National Repository of Grey Literature 40 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Simulation of steady-state and dynamic behavior of low-temperature fuel cell
Smugala, Ondrej ; Radil, Lukáš (referee) ; Ptáček, Michal (advisor)
This bachelor´s thesis is concerned with mathematic modelling of low temperature proton exchange membrane fuel cell (PEMFC). First part of the thesis is focused on explaining the principle of production of electricity by this type of source. The main advantages and disadvantages of this technology are presented there. A division of fuel cells according to the stack temperature and the kind of used electrolyte is also made in this part. Typical technical information is mentioned for every type of fuel cell. The rest of thesis is concerned with the PEMFC. Firstly there is a description of construction of fuel cell and a presentation of applications in the industry. The second part of work includes a mathematical description of steady and dynamic behavior of fuel cell which is based on relations among fundamental parameters and quantities. The other part contains all results of simulation which was made on a model created in Matlab Simulink. Comparison of the results of real measurement with the results of simulation which was performed on a modified model is provided in the last part of thesis.
Performance Analysis of IBM POWER8 Processors
Jelen, Jakub ; Kešner, Filip (referee) ; Jaroš, Jiří (advisor)
This paper describes the IBM Power8 system in comparison to the Intel Xeon processors, widely used in today’s solutions. The performance is not evaluated only on the whole system level but also on the level of threads, cores and a memory. Different metrics are demonstrated on typical optimized algorithms. The benchmarked Power8 processor provides extremely fast memory providing sustainable bandwidth up to 145 GB/s between main memory and processor, which Intel is unable to compete. Computation power is comparable (Matrix multiplication) or worse (N-body simulation, division, more complex algorithms) in comparison with current Intel Haswell-EP. The IBM Power8 is able to compete Intel processors these days and it will be interesting to observe the future generation of Power9 and its performance in comparison to current and future Intel processors.
Steady state and short-circuit conditions within E.ON 110kV power network at bridge operation of transformers T401 and T402 in 400/100kV transformer station Čebín
Klobučník, Jozef ; Janda, Petr (referee) ; Blažek, Vladimír (advisor)
Master’s thesis deals with computation of steady state and short-circuit conditions in the 110 kV distribution network in the nodal area of Čebín. Computations are done during independent operation and bridge operation of transformers T401, T402 in transformation station Čebín with proposed configuration of network. Additional computations of steady state during specific operating conditions such as (T401 outage, disconnection of line 5553) were done during network operation in bridge operation of T401, T402. Voltage conditions in substations, load of 110kV lines and 400/110 kV, 110/HV kV transformers are evaluated based on the computations of steady state. Short-circuit resistance of substations is being evaluated with the aid of calculations of short-circuit conditions. There is a comparison and processed results of computations during independent operation, bridge operation, special operational states and proposed technical measures of operation in bridge operation in the end of the thesis. Theoretical part of the master’s thesis deals with the description of 110 kV distribution networks, theory of calculation of the steady state of electric system with the aid of Newton iterative method a calculation of single-phase and three-phase short-circuit current with the aid of method of symmetrical components.
Proposal of the reconstruction of a distribution network in a specific area
Richter, Miroslav ; Mrvová, Dana (referee) ; Blažek, Vladimír (advisor)
The dissertation describes several types of low and high voltage distribution networks including their implementation in specified location with regards to the reliability and quality of electric power supply. The distributions networks are classified according to ways of cable routing, distribution line voltage levels as well as according to types of network interconnections. The high and low voltage distribution networks are further categorized based on used cable types, where, more attention is paid to insulated lines used in the Czech Republic, low voltage lines called „AES“ and „PAS“ high voltage lines used more and more during the distribution network reconstruction. Attention is also given to the description of used methodology for the calculation of network performance stability. An individual part of the dissertation is devoted to a low voltage distribution network proposal in the village of Kovalovice. Based on performed analysis of distribution network conditions, several reconstruction versions were proposed with the help of „KASI“ software, the description of which is also included. The proposed versions are further analysed for both, technical and economical aspects and is selected most suitable version of the distribution network.
Steady state and short-circuit conditions in 110kV E.ON network fed from Sokolnice transformer station
Vyčítal, Václav ; Rampl, Martin (referee) ; Blažek, Vladimír (advisor)
This thesis can be divided into five main parts. The first part deals with theoretical analysis of power flow calculation in power network during steady state condition. Load flow calculation is presented here as a linear and nonlinear problem. Newton iteration method is proposed for solving power flow as nonlinear problem. The second part of this thesis deals with the analysis of short-circuit calculation in accordance with valid International Standard IEC 60909. The equivalent voltage source method is adopted in case of the short-circuit calculation. For the calculation of unbalanced short-circuit currents, the symmetrical components method is also presented. The last three parts of this paper are focused on calculations of power flow and short-circuit conditions in power grid Sokolnice. So in the third part is the description of nodal area Sokolnice with its substations and the calculation of load flow and short-circuit conditions for two different power supply options. For each supply option is also considered an abnormal (fault) grid condition. (overall there are solved four different options) The fourth part of this thesis deals with the result analysis and also the results of different power supply options are compared. In the last part there are presented necessary technical improvements for fault-free operation of power grid Sokolnice based on the result of power flow and short-circuit conditions in that grid.
Optimized Thermo-dynamic Senzor with Balance P¨rincip
Řezníček, Michal ; Jankovský, Jaroslav (referee) ; Szendiuch, Ivan (advisor)
This work deal with taking advatage of ballance thermodynamic sensors as the replacement of commercial temperature sensors.
Load Flow Calculation and Design of Distance Protection Relay Settings of 110 kV Overhead Line
Jasenský, Filip ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
Bachelor thesis load flow calculation and design of distance protection relay settings of 110 kV overhead line acquaints with the theory calculation of steady operation, short-circuit conditions and a proposal setting the distance protection. The theoretical part is made an example of a simple calculation to show leadership methods of calculation. The practical part is a calculation of steady operation and short-circuit conditions. Short-circuit ratios are calculated for a single operation and parallel operation of transformers in Otrokovice. Calculated using the initial shock symmetrical output from the calculation of short-circuit conditions is verified by short circuit resistance of substations. The practical section setting the distance protection ABB REL 316*4 and compensation earth faults. Calculation of steady state and short-circuit conditions designed basic operational state of the network, for which the design of a distance protection relay settings.
The analysis of parallel operation variants of supply areas 110 kV Čebín and Sokolnice
Reiter, Martin ; Vaculík, Petr (referee) ; Toman, Petr (advisor)
The diploma thesis is focused on the analysis of parallel operation of Čebín and Sokolnice substations. Different variants of parallel operation are researched. A calculation of steady state by the iterative method is described in the theoretical part. The next part briefly mentions a short-circuit and dimensioning of conductors. The possibility of overloading of lines and transformers is discussed in the last chapter of the theoretical part. The current state of the situation is described in the practical part. Main goal of the practical part of the diploma thesis is to design a configuration capable to parallel operation. Also another configuration of supply of this area is designed. There must be no direct connection between Čebín and Sokolnice substations on 110kV level in this configuration. This configuration should eliminate a transit flow of power. Each configuration has to fulfill the requirements on the steady state and on short-circuit current capability. One of the last chapters is focused on the steps, that should by undertaken to prevent transit flow of power.
Evaluation of possibilities for connection of wind farm Drahany 45 MW to 110 kV network
Gregr, Tomáš ; Opat, Jaroslav (referee) ; Topolánek, David (advisor)
This Master's thesis is focused on connecting of new power sources into electrical network, particularly, the steady state and allowed voltage variation in network nodes, which occur in steady state before and after connection of a new power source into distribution network, with regard to valid legislation. The new power source in question is the new wind farm Drahany with active power of 45 MW, which should be connected into distribution network 110kV, operated by distribution company E.ON. The aim of this work is to find the most suitable connection point of a wind farm into distribution network, considering transmission capacity of individual electric lines and voltage variations in network nodes, as well as Drahany wind farm's investor's expenses on construction of a connection line to connection point and the distribution network's operator's expenses on modification of the connection point. Also, methods of calculating of electric networks in steady state are described in this paper, particularly, linear calculations, because these are needed for the calculations in E-vlivy program, in which the possible options of Drahany wind farm's connection into network 110 kV, in various places, were modeled. The description of the E-Vlivy program is also included in this paper. The E.ON company's materials form the basis for this Master's thesis, which will later serve as one of the documents needed for Drahany wind farm’s connection point evaluation into distribution network 110 kV.
Steady state and short-circuit conditions within E.ON 110 kV power network at parallel operation of nodal areas of Otrokovice substation and Sokolnice substation
Mikulinec, René ; Janda, Petr (referee) ; Blažek, Vladimír (advisor)
This thesis deals with the steady operation and short-circuit conditions in the 110 kV network E.ON in a separate and parallel operation of nodal areas of Otrokovice substation and Sokolnice substation. The theoretical part is devoted to the calculation of steady state high-voltage systems using Newton's iterative method, transient phenomena that may occur in the power system short-circuit calculations and theories. The practical part deals with the actual calculations of steady state and short-circuit conditions in a separate and parallel operation of nodal areas Sokolnice-Otrokovice, which were calculated using the dispatching program. These calculations are then evaluated for possible use of involvement in actual operation. At the end there are suggestions on operational measures in the network 110 kV.

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