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

Now showing items 181-200 of 853

Title: Компютърно симулиране на разпространението на високочестотни сигнали в силови кабели за средно напрежение Author: Червенкова, Тодорка Вълева; Chervenkova, Todorka Valeva; Червенков, Атанас Георгиев; Chervenkov, Atanas Georgiev; Божков, Стоян Х.; Bozhkov, Stoyan H. Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Определяне на механичните загуби на синхронна машина по метода на самоспиране Author: Михов, Михо Рачев; Mihov, Miho Rachev; Сотиров, Димитър Кирилов; Sotirov, Dimitar Kirilov; Баташки, Стоян; Batashki, Stojan Date: 2009 Abstract: 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. Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Заместваща схема на синхронна машина и еквивалентност на основните формули Author: Божилов, Ганчо Йорданов; Bojilov, Gantcho Yordanov Date: 2009 Abstract: 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) ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Към определянето на ефективната стойност на тока на еднофазните колекторни двигатели с наситена магнитна система, Author: Божилов, Ганчо Йорданов; Bojilov, Gantcho Yordanov; Иванов, Адриан Петров; Ivanov, Adrian Petrov Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Моделни изследвания за определяне характеристиките н въглищни потоци от складовото стопанство на ТЕЦ „Марица Изток 3” Author: Бонев, Бончо И.; Bonev, Boncho I. Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Определяне качеството на въглищата на изхода от рудник в енергийния комплекс „Марица Изток” Author: Бонев, Бончо И.; Bonev, Boncho I. Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Методи за научни визуализации – част 2 Author: Георгиев, Веселин; Gueorguiev, Vesselin; Георгиева, Десислава В.; Georgieva, Desislava V. Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Методи за научни визуализации – част 1 Author: Георгиев, Веселин; Gueorguiev, Vesselin; Георгиева, Десислава В.; Georgieva, Desislava V. Date: 2009 Abstract: 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 ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Относно едно диференциално уравнение от дробен ред с непостоянни коефициенти Author: Николова, Янка Великова; Nikolova, Yanka Velikova Date: 2009 Abstract: This paper refers to the solution of a two-terms fractional differential equation with nonconstant coefficients. A transform method is applied and a generalized Laplace-type integral transform is used. The explicit solution obtained agrees with previously established result by T. Nonnenmacher related to a special class of normalized one-sided ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Измерване и моделиране на статорната индуктивност на превключваем реактивен двигател 12-8 с помощта на изкуствени невронни Author: Динчев, Димитър; Dinchev, Dimitar; Velinov, Valeri; Галинов, Иво; Galinov, Ivo; Горбунов, Ясен Владимиров; Gorbounov, Yassen Vladimirov; Павлитов, Константин Недялков; Pavlitov, Konstantin Nedyalkov Date: 2009 Abstract: The growing popularity of the Switched Reluctance Motors (SRM) during the last years is due to the extensive development of the power electronics and the vast opportunities of computer control and simulation systems application. In this article an innovative method has been suggested. It is used for a nonlinear identification of the stator ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Използване на клъстерен анализ за определяне влиянието на основни параметри на лазерите с пари на меден бромид върху коефициента им на полезно действие Author: Денев, Николай; Denev, Nikolay Date: 2009 Abstract: A copper bromide vapor laser of wavelengths 510.6 nm and 578.2 nm is the object of this research. The aim of the work is the investigation of relative influence of the basic laser parameters just like input power, geometric dimensions, hydrogen gas pressure etc. on laser efficiency. A big quantity of experimental data is used from the Metal ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Отражение на обектива на термовизионната камера при наблюдение на близки обектив Author: Видеков, Валентин Христов; Videkov, Valentin Hristov; Андонова, Анна Владова; Andonova, Anna Vladova Date: 2009 Abstract: This paper presents the results from the investigation related to the influence of the close position of a thermo vision camera when studying micro objects. This kind of camera is used to determine the temperature distribution of objects in operation mode. The results from the impact of the camera lens on the pads with high coefficient of ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Вариант на твърдотелно анизотропно контактуване Author: Видеков, Валентин Христов; Videkov, Valentin Hristov; Цанева, Боряна Рангелова; Tzaneva, Boryana Rangelova; Бояджиев, Стефан Иванов; Boyadjiev, Stefan Ivanov; Ячовски, Александър; Yachoski, Alexander Date: 2009 Abstract: This paper presents an alternative method for contacting and connection between electronic components. An anisotropic conducting plate is suggested to be used Instead of the well-know anisotropic adhesives. The construction of such a plate and its basic parameters are presented. A technological version for preparation based on nanopore anode ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: E-learning with MOODLE in the energetics and electronics college Author: Spasova, Nadezhda; Спасова, Надежда Date: 2008 Abstract: The aim of the current research is to share experience of the choice and introduction of an e-learning system in the Energetic and Electronics College, as well as considering features of the education - all curriculums are organized to have close relation between theory and practice. A choice of LMS is been made – platform Moodle. Moodle ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Applications of hardware description languages for frequency domain modeling and analysis of analog circuits Author: Panayotov, Ivan Jelev; Панайотов, Иван Желев Date: 2008 Abstract: In this paper the way of using universal Analog and Mixed Signal (AMS) Hardware Description Languages (HDLs) to model and simulate frequency dependant elements such as filters is discussed. Analog description languages such as VHDL-AMS and Verilog-AMS gain popularity as instruments for mixed signals modeling and simulations. They make it ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Development and analysis of a signal transfer circuit with hydrogen bonding Author: Rusev, Rostislav Pavlov; Русев, Ростислав Павлов; Angelov, George; Ангелов, Георги; Atanasov, Boris; Атанасов, Борис; Takov, Tihomir Borisov; Таков, Тихомир Борисов; Hristov, Marin Hristov; Христов, Марин Христов Date: 2008 Abstract: A microelectronic circuit based on hydrogen bonds is developed and analyzed. The simulations in Matlab demonstrate that the biocircuit object emulates the functionality of conventional electrical circuits. The static analysis shows the circuit is akin to current source while the dynamic analysis demonstrates that the circuit successfully ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Microelectronic networks analogous to protein hydrogen bonded networks made from backbone peptides and water molecules Author: Rusev, Rostislav Pavlov; Русев, Ростислав Павлов; Atanasov, Boris; Атанасов, Борис; Takov, Tihomir Borisov; Таков, Тихомир Борисов; Hristov, Marin Hristov; Христов, Марин Христов Date: 2008 Abstract: For microelectronic purposes, signal transfer (proton transfer) in a hydrogen bonding network is studied. The network is extracted from β-lactamase and it includes atoms from protein backbone and water molecules. The model of proton transfer in hydrogen bonds is developed on the basis of Marcus theory and the protein electrostatic theory. ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Possibilities of improvement of monitoring and diagnostic process of power electronic devices Author: Veselinov, Vladislav Danchev; Веселинов, Владислав Данчев Date: 2008 Abstract: In the present article are analyzed the possible break-down situations in the internal electric circuits of power rectifier convertors. The main task is a theoretical report of the developing processes during the occurance of internal short circuits under a failure of one or several valves and their influence upon the rest of them. The ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Inductors influence over the DC-DC converter performance Author: Brusev, Tihomir Sashev; Брусев, Тихомир Сашев; Goranov, Peter Trifonov; Горанов, Петър Трифонов Date: 2008 Abstract: This paper concerns the technological limitation of fully monolithic dcdc converters. Two types of circuits were investigated on AMS CMOS 0.35 µm process. Comparison between efficiency results of architectures used on-chip and offchip filter’s inductors are made. The inductors influence over the dc-dc converters performance is evaluated. ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Interface characterization of PPV – derivative based structures by direct current electrical measurements Author: Aleksandrova, Mariya; Александрова, Мария; Dobrikov, Georgi Hristov; Добриков, Георги Христов; Jivkov, Ivaylo; Живков, Ивайло; Dimov, Deyan; Димов, Деян; Rassovska, Milka Markova; Ръсовска, Милка Малкова Date: 2008 Abstract: Polyphenylenevinylene derivative (PPV – D) based structures with Ohmic and Schottky electrodes have been produced and investigated by direct current– voltage (I-V) measurements. Polymer solutions with different solvent concentrations are prepared and dependence of the film thickness on the amount of solvent is established. It was found that ... Library:
TECHNICAL UNIVERSITY - SOFIA