5. A 13.8 kV/480 V three-phase Y-A transformer bank consists of three identical 100 kVA, 7967 V/480 V single-phase transformers. It is supplied with power directly from a large constant voltage bus. In the short-circuit test, the recorded values on the HV side are Vsc 560 V, Isc = 12.6 A, Psc = = 3300 W 2 a) If this bank delivers a rated load at 0.88 PF lagging and rated voltage, what is the line-to-line voltage on the primary of the transformer bank? b) What is the voltage regulation under these conditions? V p Load Y A

5. A 13.8 kV/480 V three-phase Y-A transformer bank consists of three identical 100 kVA, 7967 V/480 V single-phase transformers. It is supplied with power directly from a large constant voltage bus. In the short-circuit test, the recorded values on the HV side are Vsc 560 V, Isc = 12.6 A, Psc = = 3300 W 2 a) If this bank delivers a rated load at 0.88 PF lagging and rated voltage, what is the line-to-line voltage on the primary of the transformer bank? b) What is the voltage regulation under these conditions? V p Load Y A

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 3.10P: A single-phase step-down transformer is rated 13MVA,66kV/11.5kV. With the 11.5 kV winding...

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In per-unit equivalent circuits of practical three-phase transformers, under balanced thr-phase operation, in which of the following connect ions would a phase-shifting transformer come up? (a) Y-Y (b) Y- (c) -
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Ql-phase step down transformer 1250 KVA, 1 1000/2200 V, 50 Hz .The resistance /phase and leakage reactance phase of the primary winding are 0.78 N and 4.82 and the corresponding values for the secondary winding are 0.012 and 0.000 respectively if the primary winding is connected in delta and secondary in star calculate: )The voltage to be applied at normal frequency to the primary to circulate full-load through it when the secondary is short-circuited Ii) The full load copper loss
Tutorial 1.7 The three-phase ratings of a three-winding transformer are: Primary Y-connected, 66 kV, 24 MVA Y-connected, 13.2 kV, 12 MVA Secondary Tertiary A-connected, 2.3 kV, 4 MVA Neglecting resistance, the leakage impedances are: Zps Zns = 6% on 24 MVA, 66 kV base Zpt = 8% on 24 MVA, 66 kV base Zst = 7% on 12 MVA, 13.2 kV base Find the per-unit impedances of the per-phase equivalent circuit for a base of 24 MVA, 66 kV in the primary circuit. {Ans: j 0.0; j 0.06; j 0.08}