1
GATE EE 2003
MCQ (Single Correct Answer)
+2
-0.6
A 20-MVA, 6.6-kV, 3-phase alternator is connected to a 3-phase transmission line. The per unit positive sequence, negative sequence and zero sequence impedance of the alternator are j0.1, and j0.04 respectively. The neutral of the alternator is connected to ground through an inductive reactor of j0.05 p.u. The per unit positive, negative and zero sequence impedances of the transmission line are j0.1 and j0.3 respectively. All per unit values are based on the machine ratings. A solid ground fault occurs at one phase of the far end of the transmission line. The voltage of the alternator neutral with respect to ground during the fault is
A
513.8 V
B
889.9 V
C
1112.0 V
D
642.2 V
2
GATE EE 2003
MCQ (Single Correct Answer)
+1
-0.3
A $$3$$-phase, $$11$$-$$kV$$ generator feeds power to a constant power unity power factor load of $$100$$ $$MW$$ through a $$3$$-phase transmission line. The line-to-line voltage at the terminals of the machine is maintained constant at $$11$$ $$kV$$. The per unit positive sequence impedance of the line based on $$100$$ $$MVA$$ and $$11$$ $$kV$$ is $$j$$ $$0.2$$. The line to line voltage at the load terminals is measured to be less than $$11$$ $$kV$$. The total reactive power to be injected at the terminals of the load to increase the line-to-line voltage at the load terminals to $$11$$ $$kV$$ is
A
$$100$$ MVAR
B
$$10.1$$ MVAR
C
$$-100$$ MVAR
D
$$-10.1$$ MVAR
3
GATE EE 2003
MCQ (Single Correct Answer)
+2
-0.6
A generator delivers power of 1.0 p.u. to an infinite bus through a purely reactive network. The maximum power that could be delivered by the generator is 2.0 p.u. A three-phase fault occurs at the terminals of the generator which reduces the generator output to zero. The fault is cleared after $${t_c}$$ seconds. The original network is then restored. The maximum swing of the rotor angle is found to be $${\delta _{\max }} = 110$$ electrical degree. Then the rotor angle in electrical degrees at $$t = {t_c}$$ is
A
55
B
70
C
69.14
D
72.4
4
GATE EE 2003
MCQ (Single Correct Answer)
+2
-0.6
The ABCD parameters of a $$3$$-phase overhead transmission line are $$\,A = D = 0.9\angle {0^ \circ }.\,\,B = 200\,\angle {90^ \circ }\,\,\Omega \,\,\,$$ and $$\,\,C = 0.95\, \times \,\,{10^{ - 3}}\angle {90^ \circ }\,\,S.\,\,\,\,$$ At no-load condition, a shunt inductive reactor is connected at the receiving end of the line to limit the receiving end voltage to be equal to the sending-end voltage. The ohmic value of the reactor is
A
$$\infty \Omega $$
B
$$2000\,\Omega $$
C
$$105.26\,\Omega $$
D
$$1052.6\,\Omega $$