Transformer paralleling
Transformer paralleling
(OP)
Can I operate two transformers; 3MVA 440 Volts, 50 Hz, 6% impedance and 4MVA 440volts, 50Hz, 7% impedance; in parallel?
If yes what will be the percentage load sharing by each of them?
If yes what will be the percentage load sharing by each of them?






RE: Transformer paralleling
RE: Transformer paralleling
Usually, recommended 10% difference between Uk%.
possible check oveload and undeload situation.
according:
Uk% for both=(3+4)/( 3/6+ 4/7)=6.54%
S1=3x6.54/6=3.28
S2=4x6.54/7=3.72
RE: Transformer paralleling
If the X/R ratios are not equal the total allowable load will be less than 6.43 MVA.
Bill
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"Why not the best?"
Jimmy Carter
RE: Transformer paralleling
The load will be shared depending- but only a bit- on load pf. If 440 V is the rated transformer voltage the Load voltage will be less due to the drop voltage on transformers.
For instance if the rated Load Sload= 7 MVA and pf=0.8 then S1=3.125 and S2=3.57 MVA. But if pf=0.9 then S1=3.154 MVA and S2=3.604 MVA.