Hrg ground fault detector and method

A HRG ground fault detector configured to detect a ground fault in a High Resistance Ground (HRG) system, the HRG ground fault detector comprising:

• a first input A adapted to be coupled to a first phase PHA of the HRG system;
• a second input B adapted to be coupled to a second phase PHB of the HRG system;
• a third input C adapted to be coupled to a third phase PHC of the HRG system, with the HRG ground fault detector generating a simulated neutral voltage VN′ from the first phase PHA, the second phase PHB, and the third phase PHC, wherein the simulated neutral voltage VN′ comprises a zero voltage potential when the first phase PHA, the second phase PHB, and the third phase PHC are equal;
• an integrator coupled to the neutral node N′ and configured to integrate the simulated neutral voltage VN′, wherein the integrated voltage VINT is substantially constant in amplitude regardless of a frequency at the first phase PHA, the second phase PHB, and the third phase PHC;
• a processing system coupled to the integrator, with the processing system configured to compare the integrated voltage VINT to a predetermined fault voltage threshold and detect a HRG ground fault in the HRG system if the integrated voltage VINT exceeds the predetermined fault voltage threshold.

A High Resistance Ground (HRG) ground fault detection method configured to detect a HRG ground fault in a HRG system, the ground fault detection method comprising:

• a HRG ground fault detector receiving a first phase PHA, a second phase PHB, and a third phase PHC from the HRG system;
• the HRG ground fault detector generating a simulated neutral voltage VN′ from the first phase PHA, the second phase PHB, and the third phase PHC, wherein the simulated neutral voltage VN′ comprises a zero voltage potential if the first phase PHA, the second phase PHB, and the third phase PHC are equal;
• the HRG ground fault detector comparing the simulated neutral voltage VN′ to a predetermined fault voltage threshold;
• and
• the HRG ground fault detector detecting a HRG ground fault in the HRG system if the simulated neutral voltage VN′ exceeds the predetermined fault voltage threshold.