Load unbalance on the low side of a grounded wye-delta transformer
Load unbalance on the low side of a grounded wye-delta transformer
(OP)
If I have an unbalance condition (not a phase to ground fault but an unbalance, say an open phase conductor) on the low side of a grounded wye-delta distribution transformer (distribution system is impedance grounded through a zig-zag grounding transformer) how can I sense this unbalance? Will I see zero sequence current flow though the neutral on the high side of the transformer ? Does anyone know any good technical papers that address this ? Note the distribution system I am refering to is a three-wire system (not a four wire) with the zig-zag connected to the phase conductors.






RE: Load unbalance on the low side of a grounded wye-delta transformer
If you are trying to sense this from the wye side of your wye-delta transformer, I would think that the negative sequence current would be the most reliable.
But this is all of function of load current, since you don't have a shunt fault. If there is no load, there is no current and you won't see anything.
But then again, it's Friday afternoon, and I'm thinking more about beer than sequence currents.
RE: Load unbalance on the low side of a grounded wye-delta transformer
RE: Load unbalance on the low side of a grounded wye-delta transformer
RE: Load unbalance on the low side of a grounded wye-delta transformer
http://www.sandc.com/edocs_pdfs/edoc_025854.pdf