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This article deals with the methods for analysis of component wear in cars. From a variety of electrical and non-electrical components, suitable elements have been selected to determine the mechanical wear of the whole car. As main component, the knock sensor has been selected, whose task is to achieve the most efficient combustion of a mixture of gasoline and air. Evaluation circuit adjusts this...
The article deals with the control of the light level of four-colour RGBA LEDs for illumination of samples of a microscope while the methods of control of the light level are introduced and discussed first. In the next part of the article, four LED drivers for four-colour LEDs are selected. The calculation of a circuit elements of the LED driver and the calculation the peripheral elements of the control...
In the balance section Electricity supply, the output quantities are electrical energy and heat generated in heat plants and in combined heat and power plants whereas the input quantities are primary and secondary energy carriers. In the recent years, new sources of primary energy, mostly renewable, appeared next to traditional fuels. In the modelling of energy transformation, energy carriers are...
The paper presents a method for detecting non-linear high resistance earth faults in compensated medium voltage networks, based on the criterion of reactive power of higher harmonics of zero sequence current and voltage. Harmonics content of currents and voltages as the function of network parameters and nonlinear fault resistance was estimated. The model of earth fault protection using that criterion...
In this paper is discussed and evaluated the using of various concept of traction drives in Czech Republic and in the World. The article is focused on application of innovative solutions especially high speed traction drives with permanent magnet synchronous machines. In the research is evaluated the impact of high speed application and assessed the advantages and disadvantages of the new concept...
This paper presents the analytical thermal analysis of a permanent magnet generator stator coil. The analytical analysis consists of a lump parameter thermal network (LPTN) to predict the steady state and transient temperature of the coil module. In the steady state part the average temperature of different parts of the network are estimated by using the matrix inversion and an iterative loop. In...
In this work a study is carried out to improve the water pumping system, to be used to improve the electrical efficiency of photovoltaic panels by reducing the operating temperature of the modules. The methodology used modifications in the geometric height of the system and different types of pumping systems, with constant speed and variable speed using a frequency inverter. Through these changes...
Electric drainage is used to protect devices which are buried underground (such as piping) from the negative effects of DC electric traction induced stray currents. In places where stray currents leave the underground device and return into rails, they contribute to the corrosion of buried devices. Electric drainage is one of the possibilities to minimise these negative effects. Electric drainage...
Choice of materials is one of the most important steps during the development and design of electrical switching devices. Sufficient electrical and thermal conductivity, mechanical strength and environmental stability are the most important material properties for current conducting path. Contact area is the most critical part of the entire current-path. Nowadays, DC switching devices are more and...
This reason to carry out this investigation was a complaint from international airport about increased maintenance cost and insufficient reliability of runway lighting systems. The exhaustive investigation of overall lighting installation was carried out, which comprises lighting parameters, mechanical parameters and electrical parameters. The possible causes of luminous flux drop and significantly...
This paper deals with the methodology of software to promote optimised operation of the transmission network. The methodology is based on the real data referring to operating temperatures and the power transmitted over 220 kV and 400 kV lines. This is an input database, formed by the values of power transmitted at a real time temperature. The software designed here offers a choice of the line to be...
The change of operating conditions by circuit breaker switchings or initiation of emergency conditions (short circuits) is accompanied with transient processes. The physical nature of a transient process is redistribution of the stored energy between inductive and capacitive network elements. In some cases, circuit breaker opening may induce high-frequency overvoltages, while circuit breaker closing...
Progressive processing method which uses microwave assisted gasification of selected types of waste is discussed in this work. A brief summary of waste management in the EU and processing capabilities are given in the introduction. The next section discusses the legislative aspects of waste management. Substantial part presents the research results achieved when microwave assisted gasification was...
The paper presents an innovative concept of the new area measuring algorithm and new area decision algorithm for power lines' distance protection. These algorithms improve the operating conditions of the distance protection. The primary purpose of the new measuring algorithm is correct the short-circuit impedance calculation. The purpose of the new decision algorithm is correct identify of the line...
Transmission expansion planning requires static and dynamic analyses. Planning criteria include the selection of contingencies consisting of faults and their clearing, performance standards, transmission system adjustments, and corrective action plan. Performance standards relating to power system dynamics mainly concern the voltage ride through and transient angle stability i.e. retaining synchronism...
Energy crisis around the world and implementation of so-called Package 3×20 where one of its demands aimed at increasing the share of renewable energy sources in overall balance, result in a significant increase in the interest in geothermal energy, and thus in the production of electricity from geothermal sources. Unfortunately, in Poland and the Czech Republic we are dealing mainly with low and...
This work is focused on diversity analysis of daily load curves and outlier curve detection in distribution networks. For diversity evaluation unified load curves are defined and the Euclidean distance between them and the average curve is calculated. Outlier detection is based on the distance between a load curve and an average curve representing curves of the same day of the week as the analyzed...
Trend of increasing the share of electricity production from the renewable energy sources will surely continue the in the upcoming time period. This paper outlines multiple solutions of accumulation of energy, especially electricity, in the Technology Center of Ostrava (TCO). It presents solutions for storage of electrical energy into the batteries with use of power converters with an additional function...
This paper deals with problems which occurs in low voltage grid in case of high renewable energy penetration, especially with photovoltaic power plants. Also simple way how to utilize energy storage to address these problems is proposed and simple charge/discharge strategy was designed for energy time shifting and capacity firming. Simulation model in Matlab Simulink was developed and two scenarios...
Voltage fluctuations in the distribution network affect the fluctuation of the luminous flux of light sources which are fed by this network. This phenomenon is quantified in standard ČSN EN 61000-4-15 which defines the method of measuring and evaluating the so-called flicker (flicker factor). This parameter can have a very negative effect on human comfort or even health. In the above standard, the...
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