Numerical relays are the result of the application of microprocessor technology in relay industry. Numerical relays have the ability to communicate with its peers, are economical and are easy to operate, adjust and repair. Modeling of digital and numerical relays is important to adjust and settle protection equipment in electrical facilities and to train protection personnel. Designing of numerical relays is employed to produce new prototypes and protection algorithms. Computer models of numerical relays for the study of protection systems are greatly enhanced when working along with an electromagnetic transient program (emtp). A literature survey has revealed that previous modeling techniques presented a lack of automation in the generation of relay models, or show high complexity in linking the numerical relay models with the power system modeled in the emtp. <p> This thesis describes a new approach of modeling and designing of numerical relays. The proposed methodology employs a Visual C++-based program (PLSA) to obtain from the user the specifications of the relay to be designed, and to process this information to generate the FORTRAN code that represents the functional blocks of the relay. This generated code is incorporated in a PSCAD/EMTDC case using a resource called component, which facilitates the creation of user-custom models in PSCAD/EMTDC. Convenient electrical and logical signals are connected to the inputs and outputs of the PSCAD/EMTDC component. Further additions of digital relay models into the PSCAD/EMTDC case constitute the protection system model. The thesis describes a procedure for designing distance and differential relay models, but the methodology may be extended to design models of other relay elements. <p> A number of protection system studies were performed with the structure created with the proposed methodology. Adjustment of distance and differential relays were studied. Relay performance under CT saturation and the effects of the removal of anti-aliasing analog filter were investigated. Local and remote backup distance protection of transmission lines was simulated. The adjustment of differential protection of power transformer to overcome the effects of inrush current was performed. Power transformer differential protection responses to internal and external faults were considered. <p>Additionally, a set of tests were performed to investigate the consistency of the relay models generated with the proposed methodology. The results showed that the numerical relay models respond satisfactorily according with the expected results of the tests.

Numerical relays are the result of the application of microprocessor technology in relay industry. Numerical relays have the ability to communicate with its peers, are economical and are easy to operate, adjust and repair. Modeling of digital and numerical relays is important to adjust and settle protection equipment in electrical facilities and to train protection personnel. Designing of numerical relays is employed to produce new prototypes and protection algorithms. Computer models of numerical relays for the study of protection systems are greatly enhanced when working along with an electromagnetic transient program (emtp). A literature survey has revealed that previous modeling techniques presented a lack of automation in the generation of relay models, or show high complexity in linking the numerical relay models with the power system modeled in the emtp. <p> This thesis describes a new approach of modeling and designing of numerical relays. The proposed methodology employs a Visual C++-based program (PLSA) to obtain from the user the specifications of the relay to be designed, and to process this information to generate the FORTRAN code that represents the functional blocks of the relay. This generated code is incorporated in a PSCAD/EMTDC case using a resource called component, which facilitates the creation of user-custom models in PSCAD/EMTDC. Convenient electrical and logical signals are connected to the inputs and outputs of the PSCAD/EMTDC component. Further additions of digital relay models into the PSCAD/EMTDC case constitute the protection system model. The thesis describes a procedure for designing distance and differential relay models, but the methodology may be extended to design models of other relay elements. <p> A number of protection system studies were performed with the structure created with the proposed methodology. Adjustment of distance and differential relays were studied. Relay performance under CT saturation and the effects of the removal of anti-aliasing analog filter were investigated. Local and remote backup distance protection of transmission lines was simulated. The adjustment of differential protection of power transformer to overcome the effects of inrush current was performed. Power transformer differential protection responses to internal and external faults were considered. <p>Additionally, a set of tests were performed to investigate the consistency of the relay models generated with the proposed methodology. The results showed that the numerical relay models respond satisfactorily according with the expected results of the tests.

Orientador: Walmir de Freitas Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-09T14:02:58Z (GMT). No. of bitstreams: 1 Salles_NewtonJosede_M.pdf: 3608719 bytes, checksum: b040f49f75941ae11cb16f7beb51b76d (MD5) Previous issue date: 2007 / Resumo: A necessidade de desenvolvimento de modelos dinâmicos para estudos de sistemas de proteção de redes de distribuição de energia elétrica tem sido acentuada, recentemente, devido ao grande número de geradores síncronos que estão sendo conectados nestas redes. Assim, o objetivo desta dissertação de mestrado é desenvolver uma biblioteca de modelos dinâmicos para representar os principais relés empregados em sistemas de proteção de redes de distribuição e subtransmissão de energia elétrica na presença de geradores síncronos. Os modelos desenvolvidos são adequados para utilização juntamente com programas de simulação de transitórios eletromagnéticos de sistemas de potência (simulação com realimentação ? close loop), para verificar a influência do sistema de proteção no desempenho da rede, ou independentemente (simulação sem realimentação - open loop), para investigar os algoritmos empregados no relé ou para validar os modelos desenvolvidos. A complexidade adotada para representar os diversos tipos de relés foi decidida tendo-se em mente que tais modelos devem ser precisos o suficiente para desenvolvimento de pesquisas na área de proteção de sistemas de distribuição na presença de geradores síncronos e simples o suficiente para que eles possam ser utilizados para ensino da teoria de sistemas de proteção de redes de distribuição em nível de graduação e pós-graduação. Os modelos foram desenvolvidos para uso no ambiente Matlab/Simulink. Conseqüentemente, estes modelos podem ser utilizados com diversos programas de simulação de transitórios eletromagnéticos tais como o PSCAD/EMTDC, o SimPowerSystems e o ATP. Os modelos desenvolvidos foram validados através da comparação dos resultados obtidos por simulação com o comportamento real de relés comerciais. Adicionalmente, tal validação dos modelos foi realizada através de duas metodologias. Na primeira metodologia, dados obtidos em campo através de oscilografias de relés foram utilizados como entrada para os modelos desenvolvidos. Então, o comportamento do relé comercial foi comparado com o comportamento do modelo simulado. Na segunda metodologia, os dados de tensão e corrente foram gerados através de simulações de transitórios eletromagnéticos utilizando-se o ATP. Então, tais dados foram utilizados para verificar o comportamento de um relé comercial, através do uso de caixa de teste, e do relé simulado. Os resultados comprovam que os modelos desenvolvidos são suficientemente precisos para determinar o comportamento de relés comerciais operando em campo / Abstract: Recently, the need for the development of protection device dynamic models for analysis of distribution network protection systems has increased due to the usage of distributed generators. Therefore, the objective of this dissertation is to develop a dynamic model library torepresent the main relays used in the subtransmission and distribution network protection systems in the presence of synchronous generators. The developed models can be used with transient electromagnetic programs (close loop), in order to analyze the influence of the protection system on the network performance, or individually (open loop), in order to investigate new algorithms as well as to validate the models. The developed models are sufficiently detailed to conduct researches on distribution network protection in the presence of distributed generators, however, in the same time, they are simple enough to be used to teach undergraduate and graduate students. The models were developed to use with Matlab/Simulink. As a result, they can be used with several electromagnetic transient programs such as PSCAD/EMTDC, SimPowerSystems, and ATP. The developed models were validated by comparing the results obtained through simulation with the performance of real, commercial relays. Moreover, two approaches were used to validate the models. In the first one, field data obtained from relay oscillograms were used as an input to the developed models. Then, the commercial relay behavior was compared with simulated relay. In the second approach, voltage and current signals were generated by using the ATP. Then, these signals were used to verify the behavior of the commercial relays, through an amplifier, and of the developed model. The results show that the developed models are accurate enough to determine the behavior of commercial relays / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica