Ground Potential Rise

[3winding]

I am looking for reference material on ground potential rise. The system I am trying to calculate is an enclosure with communication equipment that is beneath a 25kV distribution line. I want to protect the communication link to a remote generation site with isolators at each end (positron). I want to calculate the GPR to see if I am within the ratings of the isolating device. Most of the reference material I have does not directly reference GPR. Does anyone know of a good reference?

 

[busbar]

Applicable material may be
IEEE Std 367-1996 …Determining the Electric Power Station Ground Potential Rise and Induced Voltage From a Power Fault
IEEE Std 80-2000 …Safety in AC substation grounding
IEEE Std 1050-1996 …Instrumentation and Control Grounding in Generating Stations

 

[rbulsara]

You are misinterpreting GPR. GPR is related to a ground fault condition for which 'busbar' is providing the references. It has nothing to do with induced noise/voltages.

What you should be worried about it effect of EMI/RFI (electromagnetic and radio frequecy intereference) from the power lines to with the comm equipment. You can measure magnetic field with a gauss meter. Contact firms that deals with EMI/RFI shiedling. It amounts to fortifying a ferrous encloure around comm equipment and effectively grounding it!!

I would try to move the comm equipment away from the MV lines. A few feet makes a world of difference. Some annoying problems have very simple solutions.

Good luck.