The present invention includes a method for providing ground fault protection to a generator. The method includes determining the existing state of the generator and second, determining the updated alarm or trip conditions of a relay connected to the generator in view of the existing state of the generator. This includes estimating a ratio of the magnitude of the 3rd harmonic neutral voltage to the magnitude of the 3rd harmonic terminal voltage of a generator, along with calculating the residual 3rd harmonic voltage from the estimated 3rd harmonic ratio. From this, a comparison is made between the energy of the residual voltage with a fractional energy of the 3rd harmonic neutral voltage. Based on this comparison, an alarm or trip condition is signaled when the energy of the residual voltage is greater than the fractional energy of the 3rd harmonic neutral voltage. The invention further includes adaptive relays and systems utilizing the adaptive relays, along with methods of producing power using the adaptive relays.
