3- Calculate the percentage of winding protected for a three phase/ 20 kV alternator against zere impedance earth faults, if the relay operates when the out of balance current in the pilo reaches 0.15A. Assume CT ratio = 900/ 5 A and R earthing = 6 N . %3D %3D

3- Calculate the percentage of winding protected for a three phase/ 20 kV alternator against zere impedance earth faults, if the relay operates when the out of balance current in the pilo reaches 0.15A. Assume CT ratio = 900/ 5 A and R earthing = 6 N . %3D %3D

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 3.62P: Rework Example 3.12 for a+10 tap, providing a 10 increase for the high-voltage winding.

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Concept explainers

Winding and Constructions

Alternating Current (AC) winding is generally of the 3-phase type due to the inherent advantages of the 3-phase machine. Armature coils must be connected to the yield balance (equivalent in magnitude and 2/3 of the series phase difference of the rod) 3-phase electromotive forces (emf). The armature should be divided into step-bands to start with slots around the perimeter.In the construction of AC machines, the frame is used as an external protective shield to protect it from environmental conditions. The frame also serves as the outer perimeter, allowing the interior to be easily placed. The static state section of the devices is the stator winding attached stator.

Question

Q3-
a- Calculate the percentage of winding protected for a three phase/ 20 kV alternator against e
impedance earth faults, if the relay operates when the out of balance current in the pilot wi
reaches 0.15A. Assume CT ratio = 900/5 A and R earthing = 6 2.
%3D
%3D

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