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F192049 Pages:2

i) Direct solution of load flow problem is not possible.

ii) Bus admittance matrix is sparse matrix.
A 100MVA synchronous generator operates on full load at frequency of 50 Hz. The
load is suddenly reduced by 50 MW. Due to time lag in governor system, the steam
valve begins to close after 0.4 s. Determine the change in frequency that occurs in this

time. Given H= 5kW-s/kVA.

Draw the block diagram representation of Load Frequency Control (LFC) of a single

area system & explain the steady state stability for free governor operation (AP, = 0)

PART D

Answer any two full questions, each carries 10 marks.
A two bus system is shown in figure below. If a load of 125MW is transmitted from
plant 1 to the load, a loss of 15.625MW is incurred. Determine the generation schedule
and the load demand if the cost of received power 15 Rs.24/MWhr. Solve the problem
using coordination equations and the penalty factor method. The incremental
production costs of the plants are:
dF \/ dP; = 0.025P; + 5
07/60, = 0.05P2+ 20

3 ‏رت‎ पि ऽ ೫2

Load

Distinguish between economic dispatch and unit commitment.
Explain the method of solving swing equation by point-by-point method.
Using equal area criterion, derive an expression for critical clearing angle for a system

having a generator feeding an infinite bus through a single circuit line.

मैप मैप मर मर

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