Lecture-16 OUTPUT EQUATIONS a. Single phase core type transformer φm Rating of the transformer in kVA = V1I1 x = E1I1 x = 4.44 f T1 x I1 x 10-3 10-3 10-3 …. (1) H L L H L H H L V V V V V V V V a1 a2 Note: Each leg carries half of the LV and HV turns 2 I1T1 I2T2 I1T1 Area of copper in the window Acu = a1T1 + = a2T2 AwKw = + = δ δ δ Therefore I1T1 = ……… (2) 2 4.44 AiBmf x After substituting (2) in (1), kVA = AwKwδ x 10-3 2 = 2.22 fδ AiBm AwKw x 10-3 b. Single phase shell type transformer HV LV LV HV Rating of the transformer in kVA = V1I1 x = E1I1 x 10-3 φm = 4.44 f T1 x I1 x 10-3 …(1) a1 a2 [ Note : Since there are two windows, it is sufficient to design one of the two windows as both the windows are symmetrical. Since the LV and HV windings are placed on the central leg, each window accommodates T1 and T2 turns of both primary and secondary windings.] I1 I2 2 I1 Area of copper in the window Aw = a1T1 +  Aw T1 T2 T2 a2T2   = Kw δ δ δ
Lecture-16 OUTPUT EQUATIONS a. Single phase core type transformer Rating of the transformer in kVA = V1I1 x 10-3 = E1I1 x 10-3 = 4.44 φm f T1 x I1 x 10-3 …. (1) H L L H H L L H V V V V V V V V a1 a2 Note: Each leg carries half of the LV and HV turns I1T1 I2T2 2 I1T1 Area of copper in the window Acu = a1T1 + a2T2 = + = = AwKw δ δ δ Therefore I1T1 = ……… (2) 2 After substituting (2) in (1), kVA = 4.44 AiBmf x AwKwδ x 10-3 2 = 2.22 fδ AiBm AwKw x 10-3 b. Single phase shell type transformer Rating of the transformer in kVA = V1I1 x HV LV LV HV = E1I1 x 10-3 = 4.44 φm f T1 x I1 x 10-3 …(1) a1 a2 [ Note : Since there are two windows, it is sufficient to design one of the two windows as both the windows are symmetrical. Since the LV and HV windings are placed on the central leg, each window accommodates T1 and T2 turns of both primary and secondary windings.] Area of copper in the window Aw = a1T1 + a2T2 = I1 T1  I2 T2  2 I1 T2  Aw Kw δ δ δ