Análise da atuação dos relés 50N e 59N no lado delta de transformadores em distintos cenários sob falta monofásica

Abstract

This undergraduate thesis proposes a comparative analysis of the neutral instantaneous overcurrent relay (50N) and the neutral instantaneous overvoltage relay (59N) using the ATPDraw software, with the aim of understanding their behavior under different scenarios of single-phase unbalances and single-phase line-to-ground faults. One of the main issues addressed is the measurement of the zero-sequence current (I0), carried out through a grounding transformer in zig-zag connection, linked to the delta side of the transformer, thus providing a neutral measurement point. For the acquisition of the residual neutral voltage, a potential transformer connected in broken-delta configuration is used. The results obtained allowed for a better understanding of the relationship between the system short-circuit level and the overcurrent and overvoltage values recorded.