Reajuste das lógicas do sistema especial de proteção associado a Itaipu 60Hz e as linhas de transmissão entre Foz do Iguaçu e Tijuco Preto

Abstract

The present work aims to analyze the adjustments of some of the logics associated with the special protection scheme for the 765kV trunk. Using the batch simulation methodology developed by Dos Santos (2022), within the context of the 765kV Special Protection Scheme (SEP), it was possible to simulate potential events related to double and triple fault logics in the Foz do Iguaçu - Ivaiporã and Itaberá - Tijuco Preto sections. The objective of this study is to evaluate the possibility of increasing the adjustments currently used by the 765kV SEP logics, which are limited by overload criteria. The adjustments of the current protection system were designed considering the overload of the remaining circuit. The main purpose of this work is to demonstrate the difference that adjustments can achieve when quantified in terms of dynamic criteria rather than equipment limit criteria. Increasing the adjustment values for initiating generator unit tripping can have a positive impact on both the Brazilian national interconnected system and Itaipu Binacional, as the generator units will be less exposed to tripping. Additionally, to reduce generator unit tripping at Itaipu 60Hz, a study explored the insertion of pick-up values for initiating generator unit tripping. The obtained value for blocking generator unit tripping was considerably high (4,000MW in terms of southeast flow), representing a significant reduction in exposure of Itaipu generator units to tripping. Complementarily, this pick-up value also addressed another existing issue by preventing generator unit tripping during double faults in the Foz do Iguaçu - Ivaiporã section under south importing scenarios (RSUL).