Requisitos de proteção quanto à tensão de restabelecimento transitória para disjuntores e religadores em uma rede de distribuição de energia

Abstract

This work presents a study on protection requirements regarding the Transient Recovery Voltage (TRV) for circuit breakers and reclosers on a power system distribution network. In view of the growth of changes in the Electric Power System (EPS), the demand for new operations and switching schemes, in addition to change in the topology of the networks, which pose challenges to the concessionaires, the need arises to understand the phenomenon of TRV and analyze means for mitigating the value and the growth rate. The proposed methodology consists of the evaluation of the technical standardization associated with medium voltage equipment, construction of standard envelopes, modeling and simulation of the phenomenon on an Electromagnetic Transient Program (EMTP) platform, followed by an explanation of the TRV supportability envelopes, then comparing, the presumed TRV with the specified by the standard. The equipment modeling and the simulation of the transient event was carried out in the Alternative Transient Program (ATP) software, considering the application of single-phase faults a few kilometers from the substation, which imposes thermal stresses on the switching devices, in addition to the ungrounded terminal three-phase fault, which determines the most severe dielectric conditions to the medium in the arc quenching chamber. The results showed that, in a single-phase ground fault scenario, all reclosers are exceeded by peak and, in a three-phase terminal ungrounded fault scenario, only one recloser and the circuit breaker were in non-compliance with the standard requirements. Summarizing the results, the insertion of capacitive surge cells and the exchange of equipment for another with a higher voltage class proved to be effective alternatives regarding the problems associated with the TRV