transformers and VA) connectéd in parallel as shown in the following figure. %Z1=2% ST1 Zeq1 SL1 SL2 Load Zeq2 SLmax=?? KVA ST2 %Z2=3% PF=0.8 lag 1) Assuming that maximum loading of each transformer is 90% and that TRI is loaded first, calculate the loading SLI and SL2 on TRI and TR2 respectively then calculate the maximum V1n

transformers and VA) connectéd in parallel as shown in the following figure. %Z1=2% ST1 Zeq1 SL1 SL2 Load Zeq2 SLmax=?? KVA ST2 %Z2=3% PF=0.8 lag 1) Assuming that maximum loading of each transformer is 90% and that TRI is loaded first, calculate the loading SLI and SL2 on TRI and TR2 respectively then calculate the maximum V1n

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 3.26P: A bank of three single-phase transformers, each rated 30MVA,38.1/3.81kV, are connected in Y- with a...

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An ideal transformer has no real or reactive power loss. (a) True (b) False
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The ideal transformer windings are eliminated from the per-unit equivalent circuit of a transformer. (a) True (b) False
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A bank of three single-phase transformers, each rated 30MVA,38.1/3.81kV, are connected in Y- with a balanced load of three 1, Y-connected resistors. Choosing a base of 90MVA,66kV for the high-voltage side of the three-phase transformer. spify the base for the low-voltage side. Compute the per-unit resistance of the load on the base for the low-voltage side. Also, determine the load resistance in ohms referred to the high-voltage side and the per-unit value on the chosen base.
A single-phase, 50-kVA,2400/240-V,60-Hz distribution transformer has the following parameters: Resistance of the 2400-V winding: R1=0.75 Resistance of the 240-V winding: R2=0.0075 Leakage reactance of the 2400-V winding: X1=1.0 Leakage reactance of the 240-V winding: X2=0.01 Exciting admittance on the 240-V side =0.003j0.02S (a) Draw the equivalent circuit referred to the high-voltage side of the transformer. (b) Draw the equivalent circuit referred to the low-voltage side of the transformer. Show the numerical values of impedances on the equivalent circuits.
Rework Problem 3.14 if the transformer is delivering rated load at rated secondary voltage and at (a) unity power factor, (b) 0.8 power factor leading. Compare the results with those of Problem 3.14. -
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The direct electrical connection of the windings allows transient over voltages to pass through the auto transfonner more easily, and that is an important disadvantage of the autotransformer. (a) True (b) False