Year 2023

Week # 2 Quiz 4

Q1. In a power system with negligible resistance, the fault current at a point is 10 p.u. The series reactance to be included at the fault point to limit the short-circuit current to 5 p.u. is

Q2. A transmission line is compensated with shunt capacitance \(C_{sh}\). After shunt compensation surge impedance loading will

Q3. A string type insulator has \(4\) units with self capacitance \(C\) and shunt capacitance of \(0.3 \times C\). Find the string efficiency.

Q4. The surge impedance loading of a 500 km long, 400 KV transmission line is 400 ohms. The SIL(Surge Impedance Loading) is__________.

Q5. A 132 kV transmission line uses strings of insulators, each insulator rated at 25 kV. The string efficiency can be maximum of 60%. The least number of insulators required in a string is

Q6. The units of inertia constant are:

Q7. When a 50MVA ,11KV , 3-phase generator is subjected to a 3-phase fault, the fault current is -j5 p.u.. When it is subjected to line-line fault, the positive sequence current is -j4 p.u.. The positive and negative sequence reactances are respectively

Q8. For a given generator in economic operation mode, the incremental cost is given by \((0.022 P + 12) Rs/MWh, \frac{dP_L}{dP} = 0.18\) and plant panelty factor \(\lambda = 20\), then power generation is

Q9. For the bus admittance matrix \(Y_{bus}\) of a \(4\)-bus system given in per unit, the buses having shunt elements are
\(Y_{bus} = j\begin{bmatrix}-5 & 2 & 2.5 & 0 \\2 & -10 & 2.5 & 4 \\2.5 & 2.5 & -9 & 4 \\0 & 4 & 4 & -8 \end{bmatrix}\)

Q10. Consider a solar PV plant with the following specific conditions: Analysis period: 1 year Measured average solar irradiation intensity in 1 year: 150 kWh/\(m^2\) Generator area of the PV plant: 10 \(m^2\) Efficiency factor of the PV modules: 15% Electrical energy actually exported by plant to grid: 135 kWh Calculate the performance ratio.