Nguon:

Idm=Sdm/can3.Udm

Ilvmax=1.05Idm

Ik=Ikngmax=E.Idm/X

Chon BI theo Ilvmax

So do noi BI va Role sao thieu Ksd=1

BVImax:Ikdbv=Kat.Kmm.Ilvmax/Ktv

IkdR=Ikdbv.Ksd/ni

Chon Idr...I'kdbv...Kn=Ikmim/I'kdbv>1.5

Catnhanh:Ikdbv=Kat.Ikngmav Kn>2

Bienap va duong day:

Chon Ucs(k=6.3/22)

Xh=X*.U^2/Sdm Xba=Uk%.U^2dm/100.Sdm

Xdd=Xo.L.k^2 X=Xh+Xba+Xdd

Ik(6.3)=6.3/can3.X Ik(22)=k.Ik(6.3)

Ilvmax=Kqt.Sdm/can3.Udm

Nguon va bienap:

Chon Ucs=10,5 Tinh Xh,Xba

X=Xh+Xba Ik(10.5)=10.5/can3.X

Ik(115)=Ik(10.5).k

Ilvmax=Kqt.Sdm/can3.udm

Kn=0.87Ik(115)/I'kdbv