Transformer
Transformer
(OP)
Hi,
IF case of a 20/26 MVA Oil natural fan cooled transformer, if the base impedance is %z =7 on 20 MVA, and when the loading is 26 MVA, will the percenatage impedance change and so will the fault contribution of Transformer. I mean, will a transformer generate different fault current depending upon its loading. Please advise.
IF case of a 20/26 MVA Oil natural fan cooled transformer, if the base impedance is %z =7 on 20 MVA, and when the loading is 26 MVA, will the percenatage impedance change and so will the fault contribution of Transformer. I mean, will a transformer generate different fault current depending upon its loading. Please advise.






RE: Transformer
RE: Transformer
Thanks
RE: Transformer
RE: Transformer
It is correct that if you choose 26MVA as your base then the %Z will change numerically. For that matter you can choose even 100MVA as your base too. The fault current will not change.
RE: Transformer
Another way, full load current at 20 MVA is 7% of the available fault current.
Full load current at 26 MVA is 9.1% of the available fault current.
respectfully
RE: Transformer
Conversion of the impedance is required to reflect the new base values. Should not be significant difference in the SC calculation with difference base values.