходни зони Автор: Пачаманов, Ангел Саракинов; Pachamanov, Angel Sarakinov; Христов, Константин; Hristov, Konstantin Дата: 2009 Резюме: This paper presents results of the mathematical modeling of the intensity distribution of a lighting fittings for a single row of lamp posts and a given height at which lighting fittings hang. The objective is to minimize the lighting fitting's luminous flux so as to achieve the average iluminance determined by the norm for a given setting ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Компютърно симулиране на разпространението на високочестотни сигнали в силови кабели за средно напрежение Автор: Червенкова, Тодорка Вълева; Chervenkova, Todorka Valeva; Червенков, Атанас Георгиев; Chervenkov, Atanas Georgiev; Божков, Стоян Х.; Bozhkov, Stoyan H. Дата: 2009 Резюме: An advanced model of the power medium voltage cable for high frequency is created. Simulations of the cable model in frequency domain are made. The distributions of the impedance in frequency of the power cable by different length in border mode - opening circuit and short circuit are obtained. The change of the impedance in frequency domain ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Определяне на механичните загуби на синхронна машина по метода на самоспиране Автор: Михов, Михо Рачев; Mihov, Miho Rachev; Сотиров, Димитър Кирилов; Sotirov, Dimitar Kirilov; Баташки, Стоян; Batashki, Stojan Дата: 2009 Резюме: An implementation of selfstopping method for determining the mechanical losses of synchronous machine is presented. The survey is conducted in WEC "Krichim". With the obtained results for mechanical losses and reported data for the operating parameters of the machine in compensation regime are also defined steel losses. Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Заместваща схема на синхронна машина и еквивалентност на основните формули Автор: Божилов, Ганчо Йорданов; Bojilov, Gantcho Yordanov Дата: 2009 Резюме: In this paper an equivalent circuit of a synchronous machine for adequate description of all processes and quantity by stationary function of the machine are proposed. He corresponds of the fundamental equations of the synchronous machines of all types (salient poles, smooth poles or with variable reluctance, generators, motors, compensators) ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Към определянето на ефективната стойност на тока на еднофазните колекторни двигатели с наситена магнитна система, Автор: Божилов, Ганчо Йорданов; Bojilov, Gantcho Yordanov; Иванов, Адриан Петров; Ivanov, Adrian Petrov Дата: 2009 Резюме: In the paper a method for determining of the R.M.S. value and the first three odd harmonics of the current of single-phase commutator motors with saturated magnetic system is presented which the shape is non-sinusoidal. For this purpose a approximation of the magnetic characteristic of the motor by two parametric exponential function is ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Моделни изследвания за определяне характеристиките н въглищни потоци от складовото стопанство на ТЕЦ „Марица Изток 3” Автор: Бонев, Бончо И.; Bonev, Boncho I. Дата: 2009 Резюме: The operations in the fuel depot of TPS “Maritza East 3” are directed towards equalizing of the characteristics of the coal receipted from the opencast mine. It is possible, the realization of two strategies in this relation – a strategy purposed total “equalizing” and a strategy purposed dividing of the coal into two quality categories and ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Определяне качеството на въглищата на изхода от рудник в енергийния комплекс „Марица Изток” Автор: Бонев, Бончо И.; Bonev, Boncho I. Дата: 2009 Резюме: The preliminary information about quality of the coal entering in the fuel depot is of exceptional importance for the operation of the thermal power plant. Between mine “Troyanovo 3” and TPS “Maritza East 3”, it exist direct belt transport connection. In that case, it means, it is necessary the coal characteristics on the outlet of mine to ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA
Заглавие: Методи за научни визуализации – част 2 Автор: Георгиев, Веселин; Gueorguiev, Vesselin; Георгиева, Десислава В.; Georgieva, Desislava V. Дата: 2009 Резюме: In the last two decades, growth in volume and quantity of information is so great that new methods are needed for processing and extracting information from these 'raw' data. One of the most promising directions is the computer visualization. This survey aims to present the basic methods for the visualization of scientific information - is ... Библиотека:
TECHNICAL UNIVERSITY - SOFIA

Показване на публикации 181-200 от 899

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