A 100-MVA, 18-kV generator is connected to a transformer. The generator has reactances of 19%, 26% and 130% and time constraints of Td" = 0.035 sec, Td' = 2.0 sec and TA = 0.2 sec. A 5-cycle breaker is connected between the generator and the transformer. A three=phase short circuit occurs between the breaker and the transformer when the generator is operating at 5% above rated voltage and at no-load. Calculate a. The minimum instantaneous symmetrical fault current which the breaker interrupts (kA) b. The instantaneous asymmetrical fault current (kA) which the breaker interrupts assuming maximum DC offset

A 100-MVA, 18-kV generator is connected to a transformer. The generator has reactances of 19%, 26% and 130% and time constraints of Td" = 0.035 sec, Td' = 2.0 sec and TA = 0.2 sec. A 5-cycle breaker is connected between the generator and the transformer. A three=phase short circuit occurs between the breaker and the transformer when the generator is operating at 5% above rated voltage and at no-load. Calculate a. The minimum instantaneous symmetrical fault current which the breaker interrupts (kA) b. The instantaneous asymmetrical fault current (kA) which the breaker interrupts assuming maximum DC offset

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

Chapter7: Symmetrical Faults

Section: Chapter Questions

Problem 7.6P

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