Jensen,
Excellent and informative post. We have communications running everywhere, and since we have phase distance relays as a backup to pilot wire, we dont run POTT schemes on them. On a 21G relay it seeme it would be best to run a communications-assisted scheme.
You mention a reasonable...
David,
Thanks for your thoughts. Seems like our line protection philosophy is similiar to your company's. I would assume that if we changed our philosophy to using ground distance in areas, we would still have a directional ground, although it would be backed off somewhat.
Slava,
We currently use pilot wire schemes backed up by distance relays for phase faults. Our system is solidly grounded and we do have communications on both ends for pilot wire (and sometimes POTT schemes).
Thanks for your input,
Steve
Hi Slava,
Thank you for replying. The lines in question are 69 kV, short (7 miles and under for the most part), and it is a looped system. There might be some mutual coupling involved which could possibly create overreach/underreach situations.
Thanks,
Steve
I am attempting to research the pros and cons of ground distance relaying versus directional ground overcurrent (which we currently use).
I am looking for any/all sources that discusses the benefits as well as any pitfalls that might emerge from ground distance relaying.
As stated earlier, we...
