Analysis of overexcitation relaying set up in synchronous generators for hydro power plants

This paper seeks to revise the concepts related to the overexcitation relaying in synchronous generators for hydro power plants and its coordination with the V/Hz limiter of the automatic voltage regulator (AVR). The methodology for the ANSI 24 protection function set up in hydro power plants is revisited. Finally, problems faced during the commissioning of a power plant in Brazil is discussed.