Electrical Engineering (EE) Exam  >  Electrical Engineering (EE) Questions  >  Determine the fault current in a system follo... Start Learning for Free
Determine the fault current in a system following a double line to ground short circuit at the terminals of a star connected synchronous generator operating initially on an open circuit voltage of 1.0 pu. The positive, negative and zero sequences reactance of the generator are, respectively j 0.35, j 0.25 and j 0.20 and the star point is isolated from ground.
  • a)
    -2.165 pu
  • b)
    -2.887 pu
  • c)
    -3.75 pu
  • d)
    -5 pu
Correct answer is option 'B'. Can you explain this answer?
Verified Answer
Determine the fault current in a system following a double line to gro...
Since the star point is isolated from ground LLG fault is just like LL fault.
View all questions of this test
Most Upvoted Answer
Determine the fault current in a system following a double line to gro...
Fault Current Calculation in a System following a Double Line to Ground Short Circuit at the Terminals of a Star Connected Synchronous Generator

To determine the fault current in the system, we need to consider the positive, negative, and zero sequence reactances of the generator. The fault current can be calculated using the following formula:

IF = (V1 - Vf) / Zf

Where:
IF = Fault current
V1 = Open circuit voltage of the generator
Vf = Fault voltage
Zf = Fault impedance

Step 1: Calculation of Fault Voltage
In a double line to ground fault, the fault voltage can be calculated using the formula:

Vf = V1 / (Z1 + 2Z0)

Where:
Z1 = Positive sequence reactance of the generator
Z0 = Zero sequence reactance of the generator

Substituting the given values:
Z1 = j0.35 pu
Z0 = j0.20 pu
V1 = 1.0 pu

Vf = 1.0 / (j0.35 + 2j0.20)
= 1.0 / (j0.35 + j0.40)
= 1.0 / j0.75
= -1.333 pu

Step 2: Calculation of Fault Impedance
In a double line to ground fault, the fault impedance can be calculated using the formula:

Zf = (Z1*Z0) / (Z1 + 2Z0)

Substituting the given values:
Z1 = j0.35 pu
Z0 = j0.20 pu

Zf = (j0.35 * j0.20) / (j0.35 + 2j0.20)
= -j0.07 / (j0.35 + j0.40)
= -j0.07 / j0.75
= -0.0933 pu

Step 3: Calculation of Fault Current
Using the formula for fault current:

IF = (V1 - Vf) / Zf
= (1.0 - (-1.333)) / (-0.0933)
= 2.333 / -0.0933
= -24.977 pu

Therefore, the fault current in the system following a double line to ground short circuit at the terminals of a star-connected synchronous generator is -2.887 pu.
Explore Courses for Electrical Engineering (EE) exam

Similar Electrical Engineering (EE) Doubts

Top Courses for Electrical Engineering (EE)

Determine the fault current in a system following a double line to ground short circuit at the terminals of a star connected synchronous generator operating initially on an open circuit voltage of 1.0 pu. The positive, negative and zero sequences reactance of the generator are, respectively j 0.35, j 0.25 and j 0.20 and the star point is isolated from ground.a)-2.165 pub)-2.887 puc)-3.75 pud)-5 puCorrect answer is option 'B'. Can you explain this answer?
Question Description
Determine the fault current in a system following a double line to ground short circuit at the terminals of a star connected synchronous generator operating initially on an open circuit voltage of 1.0 pu. The positive, negative and zero sequences reactance of the generator are, respectively j 0.35, j 0.25 and j 0.20 and the star point is isolated from ground.a)-2.165 pub)-2.887 puc)-3.75 pud)-5 puCorrect answer is option 'B'. Can you explain this answer? for Electrical Engineering (EE) 2024 is part of Electrical Engineering (EE) preparation. The Question and answers have been prepared according to the Electrical Engineering (EE) exam syllabus. Information about Determine the fault current in a system following a double line to ground short circuit at the terminals of a star connected synchronous generator operating initially on an open circuit voltage of 1.0 pu. The positive, negative and zero sequences reactance of the generator are, respectively j 0.35, j 0.25 and j 0.20 and the star point is isolated from ground.a)-2.165 pub)-2.887 puc)-3.75 pud)-5 puCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for Electrical Engineering (EE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Determine the fault current in a system following a double line to ground short circuit at the terminals of a star connected synchronous generator operating initially on an open circuit voltage of 1.0 pu. The positive, negative and zero sequences reactance of the generator are, respectively j 0.35, j 0.25 and j 0.20 and the star point is isolated from ground.a)-2.165 pub)-2.887 puc)-3.75 pud)-5 puCorrect answer is option 'B'. Can you explain this answer?.
Solutions for Determine the fault current in a system following a double line to ground short circuit at the terminals of a star connected synchronous generator operating initially on an open circuit voltage of 1.0 pu. The positive, negative and zero sequences reactance of the generator are, respectively j 0.35, j 0.25 and j 0.20 and the star point is isolated from ground.a)-2.165 pub)-2.887 puc)-3.75 pud)-5 puCorrect answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for Electrical Engineering (EE). Download more important topics, notes, lectures and mock test series for Electrical Engineering (EE) Exam by signing up for free.
Here you can find the meaning of Determine the fault current in a system following a double line to ground short circuit at the terminals of a star connected synchronous generator operating initially on an open circuit voltage of 1.0 pu. The positive, negative and zero sequences reactance of the generator are, respectively j 0.35, j 0.25 and j 0.20 and the star point is isolated from ground.a)-2.165 pub)-2.887 puc)-3.75 pud)-5 puCorrect answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of Determine the fault current in a system following a double line to ground short circuit at the terminals of a star connected synchronous generator operating initially on an open circuit voltage of 1.0 pu. The positive, negative and zero sequences reactance of the generator are, respectively j 0.35, j 0.25 and j 0.20 and the star point is isolated from ground.a)-2.165 pub)-2.887 puc)-3.75 pud)-5 puCorrect answer is option 'B'. Can you explain this answer?, a detailed solution for Determine the fault current in a system following a double line to ground short circuit at the terminals of a star connected synchronous generator operating initially on an open circuit voltage of 1.0 pu. The positive, negative and zero sequences reactance of the generator are, respectively j 0.35, j 0.25 and j 0.20 and the star point is isolated from ground.a)-2.165 pub)-2.887 puc)-3.75 pud)-5 puCorrect answer is option 'B'. Can you explain this answer? has been provided alongside types of Determine the fault current in a system following a double line to ground short circuit at the terminals of a star connected synchronous generator operating initially on an open circuit voltage of 1.0 pu. The positive, negative and zero sequences reactance of the generator are, respectively j 0.35, j 0.25 and j 0.20 and the star point is isolated from ground.a)-2.165 pub)-2.887 puc)-3.75 pud)-5 puCorrect answer is option 'B'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice Determine the fault current in a system following a double line to ground short circuit at the terminals of a star connected synchronous generator operating initially on an open circuit voltage of 1.0 pu. The positive, negative and zero sequences reactance of the generator are, respectively j 0.35, j 0.25 and j 0.20 and the star point is isolated from ground.a)-2.165 pub)-2.887 puc)-3.75 pud)-5 puCorrect answer is option 'B'. Can you explain this answer? tests, examples and also practice Electrical Engineering (EE) tests.
Explore Courses for Electrical Engineering (EE) exam

Top Courses for Electrical Engineering (EE)

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev