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

Claim 0:
1. A system for protecting an electric power generation installation in an electric power delivery system, comprising:
a protective device in electrical communication with a generator of the electric power generation installation, comprising:
a voltage sensor component to obtain a voltage signal corresponding with a voltage of the first generator of the electric power generation installation;
a current sensor component to quantify a measured current;
a processor; and
a computer-readable storage medium in communication with the processor, the voltage sensor component, and the current sensor component, comprising instructions that when operated cause the processor to:
calculate a pre-fault standing error current using a measured current and a measured reference positive-sequence voltage;
store the standing error reference on the computer-readable storage medium;
detect a ground fault using voltage signals from the voltage sensor component;
calculate an operating current by calculating a difference between the measured current and the pre-fault standing error current;
determine a direction to the ground fault based on the difference between the measured current and the pre-fault standing error current; and
implement a protective action based on the direction to the ground fault.