Phase displacement of 60 degree during Fault
Phase displacement of 60 degree during Fault
(OP)
1. In the event of a ground fault in one phase in ungrounded systems, the phase-to-ground voltage in the remaining two phases is now equal to the phase-to-phase voltage with a displacement of 60 degrees.
2. Similarly, In the case of star connected motor or capacitor, on complete short circuit of one of the phase winding results in the remaining two phases attaining phase-to-phase voltage with a displacement of 60 degrees.
I can understand the unfaulted phases attaining the phase to phase voltage but I couldn't understand the phase displacement of 60 degrees.
Thank you.
2. Similarly, In the case of star connected motor or capacitor, on complete short circuit of one of the phase winding results in the remaining two phases attaining phase-to-phase voltage with a displacement of 60 degrees.
I can understand the unfaulted phases attaining the phase to phase voltage but I couldn't understand the phase displacement of 60 degrees.
Thank you.






RE: Phase displacement of 60 degree during Fault
Regards
mgtrp
RE: Phase displacement of 60 degree during Fault
This image is how i had it explained to me that helped me understand this. Remember that the generator is trying to maintain the same potential difference between poles. So if one pole is shorted during a ground fault you get the effect of sliding all three over.
Clay
Pardon my quick sketch isn't so good but i'm a visual person.
RE: Phase displacement of 60 degree during Fault
Unintended ungrounded system situation that happens on our system.
Varying amount of zero sequence voltage.
Sequence network for an SLG fault.
Voltages on an ungrounded system with a SLG fault.
RE: Phase displacement of 60 degree during Fault
Impressively extensive answer! Interesting there is no V2. Had to talk myself into recognizing that. Guess I am so used to thinking of all the negative sequence voltage you get during SLG fault on a solidly grounded system.
RE: Phase displacement of 60 degree during Fault
I had that locked and loaded from one of my wikia pages that I put together a couple years ago.
http://powerprotection.wikia.com/wiki/Analyzing_Fa...
The GIFS were put together using Alex Eachern's Power Quality Teaching Toy. It is what I use to get a visual idea of how sequence domain relates to the phasor domain and oscillography. It is worth playing with to get an idea how the two domains relate to each other.
http://www.powerstandards.com/PQTeachingToyIndex.p...