I am looking at the results for an earth grid study for a 50Hz substation.
- Primary Voltage (Vp) = 11,000 V
- Secondary Voltage (Vs) = 415 V
- Secondary Fault Current (If)= 24 kA
- Secondary Grid Current (Ig)= 2.4 kA
- Ground Resistance (Rg) = 1.7 Ω
- Calculated Ground Potential Rise (GPR) = 4080 V
I understand that GPR = Ig x Rg, but what is the rationship between Vp/Vs and GPR?
If 4000+ V is available at the earth grid, wouldn't current flow back up the faulted conductor to the source?
Is it related to different reference points?
I would appreciate it if anyone could help me get my head around this one.