Biju Patnaik University of Technology 2008-7th Sem B.Tech Power System Operation & Control - Question Paper
Total number of printed pages-7 B. Tech
CPEE 5401
Seventh Semester Examination - 2008 POWER SYSTEM OPERATION AND CONTROL Full Marks - 70
Time : 3 Hours
Answer Question No. 1 which is compuSsoty and any five from the rest
_ The figures in the nght-hand margin indicate msrks.
1. Answer the following questions : 2 *10
(i) What is meant by 'compact storage scheme11 in load flow analysis ?
(j|) What is meant by terms Jacobian ?
(iii) Why a direct solution of load flow is not possible ?
P.T.O.
(iv) Why a majority of buses in power systems are load buses ?
(v) Differentiate between stability and loss of synchronous,
(vi) What is transfer reactance ?
(vii) A power system network consists of three elements 0-1, 1-2 and 2-0 of per unit impedances 0.2, 0,4, and 0.4 respectively. What is its bus impedance matrix?
(vtiij Principle of Equai-area criterion is to be applied to determine, for a given initial
load P., the maximum amount of sudden
i *
increase in load a P, to maintain transient stability of a cylindrical rotor synchro-nous motor operating from an infinite bus. Applying this criterion (in each case the area A1 - area A2), draw the correct diagram.
CPEE 5401 a Conld.
(ix) With 100% inductive shunt compensation the voltage profile will be flat for what percentage loading of line Briefly explain your answer
(x) What are the effects of series capacitance compensation ?
(a) Analytically establish the role of reactive power on receiving end voltage and voltage regulation of the bad bus. 4
(b) What is reactive compensation and what are the benefits 7 2
(c) Describe different types of reactive power compensation in brief 4
(a) Give a flow chart for a load flow study on a power system having only P-Q buses using G*S method. How does the flow chart get modified to account for PV buses ? 4
(b) Fig. 1 shows a five bus power system. Each line has an impedance of
5EE 5401 3 P.T.O.
0.05 +-j0.15pu The line shun! admittances may be neglected. The bus power and voltage specifications are given below :
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(i) Form Y DUS |
CPEE 5401
Contd.
(ii] Find Q?l V4 and after the first
iteration using Gauss-Seidel method. Assume 0 = 0 2 pu and Q =0.6 pit,
6
(a) Distinguish between steady state, transient and1 dynamic stability Derive power angle equation. 5
(b) Using equal area criterion, derive an expression for critical clearing angle for a system having a generator feeding a large system through a double circuit line 5
A 50 HZ generator of reactance 0 8 pu is connected to an infinite bus through a line of
0 4 pu reactance E = 1.05 pu, V = 10 pu The inertia constant is 4 MJ.'MVA The generator is loaded to 70% of the maximum power limit Find the frequency of natural oscillations Derive the formula used 0
6. A single area consists of two generating units, rated at 400 and 800 MVA, with speed regulation of 4% and 5% on their respective ratings. The units are operating in parallel, sharing 700 MW. Unit 1 supplies 200 MW and unit 2 supplies 500 MW at 1.0 per unit (60 Hz) frequency. The load is increased by 130 MW.
10
(a) Assume there is no frequency dependent i load, i.e., D = 0. Find the steady-state frequency deviation and the new generation on egch unit.
(b) The load varies 0.804 percent for every
1 percent change in frequency, i.e.,
D = 0.804. Find the steady state frequency deviation and the new generation on each unit.
On a system consisting of two generating "plants the incremental costs in rupees per megawatt-hour with P1 and P2 in megawatts are
dR dF,
= O.OOP, + 8.0 and p- = 0.012P + 9.0 dP1 1 dP2 2
The system is operating on economic dispatch with P1 = P2 = 500 MW and sP/gP 0.2. Find the penalty factor of plant 1. 10
Write short note on : 5*2
(a) Methods of improvement of transient stability.
(b) Economic dispatch controller.
PEE 5401 7 -C
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| Earning: Approval pending. |
