Two DNO 11Kv/400/230v transformers on different HV lines originally supplied two separate buildings on an industrial site. The two separate buildings are now one large steel framed one. So we have two DNO intakes and no clear demarcation within the installation. I remember reading somewhere about issues arising in such situations but cannot find the article. I am keen to establish if any issues are serious enough to seek alternatives. One of the intakes has a Biomass plant feed-in with g59 relay. Both intakes are circa 1MVA.
I had presumed, perhaps naively, that the supplies were not actually going to be paralleled but the OP does not state, so I hadn't considered vector group of the transformers.
With that said, if the TXs were by default sharing a return path via steel frame or other earthing, would the different vector groups of differing TXs cause any zero sequence currents to be at differing angles? Or have I just made that up?
I had presumed, perhaps naively, that the supplies were not actually going to be paralleled but the OP does not state, so I hadn't considered vector group of the transformers.
With that said, if the TXs were by default sharing a return path via steel frame or other earthing, would the different vector groups of differing TXs cause any zero sequence currents to be at differing angles? Or have I just made that up?
