Análise comparativa de metodologias para mitigação de faltas entre espiras em geradores síncronos de fase dividida

Abstract

Abstract: This work aims to compare various schemes based on differential protection (ANSI function 87) applied to safeguard against faults turn-to-turn in synchronous generators. Six schemes were employed based on two methodologies of differential protection: simple and percentage. Computational simulations utilized the synchronous generator model with two windings per phase from the HYPERSIM software, the real-time digital simulator from OPAL-RT Technologies. Coil faults were simulated ranging from 50% to 1% winding suppression to assess the effectiveness of each scheme. Additionally, simulations of faults external to the generator were conducted to evaluate scheme safety. Results indicate that, regardless of the methodology, faults with suppressions less than 8% went undetected. In security tests, when errors were introduced into the current transformers, all schemes acted improperly for faults external to the generator. The methods that yielded better results were those monitoring both windings of the phase or when the faulty phase winding was under analysis.