Abstract
The possibility of verifying the inductive voltage transformer (IVT) precision class during its operational life by means of simple excitation and short circuit tests is shown. By this way, the transportation of such equipment to laboratories or factories for new calibrations is avoided. As IVT precision is function of geometric parameters and material characteristics such as winding resistivity, core permeability and others, if they do not change, there is no reason to expect modifications in the precision of the equipment. After a critical analysis, is intended to demonstrate and experimentally verify that excitation and short-circuit test are sufficient to detect any modification in the above parameters. If such alteration are not detected, it is possible to assure that the equipment maintains its specified class of precision. The Moellinger and Gewecke method is used in order to determine the actual value of turns ratio and the separate leakage reactance of primary winding. These parameters are not easily obtainable in practice. The present Brazilian Rule for IVT does not mention any method which permits the determination os such parameters. Comparison of errors obtained by the present method with those found with Schering-Alberti Bridge, showed that this methodology is effective and useful mainly
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Citation Formats
Silva, Izael Pereira da.
A proposal of verifying of an inductive voltage transformers precision class; Uma proposta de verificacao da classe de exatidao de transformadores de potencial indutivos.
Brazil: N. p.,
1997.
Web.
Silva, Izael Pereira da.
A proposal of verifying of an inductive voltage transformers precision class; Uma proposta de verificacao da classe de exatidao de transformadores de potencial indutivos.
Brazil.
Silva, Izael Pereira da.
1997.
"A proposal of verifying of an inductive voltage transformers precision class; Uma proposta de verificacao da classe de exatidao de transformadores de potencial indutivos."
Brazil.
@misc{etde_20137839,
title = {A proposal of verifying of an inductive voltage transformers precision class; Uma proposta de verificacao da classe de exatidao de transformadores de potencial indutivos}
author = {Silva, Izael Pereira da}
abstractNote = {The possibility of verifying the inductive voltage transformer (IVT) precision class during its operational life by means of simple excitation and short circuit tests is shown. By this way, the transportation of such equipment to laboratories or factories for new calibrations is avoided. As IVT precision is function of geometric parameters and material characteristics such as winding resistivity, core permeability and others, if they do not change, there is no reason to expect modifications in the precision of the equipment. After a critical analysis, is intended to demonstrate and experimentally verify that excitation and short-circuit test are sufficient to detect any modification in the above parameters. If such alteration are not detected, it is possible to assure that the equipment maintains its specified class of precision. The Moellinger and Gewecke method is used in order to determine the actual value of turns ratio and the separate leakage reactance of primary winding. These parameters are not easily obtainable in practice. The present Brazilian Rule for IVT does not mention any method which permits the determination os such parameters. Comparison of errors obtained by the present method with those found with Schering-Alberti Bridge, showed that this methodology is effective and useful mainly when precision test equipment (such as A C relation bridge, standard transformer, standard burdens) are not available, and it is necessary to verify a transformer condition or even decide about a non-accordance between two results founded in laboratories through conventional methods. Several discussions about transformer models are also included, in particular the decomposition method, which, being essentially different from the T equivalent model, shows interesting aspects of transformer analysis. Two other points of special interest are: the critical analysis of the Moellinger and Gewecke method described at part 3.5 and its possible insertion in the NBR 6820/1992 and the study of magnetic field lines in windings with non-negligible dimensions described at part 3.2. (author)}
place = {Brazil}
year = {1997}
month = {Jul}
}
title = {A proposal of verifying of an inductive voltage transformers precision class; Uma proposta de verificacao da classe de exatidao de transformadores de potencial indutivos}
author = {Silva, Izael Pereira da}
abstractNote = {The possibility of verifying the inductive voltage transformer (IVT) precision class during its operational life by means of simple excitation and short circuit tests is shown. By this way, the transportation of such equipment to laboratories or factories for new calibrations is avoided. As IVT precision is function of geometric parameters and material characteristics such as winding resistivity, core permeability and others, if they do not change, there is no reason to expect modifications in the precision of the equipment. After a critical analysis, is intended to demonstrate and experimentally verify that excitation and short-circuit test are sufficient to detect any modification in the above parameters. If such alteration are not detected, it is possible to assure that the equipment maintains its specified class of precision. The Moellinger and Gewecke method is used in order to determine the actual value of turns ratio and the separate leakage reactance of primary winding. These parameters are not easily obtainable in practice. The present Brazilian Rule for IVT does not mention any method which permits the determination os such parameters. Comparison of errors obtained by the present method with those found with Schering-Alberti Bridge, showed that this methodology is effective and useful mainly when precision test equipment (such as A C relation bridge, standard transformer, standard burdens) are not available, and it is necessary to verify a transformer condition or even decide about a non-accordance between two results founded in laboratories through conventional methods. Several discussions about transformer models are also included, in particular the decomposition method, which, being essentially different from the T equivalent model, shows interesting aspects of transformer analysis. Two other points of special interest are: the critical analysis of the Moellinger and Gewecke method described at part 3.5 and its possible insertion in the NBR 6820/1992 and the study of magnetic field lines in windings with non-negligible dimensions described at part 3.2. (author)}
place = {Brazil}
year = {1997}
month = {Jul}
}