A network is composed of the utility having Ssc=500MVA, and an 800KVA transformer, rated at 20KV/410V (no load), whose voltage impedance is 5%, and whose load losses are 5400watts. the short circuit at the secondary of the transformer using the impedance method is: Select one: a)30.5KA b)None of these c)45.8KA d)21.83KA

A network is composed of the utility having Ssc=500MVA, and an 800KVA transformer, rated at 20KV/410V (no load), whose voltage impedance is 5%, and whose load losses are 5400watts. the short circuit at the secondary of the transformer using the impedance method is: Select one: a)30.5KA b)None of these c)45.8KA d)21.83KA

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 3.3P: Consider an ideal transformer with N1=3000andN2=1000 turns. Let winding 1 be connected to a source...

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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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Consider an ideal transformer with N1=3000andN2=1000 turns. Let winding 1 be connected to a source whose voltage is e1(t)=100(1| t |)volts for 1t1ande1(t)=0 for | t |1 second. A2- farad capacitor is connected across winding 2. Sketch e1(t),e2(t),i1(t),andi2(t) versus time t.
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