Help me getting the the magnetizing circuit of a transformer
Help me getting the the magnetizing circuit of a transformer
(OP)
I want to get the magnetizing circuit gm & bm of a transformer, If we have Ploss (no load loss) in watts and Ie (exciting current) in pu (based on nominal voltage and MVA base)
Here is the definition from PSSE documentations:
MAG1, MAG2 MAG1 is the no load loss in watts and MAG2 is the exciting current in pu on winding one to two base MVA (SBASE1-2) and nominal voltage (NOMV1).
Here is my derivation :
Ploss pu = Ploss/(MVAbase in watts)
Vpu * Vpu * gm = Ploss pu
Because V is the nominal voltage so Vpu = 1 pu, we get gm as Ploss pu
We have Y magnetizing circuit as gm + j bm
Yabs = sqrt(gm * gm + bm * bm) = Ipu/Vpu = Ipu (as Vpu = 1)
sqrt(gm * gm + bm * bm) = Ipu
Then bm = sqrt(Ipu * Ipu - gm * gm)
What is wrong with these calculations?
Here is the definition from PSSE documentations:
MAG1, MAG2 MAG1 is the no load loss in watts and MAG2 is the exciting current in pu on winding one to two base MVA (SBASE1-2) and nominal voltage (NOMV1).
Here is my derivation :
Ploss pu = Ploss/(MVAbase in watts)
Vpu * Vpu * gm = Ploss pu
Because V is the nominal voltage so Vpu = 1 pu, we get gm as Ploss pu
We have Y magnetizing circuit as gm + j bm
Yabs = sqrt(gm * gm + bm * bm) = Ipu/Vpu = Ipu (as Vpu = 1)
sqrt(gm * gm + bm * bm) = Ipu
Then bm = sqrt(Ipu * Ipu - gm * gm)
What is wrong with these calculations?






RE: Help me getting the the magnetizing circuit of a transformer
RE: Help me getting the the magnetizing circuit of a transformer
RE: Help me getting the the magnetizing circuit of a transformer
If we may neglect Z1=R1+jX1 , I'2o [and Z'2=R'2/s+jX'2] then
I1o=V1*(1/Rfe-j/Xmiu) ;gm=Zb/Rfe bm=Zb/Xmiu
[Zb=Vbase^2/MVAbase ]and then
Ipu=sqrt(gm^2+bm^2) indeed.
The total error may be 5-20% or more.See Attachment
Best Regards