Patent ID: 11946966
Assignee: SCHWEITZER ENGINEERING LABORATORIES, INC.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 10:
11. A method for protecting an electric power generation installation in an electric power delivery system, comprising:
obtaining, using a voltage sensor component, a voltage signal proportional to a voltage of a generator of the electric power generation installation;
quantifying, using a current sensor component, a measured current;
calculating, using a processor, a pre-fault standing error current using a measured current and a measured reference positive-sequence voltage;
storing, using a computer-readable storage medium, the standing error reference;
detecting, using the voltage sensor component, a ground fault using voltage signals from the voltage sensor component;
obtaining, using a a measured current
calculating an operating current by calculating a difference between a measured current and the pre-fault standing error current;
determining a direction to the ground fault based on the difference between the measured current and the pre-fault standing error current; and
implementing, using a protective device, a protective action based on the direction to the ground fault.