Simulation of modular current-source converter

Tato práce se zabývá problematikou proudového modulárního měniče a jeho využitelnosti v HVDC systémech. Teoretická část se věnuje obecnému popisu proudového modulárního měniče, kde je využito topologické analogie s modulárním měničem napěťového typu, a možnostem jeho řízení jako tradičního víceúrovňového měniče. Praktická část je věnována tvorbě simulačních modelů proudového modulárního měniče a jeho částí pro ověření teoretických předpokladů a použitelnosti aplikovaných typů řízení. Tato část navíc obsahuje kapitolu ověřující teoretické předpoklady experimentálním měřením na sestaveném laboratorním prototypu.ObhájenoThis thesis deals with problematic of current-source modular multilevel converter and its possibility to be used in HVDC systems. In the theoretical part, the basic proposal of current source MMC based on topological analogy with voltage source MMC is described and the usability of traditional voltage source MMC modulation techniques is discussed. The practical part deals with the simulation models of current-source modular multilevel converter and its parts in order to confirm the theoretical supposal and the applied modulation methods suitability. Moreover, there is a chapter confirming the theoretical supposal by measurement after constructing one half-bridge-cell phase of the converter in this part of thesis

Impact of demographic changes on municipal technical infrastructure in the Czech Republic - case study of waste management

Impact of demographic changes on municipal technical infrastructure in the Czech Republic - case study of waste management Abstract The aim of this study is to quantify the impact of demographic development on the current household production of municipal waste in the Czech Republic and at the same time to compare their influence with the impact of other factors. Based on a literature review and statistical data available for the Czech Republic, a set of 22 explanatory variables concerning structure of population by age, gender, highest education and employment, as well as the size of households, unemployment, purchasing power, population density and basic characteristics of housing was identified in order to explain the production of municipal solid waste, mixed municipal waste and separately collected waste components (glass and plastics). It has turned out that demographic variables, especially the average household size, gender, age, level of education or sector of employment have a statistically significant but rather weak impact on the production of these waste streams. Given that the detailed analysis of the variables indicated that there is a significant spatial variability of these characteristics and that they exhibit spatial non- stationarity, the next step was to analyze the relationship of the..

Simulation models of buck converters

Tato práce se zabývá popisem a návrhem simulačních modelů pulzních měničů. Simulace byly realizovány v prostředí Matlab/Simulink s pomocí knihovny PLECS, která obsahuje speciální prvky pro simulaci problémů z oboru elektrických pohonů a výkonové elektroniky. Modely byly navrženy tak, aby byly snadno použitelné a rozšiřitelné ve výuce vybraných předmětů na katedře elektromechaniky a výkonové elektroniky. V teoretické části jsou představeny jednotlivé typy pulzních měničů a popsáno prostředí, ve kterém byly tvořeny simulace, tedy Matlab, Simulink a PLECS. Část praktická se pak věnuje samotným simulačním modelům, sledován je zejména vliv změny různých parametrů na průběh napětí a proudu.Katedra elektromechaniky a výkonové elektronikyObhájenoThis thesis deals with proposal and design of buck converters simulation models. Simulations are designed in Matlab/Simulink environment with PLECS additional toolbox which contains special tools for simulations focused on electric drives and power electronics. Models were designed in the way to be easily used in selected courses at the Department of electromechanical systems and power electronics. In the theoretical part, several types of buck converters are presented and the development environment is described, which the simulations are created (Matlab, Simulink, PLECS) in. The practical part deals with the designed simulation models, particularly the influence of change of selected circuit parameters on current and voltage profile is observed

Impact of demographic changes on healthcare expenditures in the Czech Republic

Impact of demographic changes on healthcare expenditures in the Czech Republic Abstract This work aims to analyse the influence of demographic changes on public healthcare expenditures in the Czech Republic. The first part displays particular factors having effect on healthcare expenditures with a special focus on demographic characteristics. In spite of the fact that the expenditure level seems to be mainly affected by the economic output of particular states and new technology development, while the influence of demographic fluctuation is of minor effect so far, this situation is likely to change. The next part presents the health care expenditures evolution in the Czech Republic from the beginning of the nineties. The data sources confirm that these expenditures keep growing just the same way as in other states in the world. The last part defines and quantifies the foreseen scenarios of the above mentioned health care expenditures depending upon demographic evolution. The results of those scenarios are being compared with other analysis results focusing on analyzing the influence of ageing process and health condition fluctuations on expenditure levels in the Czech Republic as well as in other EU countries. Keywords: population ageing, health care, costs of dying, health, new technologies, healthcare..

The accruing obesity as a pronounced causative factor of the prospective progression of mortality

Katedra demografie a geodemografieDepartment of Demography and GeodemographyPřírodovědecká fakultaFaculty of Scienc