A 12KVA, 1200/400 V, single-phase, 50Hz transformer has the following test results: Open Circuit test (HV side): VI=1200V, 10=1.2A, Po=70 W Short Circuit test (LV side): Vsc=30 v, Isc=22 A, Psc=80 w Find the following: 1). Equivalent resistance of the transformer referred to as LV side.(Req2). 2) Equivalent leakage reactance (Xeq2). 3). Calculate the magnitude secondary voltage JE2| to keep the secondary terminal voltage 400 V at full load and 0.8 power factor lagging. 4). Voltage Regulation of the transformer at full load and 0.8 power factor lagging.in% 5). Efficiency of the transformer in %

A 12KVA, 1200/400 V, single-phase, 50Hz transformer has the following test results: Open Circuit test (HV side): VI=1200V, 10=1.2A, Po=70 W Short Circuit test (LV side): Vsc=30 v, Isc=22 A, Psc=80 w Find the following: 1). Equivalent resistance of the transformer referred to as LV side.(Req2). 2) Equivalent leakage reactance (Xeq2). 3). Calculate the magnitude secondary voltage JE2| to keep the secondary terminal voltage 400 V at full load and 0.8 power factor lagging. 4). Voltage Regulation of the transformer at full load and 0.8 power factor lagging.in% 5). Efficiency of the transformer in %

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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A two-winding single-phase transformer rated 60kVA,240/1200V,60Hz, has an efficiency of 0.96 when operated at rated load, 0.8 power factor lagging. This transformer is to be utilized as a 1440/1200-V step-down autotransformer in a power distribution system. (a) Find the permissible kVA rating of the autotransformer if the winding currents and voltages are not to exceed the ratings as a two-winding transformer. Assume an ideal transformer. (b) Determine the efficiency of the autotransformer with the kVA loading of part (a) and 0.8 power factor leading.
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