Optimization of operating conditions of third harmonic ground-fault protection system of generator-transformer unit with two-states transverse parameters

Such an optimization analysis of the operating conditions of the ground-fault protection excited by the third harmonic voltage for the two-state system of the generator-transformer unit transverse parameters is presented in this paper. The analysis was made for a unit in which a change in its transverse branch parameters occurs as a result of generator breaker switching operations. The optimization analysis has shown that effective ground-fault protection of the generator stator windings is possible, regardless of the operating conditions of the generator breaker.