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A three phase, 100 MVA, 25 kV generator has solidly grounded neutral. The positive, negative, and the zero sequence reactances of the generator are 0.2 pu, 0.2 pu, and 0.05 pu, respectively, at the machine base quantities. If a bolted single phase to ground fault occurs at the terminal of the unloaded generator, the fault current in amperes immediately after the fault is _________.
    Correct answer is '15396'. Can you explain this answer?
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    A three phase, 100 MVA, 25 kV generator has solidly grounded neutral. ...
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    A three phase, 100 MVA, 25 kV generator has solidly grounded neutral. ...
    < b="" />Generator Details< />

    - Power rating: 100 MVA
    - Voltage rating: 25 kV
    - Neutral grounding: Solidly grounded

    < b="" />Reactance Values< />

    - Positive sequence reactance: 0.2 pu
    - Negative sequence reactance: 0.2 pu
    - Zero sequence reactance: 0.05 pu

    < b="" />Fault Condition< />

    - Fault type: Bolted single phase to ground fault
    - Generator state: Unloaded

    < b="" />Calculating Fault Current< />

    To calculate the fault current, we need to determine the equivalent impedance seen by the fault.

    < b="" />Positive Sequence Impedance< />

    The positive sequence impedance is given by the positive sequence reactance (X1) multiplied by the base impedance.

    Positive sequence impedance = X1 * base impedance

    = 0.2 pu * 25 kV^2 / 100 MVA

    = 0.005 pu * 625 kVA / 100 MVA

    = 0.03125 kΩ

    < b="" />Negative Sequence Impedance< />

    The negative sequence impedance is given by the negative sequence reactance (X2) multiplied by the base impedance.

    Negative sequence impedance = X2 * base impedance

    = 0.2 pu * 25 kV^2 / 100 MVA

    = 0.005 pu * 625 kVA / 100 MVA

    = 0.03125 kΩ

    < b="" />Zero Sequence Impedance< />

    The zero sequence impedance is given by the zero sequence reactance (X0) multiplied by the base impedance.

    Zero sequence impedance = X0 * base impedance

    = 0.05 pu * 25 kV^2 / 100 MVA

    = 0.0125 pu * 625 kVA / 100 MVA

    = 0.078125 kΩ

    < b="" />Equivalent Impedance< />

    The equivalent impedance seen by the fault is the sum of the positive, negative, and zero sequence impedances.

    Equivalent impedance = Positive sequence impedance + Negative sequence impedance + Zero sequence impedance

    = 0.03125 kΩ + 0.03125 kΩ + 0.078125 kΩ

    = 0.140625 kΩ

    < b="" />Calculating Fault Current< />

    The fault current is given by the voltage divided by the equivalent impedance.

    Fault current = Voltage / Equivalent impedance

    = 25 kV / 0.140625 kΩ

    = 25,000 V / 140.625 Ω

    = 177.4 A

    Therefore, the fault current immediately after the fault is 177.4 Amperes.

    The given answer of 15396 Amperes seems to be incorrect based on the calculations. Please double-check the provided answer.
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    A three phase, 100 MVA, 25 kV generator has solidly grounded neutral. The positive, negative, and the zero sequence reactances of the generator are 0.2 pu, 0.2 pu, and 0.05 pu, respectively, at the machine base quantities. If a bolted single phase to ground fault occurs at the terminal of the unloaded generator, the fault current in amperes immediately after the fault is _________.Correct answer is '15396'. Can you explain this answer?
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    A three phase, 100 MVA, 25 kV generator has solidly grounded neutral. The positive, negative, and the zero sequence reactances of the generator are 0.2 pu, 0.2 pu, and 0.05 pu, respectively, at the machine base quantities. If a bolted single phase to ground fault occurs at the terminal of the unloaded generator, the fault current in amperes immediately after the fault is _________.Correct answer is '15396'. Can you explain this answer? for GATE 2024 is part of GATE preparation. The Question and answers have been prepared according to the GATE exam syllabus. Information about A three phase, 100 MVA, 25 kV generator has solidly grounded neutral. The positive, negative, and the zero sequence reactances of the generator are 0.2 pu, 0.2 pu, and 0.05 pu, respectively, at the machine base quantities. If a bolted single phase to ground fault occurs at the terminal of the unloaded generator, the fault current in amperes immediately after the fault is _________.Correct answer is '15396'. Can you explain this answer? covers all topics & solutions for GATE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A three phase, 100 MVA, 25 kV generator has solidly grounded neutral. The positive, negative, and the zero sequence reactances of the generator are 0.2 pu, 0.2 pu, and 0.05 pu, respectively, at the machine base quantities. If a bolted single phase to ground fault occurs at the terminal of the unloaded generator, the fault current in amperes immediately after the fault is _________.Correct answer is '15396'. Can you explain this answer?.
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