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AC current sensors
Hašpica, Štěpán ; Huták, Petr (referee) ; Patočka, Miroslav (advisor)
Aim of the bachelor's thesis is to anylize chosen types of AC current sensors with focus on design of one chosen type. Sensoring of AC current can be done for instance by current measuring transformator, Hall's sond or Rogowski coil. These ways and types of sensors are disscussed in chapter no. 2. But main focus of thesis is in finding one definite algorithm for current meassuring transformator. New possible way in design is in-depth disscussed in chapter no. 3. Current meassuring transformator, or other types of sensors finds great application in area of power energetics and electronic engineering.
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Current sensor with digitized output signal
Hanuš, Ivan ; Vágner, Martin (referee) ; Havránek, Zdeněk (advisor)
The objective of this thesis is to describe principles of measuring of alternating current in low voltage power supply network with Rogowski coil and to study details of requirements for electronic current sensor with digital output. Furthermore to study the current solution of digitalization of output signal from Rogowski coil and to determine metrological characteristics of the digitalization module for processing the signal from the Rogowski coil as current sensor and to design a concept of an electronic current sensor unit with Rogowski coil and the digitalization module with the expected optical output. The theoretical part deals with the measurement of current using Rogowski coil, its characteristics and advantages compared to conventional current transformers. Further in the thesis there are specified the requirements for current sensor. The practical part deals with the design of digitalization module consisting of a pair of AD converters, a microcontroller and output circuits. Furthermore, the thesis deals with digital signal processing of signal from Rogowski coil. Furthermore, the thesis describes firmware for microcontroller and PC application. The result of thesis is functional circuit of electronic current sensor that processes signal from Rogowski coil and converts it to digital form.
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Current transducer's characteristics
Čížek, Ondřej ; Bulín, Tomáš (referee) ; Huzlík, Rostislav (advisor)
In this bachelor thesis are described all used current transducers, the way of their function and at each of them are described their properties. After that is described program LabVIEW and measurement, which happened by using it with specialization on frequency characteristics and their evaluation.
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Measurement system for pulsed current source
Myška, Radek ; Križan, René (referee) ; Drexler, Petr (advisor)
This work deals with the description and analysis of suitable methods for measurement of non-periodical high-level current pulses. For pulsed current source design and development a suitable measurement system is required. In this work shunt resistor, Rogowski sensor and magneto-optic sensor are presented. The analysis of their properties is performed in order to design a suitable sensor for test current pulse measurement. A design of Rogowski coil sensor has been made. An experimental measurement of current pulses with short time relations has been performed. The suitability of the coil sensor for non-harmonic waveforms measurement has been evaluated on the basis of measurement results. In case of the magneto-optic sensor a concept utilizing an optical fiber has been proposed. The design of the sensor has been performed also. Individual parts of the sensor were verified. Experimental magneto-optic sensors have been built and their properties have been studied.
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Methods of single impulse detection
Juřík, Vladimír ; Bartušek, Karel (referee) ; Fiala, Pavel (advisor)
This thesis deals with measurement method pulsed quantities of electromagnetic field. This thesis was focused on methods, which make use of optic effect. Specially Faraday effect, Pockels effect and magneto-optic Kerr effect. Next it was focused on method makes use of Rogowski coil. At the end was shortly noticed about method makes use of calorimetric sensor. For experimentally realized has been chosen Faraday Magneto-optic Effect. In optic laboratory has been realized absolute methods and different methods making use of Wollaston polarizer on pneumatic optical desk. The main advantage of this method is the capability to measure the high frequency and high current signals. Next in this thesis has been written theory about Rogowski coil. This method has been experimentally realized in laboratory.
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Comparison of Instrument Transformer and Sensor Applications in Feeder Terminal REF 542plus
Hrycík, Tomáš ; Majer, Karol (referee) ; Orságová, Jaroslava (advisor)
The aim of this Master´s thesis is use of instrument transformers and sensors on field of industry protection. We will compare current and voltage transformers, current sensor – based on Rogowski coil, voltage sensor – based on voltage divider. By this measure devices, we can monitoring values of analog quantities in medium voltage switchgear. It is impossible to compare, measure and analyze without this measure devices. There is protection terminal REF542plus, which can compile this values. The REF542plus ability are measuring, monitoring, remote control and protection. First, we will discuss about theory of sensors and convential instrument transformers and analysis of analog signal. We will compare analog input channel on sensor´s analog module and transformer´s analog module. There are few differences between type of analog modules. For analog signal analysis are important frequency filters and Analog/ Digital Convertor (sigma-delta). We will describe functions and options of REF542plus. In practical part of this project, we will test protection functions of protection terminal. First, protection terminal will be connected to sensors. Second protection terminal will be connected to transformers. For testing we chose Earth-fault directional protection and differential protection. We will make only secondary tests. That´s mean, input analog quantities to REF542plus will be simulated by tester. In all we will verify quality of protection. We will focus on lower settings of protection and we will inject protection by low current. Objectives are testing of trip characteristics and measuring of trip time.
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Design digital optical output
Kubáč, Stanislav ; Beneš, Petr (referee) ; Klusáček, Stanislav (advisor)
This work descibes general principles of measuring the alternating current and voltage using conventional and unconventional sensors.This work shows specific parmeters conected with principles of the measurement, advantages and disadvantages of individual measuring procedures, types of output signals, precisions, limitations, ways of power and so on. Part of the work is to find optimal measurement procedure, which can be aplicated to practical measuring of alternating currents and voltage. Main part of the work concerns the realisation of optimal method of measuring alternating current.
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Current Transformers and Current Sensors Confrontation
Popek, Jiří ; Bok, Jaromír (referee) ; Topolánek, David (advisor)
Current transformers and current sensors are devices which are mostly used for current measurement in high voltage systems. This devices transform measured currents to range which are workable for measurement and protection devices. Current transformers have been using for current measurement since electric system was built. Current sensors are using for measurement after applying digital devices in their secondary circuits. Theoretical part includes fourth and fifth chapter. These chapters contain construction analysis and characteristic points for both devices. Practical part is in chapter six. This chapter consists results from laboratory measurement. Results are used for verification with theoretical part of the thesis. Accuracy class in nominal range and progress for measurement error in overcurrent range was verified for tested devices. Conclusion of this thesis comparing properties and summarises results from laboratory measurement.
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Laboratory test equipment for IGBT transistors
Chvátlina, Pavel ; Vorel, Pavel (referee) ; Patočka, Miroslav (advisor)
This master’s thesis describes the function and realization of the laboratory test equipment designed for measuring and analysing of collector current iC and voltage uCE courses during the opening and closing process of a power IGBT transistor. The opening and closing times toff and ton of the new power transistor IGBT are changing in the range from tenths to the ones s, so the reading of current iC and voltage uCE proceeds in a very short time. The measuring circuit of this test equipment is based on a short-time discharging of a condenser battery to the inductive load over the measured transistor. Consequently it is possible to replace the power supply whose maximum output power would otherwise have to be in the range of ones MW. In the final part of this thesis there are described properties and design of a high-frequency sensor with the Rogowski coil, which can be used for reading collector current course during opening and closing time of the measured transistor IGBT. Collector current iC and voltage uCE courses can be analysed with a storage oscilloscope.
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Application of Sensors and Digitalization Based on IEC 61850 in Medium Voltage Networks and Switchgears
Štefanka, Martin ; Braciník, Peter (referee) ; Müller,, Zdeněk (referee) ; Toman, Petr (advisor)
Vzduchem izolované vysokonapěťové rozváděče jsou nedílnou součástí energetického distribučního řetězce a to jak v průmyslovém, tak ve veřejném sektoru. Hlavní funkcí rozváděče je ochrana pracovního personálu, rozpojování/odpojování a spínání, izolování, měření proudů a napětí, chránění a ovládání zatížení a komunikace dat do řídících systémů. V každé z výše zmíněných funkcí probíhal technologický vývoj v průběhu posledních 40 let. Dnešní rozváděče jsou spolehlivé a elektrickému oblouku odolné zařízení, zoptimalizované téměř k fyzikálním limitům dielektrických, elektromagnetických a termodynamických polí. Vakuové vypínače zajišťují stálou a spolehlivou vypínací funkci. Taktéž v oblasti chránění, řízení a komunikace došlo k mnoha technologickým proměnám. Od elektromechanických relé přes zařízení založená na tranzistorech, později na jednoúčelových mikroprocesorech, až po dnešní multifunkční vysoce výkonná mikroprocesorová inteligentní elektronická zařízení. Pouze oblast měření proudů a napětí setrvala z technologického hlediska posledních 40 let beze změny. K dominujícím měřícím technologiím dneška stále ještě patří indukčně založené transformátory proudu a napětí. Byly sice provedeny některé pokusy k obměně technologie měření jako takové, nicméně bez dosažení úspěchu. Tato dizertační práce je zaměřena na poskytnutí nového náhledu na alternativní technologii měření v elektrických sítích a ve vzduchem izolovaných vysokonapěťových rozváděčích, kterou lze využít jak pro měření proudu, tak i napětí. Tato práce vysvětluje, proč Rogowského cívky, odporové a kapacitní děliče jsou tou správnou volbou a měly by být použity ve vysokonapěťových rozváděčích a podrobně analyzuje přesnost měření a jejich příslušné meze. Dále tato práce popisuje, že pro nasazování nových měřících technologií musí být postupováno systematicky. Senzory připojené k inteligentním elektronickým přístrojům a schopností komunikace založené na IEC 61850 spolu s vysokorychlostní komunikační sběrnicí Ethernetu vytvoří systém, který zjednoduší a sjednotí konstrukci rozváděčů a umožní oddělit aspekty projektování měření od studie zkratových selektivit. V práci je také uveden příklad, jak tento nový systém může přinést změny a zjednodušení do oblastí projektování a řízení. V této práci jsou popsány výsledky několikaletého úsilí při stanovení nových měřících a digitalizovaných přístupů ve vysokonapěťových rozváděčích pod autorovým vedením. Toto úsilí také vedlo k uvedení nového produktu – UniGear Digital - konceptu od ABB. Závěrečná část práce demonstruje praktické nasazení všech výsledků v této práci při skutečných aplikacích.
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