Weight optimization of a dry type core form transformer by using ...

1066 H. Demir / EEST Part A: Energy Science and Research 29 (2012) 1063-1072
G cu2 =3.10 -5 .δ cu .w 2 . q 2 .L m2 (7)
G feb =3.10 -3 .δ fe .q fe.L s (8)
G fej =3.10 -3 . δ fe .q fej.2(2M+0,8D) (9)
δ cu , δ fe are the specific copper and iron weight respectively. w 1, w 2 are the primary and
secondary turns of the windings respectively. L m1 (cm), L m2 (cm) are the average length of the
primary and secondary windings respectively. q 1 (mm 2 ),q 2 (mm 2 ), q fe (cm 2 ), q fej (cm 2 ) are the
primary winding cross section, secondary winding cross section, iron cross section from the
leg and the iron cross section from the upper-lower part of the core where;
q fe=C.
10 3 S
(10)
3f
q fej=1,1. q fe (11)
q 1 = s
I 1
(12)
I
q 2 = 2
(13)
s
U
1
w 1 =
8
3.4,44.f. .10
U
2
w 2 =
8
3.4,44.f. .10
(14)
(15)
L m1= π.D m1 (16)
L m2= π.D m2 (17)
D m2 =D+2(Δ 2 +δ 2 )+a 2 (18)
D m1 =D m2 +a 2 +2(Δ 1 +δ 1 )+a 1 (19)
D m1 (cm), D m2 (cm) are the average cross section of the primary and secondary windings
respectively. U 1, U 2 (V) is the primary and secondary voltage respectively and f is the
frequency.
Fig. 2. Dry type core form transformer core