Year 2024

Week # 2 Quiz 4

Q1. A 3-phase transmission line operating at \(V_s = 400 kV\) and it's \(ABCD\) parameters \(A= D = 0.9∠0°, B = 100∠°90 \Omega, C = 0.6 \times 10^{-6}∠90° \mho\). Calculate the charging current under no load condition.

Q2. In transmission line:

Q3. The zero-sequence network equivalent for the transformer connected between buses 1 and 2 as shown in Fig. is

Q4. In a three phase system, line losses are

Q5. The line currents in amperes in phases a, b and c respectively are 500 +j150, 100 – j600 and – 300 + j600 referred to the same reference vector with phase sequence of 'abc'. Find the symmetrical component of currents.

Q6. In case of interconnected power system, if the input to the prime mover of an alternator is kept constant but the excitation is changed, then the

Q7. A transmission line is compensated with shunt capacitance in such a way, the new surge impedance \(Z_s ^{'}\) will become \(350 \Omega\). The surge impedance of uncompensated line is \(Z_s = 400 \Omega\). Find the degree of shunt compensation.

Q8. Consider the power system network shown in Figure. Generator reactance and terminal voltages are given as: \(X_d^{'}=0.2\) p.u. and \(V_t=1.0\) p.u. Transformer reactance is \(0.1\) p.u. Infinite bus voltage is \(1.0\) p.u. Generator is feeding \(1.0\) p.u power to the infinite bus. Calculate the maximum steady-state power limit that can be transferred when the system is healthy.

Q9. Three generators are connected in parallel whose ratings are as follows: \(G_1: 100 MVA, 12 kV, X_{g1} = 0.1 pu\) \(G_2: 200 MVA, 12 kV, X_{g2} = 0.15 pu\) \(G_3: 150 MVA, 15 kV, X_{g3} = 0.15 pu\) Find the equivalent per unit reactance of the system on 200 MVA, 15 kV system base.

Q10. A loss less transmission line has a length of \(500 km\), find the phase shift of voltage signal.