1. A 120-MVA, 20-kV generator is connected to a transformer. The generator has reactance of 19%, 28%, and 130% and time constants of Ta" = 0.035 sec. Ta' = 2.0 sec and TA= 0.2 sec. It is operating at no load and rated voltage when a three-phase short circuit occurs at the generator terminals. Calculate: A. The initial symmetrical rms fault current in kA. B. The Sustained rms fault current in kA. 2. A 10-cycle breaker is connected between the generator and the transformer in Problem 1. A three- phase short-circuit occurs between the breaker and the transformer when the generator is operating 5% above rated voltage and at no-load. Find the following: A. The maximum instantaneous symmetrical fault current which the breaker interrupts in kA. B. The instantaneous asymmetrical fault current in kA which the breaker interrupts assuming maximum dc offset. NEED ANSWER FOR QUESTION NO.2 ONLY

1. A 120-MVA, 20-kV generator is connected to a transformer. The generator has reactance of 19%, 28%, and 130% and time constants of Ta" = 0.035 sec. Ta' = 2.0 sec and TA= 0.2 sec. It is operating at no load and rated voltage when a three-phase short circuit occurs at the generator terminals. Calculate: A. The initial symmetrical rms fault current in kA. B. The Sustained rms fault current in kA. 2. A 10-cycle breaker is connected between the generator and the transformer in Problem 1. A three- phase short-circuit occurs between the breaker and the transformer when the generator is operating 5% above rated voltage and at no-load. Find the following: A. The maximum instantaneous symmetrical fault current which the breaker interrupts in kA. B. The instantaneous asymmetrical fault current in kA which the breaker interrupts assuming maximum dc offset. NEED ANSWER FOR QUESTION NO.2 ONLY

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

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