Any special requirement on 10kV switchgear which supply power to VSD 13MW 10kV induction motor. Need busbar protection, special protection, etc?
Tks in advance.
as requested by MAS2000 . Reload.http://files.engineering.com/getfile.aspx?folder=0e323b1a-b2f9-4e78-b0b8-54b97e2794e1&file=EWT_Earthing_Transformers.pdf
By introduce HRG system, it will increase zero sequence impedance. Consequence, the Single Phase Fault will be reduce.
Single phase fault = 3 V(0)/(Z1+Z2+ZO+ZF) where as Z1=Positive sequence impedance, Z2=negative sequence impedance, Z0=zero sequence impedance, V(0)=Prefault voltage.
Benefit...
so, from the above info, Can I say this 'the stated KVA rating for zig zag transformer is actually to stating the kVA rating for auxilary winding size'? (purpose of auxiliary winding is to supply power to substation LVAC services)
Pls comment.
Tks in advance.
Dear MAS2000, odlanor and Marmite,
This another info. Pls comment.http://files.engineering.com/getfile.aspx?folder=ccebded4-e67d-4e4c-9f24-53a0ec9b7894&file=EWT_Earthing_Transformers.rar
Dear MAS2000, odlanor and Marmite,
I just found some information on sizing zig zag transformer as attached. Pls comment.http://files.engineering.com/getfile.aspx?folder=96f5af8b-4786-473c-8dcc-ebf6ea5bf2ee&file=Grounding_Transformers.pdf
As far as I know, 3 phase fault current calculation is overcurrent relay setting.Meanwhile single phase fault is earth fault relay setting.
Correct me if i wrong.
Odlanor: There is no generator. It just distribution system network.
Waross: Thanks. But how to size my zigzag transformer? My NER current is 524.8A (33kV).I attached here the single line diagram for your reference.
Thanks in...
I will definitly to go with 3C cables reason for easy installation and cheap. But if client insisted to use 1C cable, i will follow them. But will remain them about the cost.
Technically, i did not see any different.I have experience to lay VFD to 800kW (6.6kV) induction motor.
I got 30MVA YNd1 stepdown transformer 132/33kV. The primary side is YN dan the secondary side is delta. The primary side neutral will be solid earth meanwhile secondary side I need zig-zag transformer to create artificial earthing (later will connect to NER). By doing this my earthfault relay...
