Ground distance - mutual inductance
Ground distance - mutual inductance
(OP)
I have two parallel lines that have mutual inductance and this is making the impedance seen by my ground distance relay higher than it actually for a fault on the remote bus. I am wanting to expand my zone 2 to cover maybe 40% instead of 25% of the next shortest segment in order to make sure that a line end fault will trip on zone 2 if both lines are in service. I also have fault current coming in from the other lines that is affecting the apparent impedance of how far I am going into the next line. I am looking at several scenarios (wind gen. out,ect) and just eyeballing the zones so that they operate correctly when one or both lines are in service with or without wind generation. Is this usually how it is done?






RE: Ground distance - mutual inductance
RE: Ground distance - mutual inductance
1. Are you suggesting that due to parallel line configurations that Zone 2 ground mho set at 120% of the asscociated impedance may not operated for a remote end fault ?
3. Does your lines haave a sky wire system on ground return through earth ?