1
GATE EE 2017 Set 1
Numerical
+1
-0
A 10-bus power system consists of four generator buses indexed as G1, G2, G3, G4 and six load buses indexed as L1, L2, L3, L4, L5, L6. The generator bus G1 is considered as slack bus, and the load buses L3 and L4 are voltage controlled buses. The generator at bus G2 cannot supply the required reactive power demand, and hence it is operating at its maximum reactive power limit. The number of non-linear equations required for solving the load flow problem using Newton-Raphson method in polar form is ____________.
2
GATE EE 2017 Set 2
+1
-0.3
The figure show the per-phase representation of a phase-shifting transformer connected between buses $$1$$ and $$2,$$ where $$\alpha$$ is a complex number with non-zero real and imaginary parts.
For the given circuit, $${Y_{bus}}$$ and $${Z_{bus}}$$ are bus admittance matrix and bus impedance matrix, respectively, each of size $$2\, \times \,2$$. Which one of the following statements is true?
A
Both $${Y_{bus}}$$ and $${Z_{bus}}$$ are symmetric
B
$${Y_{bus}}$$ is symmetric and $${Z_{bus}}$$ is unsymmetric
C
$${Y_{bus}}$$ is unsymmetric and $${Z_{bus}}$$ is symmetric
D
Both $${Y_{bus}}$$ and $${Z_{bus}}$$ are unsymmetric
3
GATE EE 2017 Set 2
Numerical
+1
-0
In a load flow problem solved by Newton-Raphson method with polar coordinates, the size of the Jacobian is $$\,100\,\, \times \,\,100.$$ If there are $$20$$ PV buses in addition to PQ buses and a slack bus, the total number of buses in the system is ________.
4
GATE EE 2016 Set 1
Numerical
+1
-0
The magnitude of three-phase fault currents at buses A and B of a power system are 10 pu and 8 pu, respectively. Neglect all resistances in the system and consider the pre-fault system to be unloaded. The pre-fault voltage at all buses in the system is 1.0 pu. The voltage magnitude at bus B during a three-phase fault at bus A is 0.8 pu. The voltage magnitude at bus A during a three-phase fault at bus B in pu, is __________.