rick.conner
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the book definitely calculated the generator pu voltage wrong.
Though I am getting two different answers when working different ways so I might need a little lesson!
Give that the pu current is 0.059-0.01078j and the base is 240MVA. The generator Voltage line-line is 45kv and is the reference. They want to know what the complex power delivered is. the current is across a load several xfmr's down though who cares as it is given in pu!
1) convert I pu to the 45kv base which is 184 at an angle of -10.35, next V*conj(I)*sqrt(3) should give me the total 3-phase mva of 14+2.56j
2) if I convert the gen to pu, multiply sqrt(3)*Vpu*conj(Ipu) then (138/45)^2 so i convert to the 45kV side and then multiply by 240MVA I get 75+13.738j
help please - this is the first pu problem I've problems with and going crazy
Though I am getting two different answers when working different ways so I might need a little lesson!
Give that the pu current is 0.059-0.01078j and the base is 240MVA. The generator Voltage line-line is 45kv and is the reference. They want to know what the complex power delivered is. the current is across a load several xfmr's down though who cares as it is given in pu!
1) convert I pu to the 45kv base which is 184 at an angle of -10.35, next V*conj(I)*sqrt(3) should give me the total 3-phase mva of 14+2.56j
2) if I convert the gen to pu, multiply sqrt(3)*Vpu*conj(Ipu) then (138/45)^2 so i convert to the 45kV side and then multiply by 240MVA I get 75+13.738j
help please - this is the first pu problem I've problems with and going crazy