Recently added

TECHNICAL UNIVERSITY - SOFIA: Recent submissions

Now showing items 161-180 of 899

Title: Изследване сезонните колебания на слънчевата енергия Author: Стоянов, Ивайло; Stoyanov, Ivaylo Date: 2009 Abstract: The result of continuous observations of the monthly solar radiation, on the territory of Ruse University from January 2005 to August 2009, have been presented in this study. The levels of solar energy for the different seasons and months of the year, and their influence on a low power photovoltaic system have been analyzed. Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Управление на инверторно асинхронно електрозадвижване с програмируем логически контролер от фамилията SIMATIC S7-200 НА SIEMENS Author: Павлов, Георги Митков; Pavlov, Georgi Mitkov; Димитров, Васил; Dimitrov, Vasil Date: 2009 Abstract: This paper presents the technical parameters and characteristics of a contemporary microprocessor control with a programmable logic controller (PLC) of the S7-200 series on an inverter asynchronous electrical drive. It is suggested to build a laboratory simulator, which meets the contemporary requirements for the educational and research ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Система за адаптивно управление на улични осветителни уредби Author: Пачаманов, Ангел Саракинов; Pachamanov, Angel Sarakinov; Матанов, Николай Стефанов; Matanov, Nikolai Stefanov; Христов, Константин; Hristov, Konstantin Date: 2009 Abstract: The current paper describes the functions of a control system for adaptive road lighting, developed in the “Electrical Power Supply, Electrical Equipment and Electrical Transport” department of the Technical University of Sofia. The system’s hierarchy consists of power line controllers, mounted in the base of the lighting poles and bridge ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Разработване на унифицирана методика за обучение по обследване енергийната ефективност на асинхронни електрозадвижвания Author: Динолов, Огнян; Dinolov, Ognjan; Андонов, Кондю; Andonov, Kondio; Кръстева, Анка; Krusteva, Anka; Коев, Константин; Koev, Konstantin Date: 2009 Abstract: Based on the constructed automated system a unified training procedure on energy-efficiency investigation in induction motor drives is developed. The procedure and the corresponding learning process, respectively, are organized into six main stages. In order to implement the procedure in the teaching and training of specialists, a computer ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Моделиране на приходите при анализ на проектите с възобновяеми източници на енергия Author: Андонов, Кондю; Andonov, Kondyu; Мартев, Красимир; Martev, Krasimir; Коев, Константин; Koev, Konstantin; Динолов, Огнян; Dinolov, Ognyan; Новакова, Атанаска; Novakova, Atanaska Date: 2009 Abstract: A solar photovoltaic energy park (117 kW) and a wind energy generator (225 kW) are investigated. An assessment and prognostic revenues methodology for sale and trading the harmful emissions of electrical produced energy by render an account of interests, inflation and the cost change of same energy is offers. The purpose of methodology is ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Стенд - симулатор на оперативни превключвания в електрически разпределителни уредби Author: Тодоров, Десислав; Todorov, Desislav; Крумов, Андрей Христов; Krumov, Andrej Hristov; Овчаров, Александър Хубенов; Ovcharov, Alexander Hubenov; Боев, Красимир Иванов; Boev, Krasimir Ivanov; Бакалски, Георги Благов; Bakalski, Georgi Blagov; Апостолов, Атанас; Apostolov, Atanas; Добрев, Добри Михайлов; Dobrev, Dobri Mihaylov; Драгостинов, Стефан; Dragostinov, Stefan; Гъркова, Маргарита; Gurkova, Margarita; Костова, Албена; Kostova, Albena; Вълчев, Емил; Valchev, Emil Date: 2009 Abstract: In „Electric Power Engineering“ Department at the Technical University of Sofia is designed and assembled switchgear installation control, supervision and interlocking simulator. Physical model gives opportunity to simulate operations in all switchgear systems with single and multiple bus bars, with one circuit breaker per bay, and introduce ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Изследване на умокрянето на нискоенергийни повърхности след плазмено-химично окисление Author: Динев, Петър Дончев; Dineff, Peter Donchev; Господинова, Диляна Николаева; Gospodinova, Dilyana Nikolaeva Date: 2009 Abstract: Cold plasma-chemical surface oxidation was applied into changing the hydrophilic-hydrophobic balance of polyester insulating film before and after ethyl alcohol surface cleaning. Two representative atmospheric plasma source were in use – symmetrical dielectric barrier co-planar diode discharge and asymmetrical or hybrid corona-dielectric ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Хомогенен атмосферен бариерен разряд Author: Динев, Петър Дончев; Dineff, Peter Donchev Date: 2009 Abstract: The Townsend quasi-homogeneous breakdown mechanism can be applied not only for low pressure but as well for relatively short air daps (5,26 cm) atatmospheric pressure. The real power surface density characteristic of atmospheric pressure dielectric barrier discharge reveals the existence of avalanche (quasihomogeneous) steady-state mode of ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Йонно-плазмено ецване и функционализиране на поли (диметилсилоксанови) повърхности Author: Динев, Петър Дончев; Dineff, Peter Donchev; Владкова, Тодорка; Vladkova, Todorka; Господинова, Диляна Николаева; Gospodinova, Dilyana Nikolaeva; Керанов, Иван; Keranov, Ivan Date: 2009 Abstract: Modification of polymer surfaces by changing the chemical structure, surface energy, and bonding characteristics has considerable technological importance in the area of biocompatibility. Interest has been increasingly in recent years directed to plasma oxidized poly(dimethylsiloxane) surfaces as bioactive substrate having a capacity to ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Еднофазен инвертор за възобновяеми източници на енергия, свързан с мрежата Author: Лазаров, Владимир Димитров; Lazarov, Vladimir Dimitrov; Зарков, Захари Живков; Zarkov, Zahari Zhivkov; Кънчев, Християн; Kanchev, Hristiyan Date: 2009 Abstract: This paper is devoted to the study of a single-phase inverter for connection of generator using renewable energy sources (RES) to the utility grid. A computer model of the inverter is developed. The model allows inverter operation with variable in the time input power. Thus the inverter can be easily connected to a DCDC converter with maximum ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Управлението на енергийните потоци в хибридна система с възобновяеми източници на енергия Author: Франсоа, Брюно; François, Bruno; Лазаров, Владимир Димитров; Lazarov, Vladimir Dimitrov; Нотон, Жил; Notton, Gilles; Стоянов, Людмил; Stoyanov, Lyudmil; Зарков, Захари Живков; Zarkov, Zahari Zhivkov; Кънчев, Християн; Kanchev, Hristiyan Date: 2009 Abstract: Taking intо account the variable primary sources character in the hybrid system of renewable energy sources and the consumers, powered by this system (some of them need a constant power source), the need of a power management in a hybrid system emerges. This article reviews the researches in the hybrid systems domain. Also the importance ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Моделиране и симулиране на синхронен генератор Author: Лазаров, Владимир Димитров; Lazarov, Vladimir Dimitrov; Спиров, Димитър; Spirov, Dimitar; Зарков, Захари Живков; Zarkov, Zahari Zhivkov; Стоянов, Людмил; Stoyanov, Ludmil Date: 2009 Abstract: This paper examines the process of modeling and simulation of synchronous generator with exciter and damper winding in the programming environment of Matlab/Simulink for use in complex wind energy conversion systems simulations. The aim is realized in the following stages: mathematical modeling, program integration and series of model ... Library:
TECHNICAL UNIVERSITY - SOFIA
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