Patent ID: 9612268
Date: 2017-04-04
CPC Classifications: G01R

Claim:
1. A method of measuring a ground potential rise of a substation, comprising: coupling a first side of a first potential transformer to the substation ground grid; coupling a first side of a second potential transformer to the substation ground grid; coupling a second side of the first potential transformer to a first end of a first wire; coupling a second side of the second potential transformer to a first end of a second wire; coupling a second end of the first wire to a first ground rod; coupling a second end of the second wire to a second ground rod; delivering the first ground rod into the earth at a first depth; and delivering the second ground rod into the earth at a second depth; wherein the first potential transformer measures a first voltage and the second potential transformer measures a second voltage, further comprising determining the ground potential rise to be the second voltage when the first voltage differs from the second voltage; and obtaining a proper voltage for calculating an apparent impedance by comparing a phase of the ground potential rise to a phase of the second voltage.