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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Prote??o de sobrecorrente direcional utilizando transformada wavelet

Leal, M?nica Maria 23 January 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-04-03T19:47:15Z No. of bitstreams: 1 MonicaMariaLeal_DISSERT.pdf: 2155852 bytes, checksum: a4bb5637a35beb7a7479b8533dee8dd8 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-04-06T20:06:37Z (GMT) No. of bitstreams: 1 MonicaMariaLeal_DISSERT.pdf: 2155852 bytes, checksum: a4bb5637a35beb7a7479b8533dee8dd8 (MD5) / Made available in DSpace on 2017-04-06T20:06:37Z (GMT). No. of bitstreams: 1 MonicaMariaLeal_DISSERT.pdf: 2155852 bytes, checksum: a4bb5637a35beb7a7479b8533dee8dd8 (MD5) Previous issue date: 2017-01-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Tradicionalmente, a principal prote??o utilizada nos sistemas el?tricos de pot?ncia ? n?vel de distribui??o ? a prote??o de sobrecorrente, devido sua simplicidade e baixo custo. No entanto, com a recente inser??o de geradores distribu?dos no sistema, o sentido do fluxo de pot?ncia pode ser variado de acordo com o local de ocorr?ncia da falta, sendo insuficiente, para algumas aplica??es, avalia??o apenas das amplitudes das correntes de falta. Ent?o, um m?dulo direcional pode ser adicionado para fornecer informa??o do sentido de ocorr?ncia da falta, se ? frente ou reversa ao ponto de medi??o das correntes e tens?es. Portanto, prop?e-se nesta disserta??o de mestrado a reconstru??o das unidades de sobrecorrente direcional de fase, de sequ?ncia positiva, negativa e zero baseadas na transformada wavelet discreta redundante, com a qual ? poss?vel recriar as unidades de sobrecorrente cl?ssicas por meio das energias dos coeficientes escala das correntes e as unidades direcionais cl?ssicas por meio dos coeficientes escala das tens?es e correntes, o que otimiza a prote??o pois n?o conta com alguns inconvenientes provenientes da transformada de Fourier discreta. Para avalia??o do m?todo proposto, foi utilizando o sistema de 30 barras do IEEE com gera??o distribu?da, assim como, o sistema de 230 kV do IEEE ? par?metros distribu?dos. / Traditionally, the primary protection used in low voltage power systems, as distribution systems, is the overcurrent protection due to its simplicity and low cost. However, in these recent years, the number of distributed generation connected to the system has been growing, which changes the complexity of the system and require a directional module to complement the diagnostic about the fault, providing information whether the fault is forward or reverse according to a reference point. Therefore, in this work is proposed a directional overcurrent protection module based on the stationary discrete wavelet transform. This tool could recreate the standard directional overcurrent protection using just currents and voltages scaling coefficients (low frequency), and the overcurrent protection is recreated by using currents scaling coefficients energy, which overcomes some drawbacks by using discrete Fourier transform. The proposed method was evaluated on the IEEE 30 bus model with distributed generator and the IEEE 230 kV systems analysis with distributed parameters.

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