HV or LV
HV or LV
(OP)
I have an application that requires a genset to support the load on a cement works. The mill has a 2.8 MW motor at 6.6kV. The site auxiliaries and other standing load is 1.5MW at 400V. This genset will run at base load and let the utility take any starting loads.
Should I generate at 6.6kV and transform down to support the site load or generate at 400V and transform up to support the mill motor? The gensets haven’t been speced yet but will be two or three 1.5 or 1.8 MW units.
Should I generate at 6.6kV and transform down to support the site load or generate at 400V and transform up to support the mill motor? The gensets haven’t been speced yet but will be two or three 1.5 or 1.8 MW units.






RE: HV or LV
There may be other factors.
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RE: HV or LV
RE: HV or LV
IMHO there should not be any significant performance difference as long as the transformer is sized correctly. Simply a matter of economics. I'd sketch it up both ways and see which one saves money.
Don't forget to post and let us know what you wind up doing!
Good on ya,
Old Dave
RE: HV or LV
My experience is that a MV genset in this size range will be about 15% more costly than an equivalent 400V genset.
RE: HV or LV
RE: HV or LV
Since more load at 6.6kV level, you will be able to save on power losses if the generators are specified to be 6.6kV.
You could be saving on transformer cost as the required transformer could be rated 2MVA, 6.6/415V and not rated 4MVA, 400/6.9kV.
RE: HV or LV
RE: HV or LV
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