Patent ID: 11887774
Assignee: nan
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 16:
17. The system of claim 11, wherein combining the supplemented GIC signal with the second harmonic blocking signal using AND logic to determine the supplemented second harmonic blocking signal comprises:
determining a ratio of the second harmonic to a first harmonic component of the differential current for each phase, and outputting a high second harmonic blocking signal where the determined ratio is greater than a predetermined second harmonic threshold, the first harmonic component comprising a fundamental frequency;
combining the second harmonic blocking signal with the supplemented GIC signal using AND logic to output a supplemented second harmonic blocking signal; and
combining a trip request signal with the supplemented second harmonic blocking signal using AND logic to output the trip signal for electrically tripping the transformer.