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Proceedings of the Technical university of Sofia, 1995 -: Recent submissions

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Title: Моделиране и симулиране на асинхронен генератор с навит ротор Author: Лазаров, Владимир Димитров; Lazarov, Vladimir Dimitrov; Стоянов, Людмил; Stoyanov, Ludmil; Бъндева, Костадинка; Bundeva, Kostadinka; Зарков, Захари Живков; Zarkov, Zahari Zhivkov; Спиров, Димитър; Spirov, Dimitar Date: 2009 Abstract: Due to great interest in wound rotor induction machines utilization and their application in the renewable energy sources, this article presents a model of such machine in the Matlab/Simulink environment. The goal is to create an accurate model with the aid of which further performance simulations of double fed induction generator in ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Моделиране и симулиране на асинхронен генератор с накъсо съединен ротор Author: Лазаров, Владимир; Lazarov, Vladimir; Стоянов, Людмил; Stoyanov, Ludmil; Бъндева, Костадинка; Bundeva, Kostadinka; Зарков, Захари Живков; Zarkov, Zahari Zhivkov; Спиров, Димитър; Spirov, Dimitar Date: 2009 Abstract: The paper deals with the squirrel cage induction generator model realization in Matlab/Simulink environment. Some simulations are made to justify the model correct work in different operation modes. Moreover there is shown the experimental and simulation results comparison Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Нови високоефективни изолационни системи за високоволтови електрически машини Author: Сотиров, Димитър Кирилов; Sotirov, Dimitar Kirilov; Ризов, Пламен; Rizov, Plamen; Филипов, Валентин; Filipov, Valentin; Дойчев, Владимир; Doichev, Vladimir; Крачев, Боян; Krachev, Boian Date: 2009 Abstract: The quality of the modern electrical machines is determined by the properties of the used materials: electrotechnical steel, conducting and insulating materials. In high voltage machines insulation occupies significant armature slot space which determines the expenses of active materials and also the machine's overall dimensions, the ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Един подход за решаване на метрологичните проблеми при повишаване на точността на системите за търговско измерване на големи количества електрическа енергия Author: Костадинов, Петко Захариев; Kostadinov, Petko Zahariev; Даскалов, Живко; Daskalov, Jivko; Гунински, Стефчо Георгиев; Guninski, Stefcho Georgiev; Tодорова, Калинка; Todorova, Kalinka Date: 2009 Abstract: Increasing the accuracy of measuring the amount of active and reactive energy in electricity transmission and distribution networks with high and medium voltage is a topical issue for both producers and consumers of electricity energy. As a radical solution to the problem is related to making new slow reimbursing investments for more precise ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Влияние на посоката на относителното движение върху изходния сигнал на трансформаторен електромагнитен преобразувател с отместени намотки Author: Гунински, Стефчо Георгиев; Guninski, Stefcho Georgiev; Иванов, Валери; Ivanov, Valeri Date: 2009 Abstract: The work has investigated the influence of relative speed on the output transformer electromagnetic transducer with displacement square coils with similar dimensions. Series numerical experiments were conducted, the results of which were built direction diagrams and dependencies of the effective value and phase angle of output voltage on ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Изследване на междунавивково късо съединение в трансформатор Author: Тодоров, Георги Димитров; Todorov, George Dimitrov; Благоев, Калин; Blagoev, Kalin; Ганев, Георги; Ganev, Georgi Date: 2009 Abstract: The influence of interturn short circuit in the secondary winding of a transformer on the primary winding’s quantities, that are subject of monitoring, has been investigated. The analysis has been done depending on the short circuit position, number of turns in the short-circuited loop and the supply voltage. An opportunity to detect this ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Мобилна електронна апаратура с микропроцесорно управление за изследвания, тестване и изпитания на акумулаторни батерии Author: Гишин, Стоян Стоицов; Gishin, Stoian Stoitsov; Господинов, Васил Спасов; Gospodinov, Vasil Spasov; Боев, Красимир Иванов; Boev, Krasimir Ivanov Date: 2009 Abstract: The equipment is applicable for accumulator batteries of various electrochemical systems – lead-acid, nickel-cadmium and others, as well as for serviceable and hermetic batteries. The electronic equipment is applicable for stationary, traction and starter accumulator batteries. The electronic equipment has been used in testing and trials ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Методика за изследвания, тестване и изпитания на акумулаторни батерии Author: Гишин, Стоян Стоицов; Gishin, Stoian Stoitsov; Господинов, Васил Спасов; Gospodinov, Vasil Spasov; Боев, Красимир Иванов; Boev, Krasimir Ivanov Date: 2009 Abstract: Methods and software were created for automatic testing and trials of lead-acid, nickel-cadmium and other accumulators and batteries. The major advantages of the methods and software are such that testing is carried out without interrupting the use of the batteries for autonomous electric supply. Using the methods and software installed on ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Експериментално определяне на допустимите граници на изменение на реактивната мощност на хидрогенератори в зависимост от загряването на крайните пакети на статора Author: Сотиров, Димитър Кирилов; Sotirov, Dimitar Kirilov; Михов, Михо Рачев; Mihov, Miho Rachev; Баташки, Стоян; Batashki, Stoyan Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Изследване на влиянието на асиметрично аксиално изместване на полюсите на хидрогенератори върху вибрациите Author: Сотиров, Димитър Кирилов; Sotirov, Dimitar Kirilov; Ризов, Пламен; Rizov, Plamen; Панайотов, Ивайло Димитров; Panayotov, Ivailo Dimitrov Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Моделиране на лабораторни изследвания на трансформатори с използване на MATLAB/SIMULINK Author: Спасов, Радослав; Spasov, Radoslav Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Оптимизиране на огледални оптични системи с отчитане на многократните отражения между лампата и рефлектора Author: Василев, Христо; Vassilev, Hristo; Ангелов, Ангел; Angelov, Angel Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Дифузен светодиоден осветител Author: Василев, Христо; Vasilev, Hristo; Георгиев, Вълчан Тодоров; Gueorgiev, Valchan Todorov; Ганчев, Ганчо; Ganchev, Gancho Date: 2009 Abstract: 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. Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Особености при регулирането на реактивното натоварване на минивец Author: Цонева, Деница; Tsoneva, Denitza; Цолов, Ангел Белчев; Tzolov, Angel Belchev; Крумов, Андрей Христов; Krumov, Andrei Hristov Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Разпределение на реактивното натоварване на синхронни генератори от една електрическа централа при различни принципи на регулиране – математически модел Author: Цонева, Деница; Tsoneva, Denitza; Цолов, Ангел Белчев; Tzolov, Angel Belchev; Крумов, Андрей Христов; Krumov, Andrei Hristov Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Установка за контролируемо разтегляне на открити електрически дъги в контактни мрежи 25kv Author: Ангелов, Иван Колев; Angelov, Ivan Kolev; Матов, Петър Иванов; Matov, Peter Ivanov Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Оценка на ефективността на спектралния състав на светлоизточниците в уличното осветление , Author: Костов, Красимир; Kostov, Krassimir; Василев, Николай Иванов; Vassilev, Nikolay Ivanov; Караро, Улрих; Kararo, Ulrich Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Минимизиране на светлиния поток на улични осветителни уредби за обслужваща, събирателна и главна улица нормирани по видимост Author: Стефанов, Станимир; Stefanov, Stanimir Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Енергийноефективни светлоразпределения от тип «плосък лъч» за събирателни и обслужващи улици , Author: Пачаманов, Ангел Саракинов; Pachamakov, Angel Sarakinov; Христов, Константин; Hristov, Konstantin; Енева, Петя; Eneva, Petia Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Оптимизиране на светлоразпределението на осветители за пешеходни зони Author: Пачаманов, Ангел Саракинов; Pachamanov, Angel Sarakinov; Христов, Константин; Hristov, Konstantin Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA