Question 3 H A two-winding transformer rated at P = 90 kVA, V₁ /Vµ = 240/1200 V, ƒ = 60 Hz. When this two-winding transformer operates at rated load and power factor pf 0.8, its efficiency is 90%. (1) Calculate the primary currents on the low-voltage side ILv and high-voltage side Ìµv. = (2) The above transformer is to be connected as an autotransformer, i) calculate the secondary current Isecondary of the autotransformer; ii) draw the relevant diagram and label all relevant currents and voltages if this transformer is to be used as a 1440/1200 V step-down autotransformer in a power distribution system. (3) Calculate the transformer kVA rating when used as an autotransformer. (For this part assume an ideal transformer.)

Question 3 H A two-winding transformer rated at P = 90 kVA, V₁ /Vµ = 240/1200 V, ƒ = 60 Hz. When this two-winding transformer operates at rated load and power factor pf 0.8, its efficiency is 90%. (1) Calculate the primary currents on the low-voltage side ILv and high-voltage side Ìµv. = (2) The above transformer is to be connected as an autotransformer, i) calculate the secondary current Isecondary of the autotransformer; ii) draw the relevant diagram and label all relevant currents and voltages if this transformer is to be used as a 1440/1200 V step-down autotransformer in a power distribution system. (3) Calculate the transformer kVA rating when used as an autotransformer. (For this part assume an ideal transformer.)

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.9P

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