Power System-III 2018 Question Paper — Government College of Engineer…

The 2018 Power System-III previous year question paper (Government College of Engineering and Technology, Jammu), with every question and its marks.

Instructions

Attempt five questions in all selecting at least two questions from each Section.
Each question carries 20 marks.
Use of calculator is allowed.

QQues1. a) What is the significance of load flow study? Also discuss the importance of acceleration factor. (10) b) Why Y-bus is used for load flow studies? Write its properties? (10) [20 marks]
QQues2. a) Form y-bus for the 4-bus system as given in the table Line (bus to bus) | Impedance 1-2 | $0.15 + j0.6$ pu 1-3 | $0.1 + j0.4$ pu 1-4 | $0.15 + j0.6$ pu 2-3 | $0.05 + j0.2$ pu 3-4 | $0.05 + j0.2$ pu (10) b) Obtain the z-bus by building procedure (10) p-q (nodes) | impedance 0-1 | 0.25 0-2 | 0.20 1-2 | 0.08 2-3 | 0.06 [20 marks]
QQues3. For the network shown in fig obtain the complex bus bar voltage at bus 2 at the end of the first iteration using gauss-siedel method. Line impedance are (20) Given Bus 1 is slack bus with $V_1 = 1.0\angle 0^\circ$, $P_2 + jQ_2 = -5.96 + j1.46$, $|V_3| = 1.02$ pu Assume $V_3 = 1.02\angle 0^\circ$ and $V_2 = 1.0\angle 0^\circ$ [20 marks]
QQues4. Write the algorithm for load flow solution using Newton-Raphson method. Also draw its flow chart (20) [20 marks]

QQues5. How equal area criterion is used for the power system stability? Write its applications. (20) [20 marks]
QQues6. a) Write the expression for the numerical solution of swing equation. (10) b) Distinguish between steady state stability, transient stability and dynamic stability. (10) [20 marks]
QQues7. a) Write short note on optimum power flow? (10) b) Derive the expression for representation of transmission loss by $\beta$-coefficient. (10) [20 marks]
QQues8. a) A power consist of two 200 MW units, whose input cost is given by (12) $F_1 = 0.004\,P_1^2 + 2.0\,P_1 + 80$ $F_2 = 0.006\,P_2^2 + 1.5\,P_2 + 100$ For the total load of 250 MW What should be the division of load between two units of most economic operation? b) What do you mean by unit commitment? (8) [20 marks]