Fault component of third harmonic voltage based ground fault protection for generators

To improve the sensitivity of ground fault protection for generators, this paper proposes a novel protection based on the fault components of third harmonic voltage at the terminals and neutral. Two types of protection scheme, i.e. amplitude and phase comparison, are given. The results of simulation and experiment verify that the novel protection is with high sensitivity, is immune to the operating condition of generator, and is of robustness.