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Differential Protection for Power Transformer
Bukvišová, Zuzana ; Wasserbauer, Vojtěch (referee) ; Orságová, Jaroslava (advisor)
This thesis explores power transformer protection and focuses on differential protection. It attempts to explain its principles and operating characteristic settings. The measurement was executed on devices SPAD 346 C and REF542plus, which can be used for differential protection. At the end, there is a comparison of results of operating characteristic measurement on both devices. Their function was tested at different cases, specifically when the differential current occurs in all phases or just one. The thesis includes a comparison of reaction times under fast increase of current. OMICRON CMC 256 plus was used as the test device. The data obtained by the measurement are processed in tables and charts.
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History of protection relays
Šafl, Pavel ; Koudelka, Jan (referee) ; Bukvišová, Zuzana (advisor)
The bachelor thesis deals with mapping the origin and history of electrical pro-tections. The work outlines the circumstances and the new types of protection. It expla-ins and introduces problems encountered in the development and operation of historical protections. On the overcurrent protection AB31, AT31 and REF615, the tripping characte-ristic was measured to evaluate and compare modern digital protection and historical electromagnetic protection. Dependent protection AB31 has been tested and measured for its dependent characteristics and the AT31 protection has been checked for short-circuit current capability. Both of these protections were compared and evaluated with the REF615 digital protection. The measurement results and calculations are processed into well-arranged tables and graphs that are part of the work. The last part of this thesis is the selection of suitable protections for describing and making small exposures.
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Testing of Transformer Differential Protection
Judas, Jan ; Těžký, Jiří (referee) ; Orságová, Jaroslava (advisor)
My bachelor thesis deals with the protection of a transformer, the main focus of the thesis is the differential protection of a transformer, the principle of its function, stabilization and the operating characteristic. I suggested a way of measuring the operating characteristic of the protection SPAD 346 C (developed) by ABB company. As far as measurement is concerned, I used the testing device TZO3, which was, as well as the tested protection, configurated by a computer, into which the results of single measurements were put. The testing was performed via a kind of a test known as ,,TREND“ test for 3 various configurations of operating characteristic of protection and each measurement was scaled for 2 different ,,TREND“ testings. Two marginal operating characteristics were configurated and the third characteritic was configurated approximately between 2 marginal configurations . An error in the calculations of measurement was shown. Since there were two ,,TREND“ tests of steepness performed, there was a calculation of reaction time of protection conducted/performed as well.. All measured and calculated data were processed to graphs in order to illustrate differences among single measurements. I also provided explanations and calculations of possibilities of elimination of increase of electric current within reaction time of protection at steeper increase of ,,TREND“ test.
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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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History of protection relays
Šafl, Pavel ; Koudelka, Jan (referee) ; Bukvišová, Zuzana (advisor)
The bachelor thesis deals with mapping the origin and history of electrical protections. The work outlines the circumstances and the new types of protection. It expla-ins and introduces problems encountered in the development and operation of historical protections. On the overcurrent protection AB31, AT31 and REF615, the tripping characte-ristic was measured to evaluate and compare modern digital protection and historical electromagnetic protection. Dependent protection AB31 has been tested and measured for its dependent characteristics and the AT31 protection has been checked for short-circuit current capability. Both of these protections were compared and evaluated with the REF615 digital protection. The measurement results and calculations are processed into well-arranged tables and graphs that are part of the work. The last part of this thesis is the selection of suitable protections for describing and making small exposures.
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Type test of a switching device
Knebl, Ladislav ; Dostál, Lukáš (referee) ; Valenta, Jiří (advisor)
Protection of the electrical ciruits in electrical installations by circuit breakers is the most common way of protecting circuits from overcurrents. In the low voltage installations, fuses were replaced by the circuit breakers. For this reason, it is important to put great emphases on their quality and user safety . This thesis deals with principle of the circuit breaker, its function, construction requirements and requirements for the type test, which the manufacturer needs to pass before release the device on market. These requrements are listed in Czech Technical Standard ČSN EN 60898-1. In this thesis, specific type of circuit breaker will be also described. Some sequences of tests described in the standard will be performed on that breaker.
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History of protection relays
Šafl, Pavel ; Koudelka, Jan (referee) ; Bukvišová, Zuzana (advisor)
The bachelor thesis deals with mapping the origin and history of electrical protections. The work outlines the circumstances and the new types of protection. It expla-ins and introduces problems encountered in the development and operation of historical protections. On the overcurrent protection AB31, AT31 and REF615, the tripping characte-ristic was measured to evaluate and compare modern digital protection and historical electromagnetic protection. Dependent protection AB31 has been tested and measured for its dependent characteristics and the AT31 protection has been checked for short-circuit current capability. Both of these protections were compared and evaluated with the REF615 digital protection. The measurement results and calculations are processed into well-arranged tables and graphs that are part of the work. The last part of this thesis is the selection of suitable protections for describing and making small exposures.
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History of protection relays
Šafl, Pavel ; Koudelka, Jan (referee) ; Bukvišová, Zuzana (advisor)
The bachelor thesis deals with mapping the origin and history of electrical pro-tections. The work outlines the circumstances and the new types of protection. It expla-ins and introduces problems encountered in the development and operation of historical protections. On the overcurrent protection AB31, AT31 and REF615, the tripping characte-ristic was measured to evaluate and compare modern digital protection and historical electromagnetic protection. Dependent protection AB31 has been tested and measured for its dependent characteristics and the AT31 protection has been checked for short-circuit current capability. Both of these protections were compared and evaluated with the REF615 digital protection. The measurement results and calculations are processed into well-arranged tables and graphs that are part of the work. The last part of this thesis is the selection of suitable protections for describing and making small exposures.
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Type test of a switching device
Knebl, Ladislav ; Dostál, Lukáš (referee) ; Valenta, Jiří (advisor)
Protection of the electrical ciruits in electrical installations by circuit breakers is the most common way of protecting circuits from overcurrents. In the low voltage installations, fuses were replaced by the circuit breakers. For this reason, it is important to put great emphases on their quality and user safety . This thesis deals with principle of the circuit breaker, its function, construction requirements and requirements for the type test, which the manufacturer needs to pass before release the device on market. These requrements are listed in Czech Technical Standard ČSN EN 60898-1. In this thesis, specific type of circuit breaker will be also described. Some sequences of tests described in the standard will be performed on that breaker.
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Differential Protection for Power Transformer
Bukvišová, Zuzana ; Wasserbauer, Vojtěch (referee) ; Orságová, Jaroslava (advisor)
This thesis explores power transformer protection and focuses on differential protection. It attempts to explain its principles and operating characteristic settings. The measurement was executed on devices SPAD 346 C and REF542plus, which can be used for differential protection. At the end, there is a comparison of results of operating characteristic measurement on both devices. Their function was tested at different cases, specifically when the differential current occurs in all phases or just one. The thesis includes a comparison of reaction times under fast increase of current. OMICRON CMC 256 plus was used as the test device. The data obtained by the measurement are processed in tables and charts.
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