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In the system shown in Figure 1, the transformers are connected star-star with both star points grounded and the generators are connected in star with thier star points grounded. The system base is {SBASE} MVA. The transformers all have reactances of {Tpu} p.u. on this {SBASE} MVA base. The reactances of all other elements are given in Table 1 (in $\\Omega$) and the voltage levels are given in Table 2.

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{image('resources/question-resources/FA5Bus.png')}

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Figure 1: A section of the distribution system

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\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
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G1

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L

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G2

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X

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{G1}

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{L}

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{G2}

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 Table 1: Sequence reactances ($\\Omega$)

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\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
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G1

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T1

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L

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T2

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G2

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T3

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BASE

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{VG1}

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{VG1}/{VL}

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{VL}

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{VL}/{VG2}

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{VG2}

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{VL}/{V3}

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Table 2: Voltage bases (kV)

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Convert all values to p.u. on a {SBASE} MVA base.

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$ X_{G1} $ = [[0]] p.u.

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$ X_{G2} $ = [[1]] p.u.

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$X_L $ = [[2]] p.u.

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A three-phase fault with a fault reactance of {XFpu} p.u. occurs at bus 3. Calculate the fault current flowing at the fault point in kA.

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$ I_F $ = -j [[0]]  kA

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What is the voltage at bus 3 (in Volts) after the fault has occurred?

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$V_F$ = [[0]] V

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