.webp "Principles of Power Systems (V.K. Mehta) Solution Manual: Chapter 03")
TUTORIAL PROBLEMS
generated being 60 × 106. Calculate (i) the demand factor (ii) the load factor. [(i) 0·5 (ii) 34·25%]
2. A 100 MW powers stations delivers 100
MW for 2 hours, 50 MW for 8 hours and is shut down for the
rest of each day. It is also shut down for maintenance
for 60 days each year. Calculate its annual load
factor. [21%]
3. A power station is to supply four
regions of loads whose peak values are 10,000 kW, 5000 kW, 8000 kW
and 7000 kW. The diversity factor of the load at the
station is 1.5 and the average annual load factor is
60%. Calculate the maximum demand on the station and
annual energy supplied from the station.
[20,000
kW; 105·12 × 106 kWh]
4. A generating station supplies the
following loads: 15000 kW, 12000 kW, 8500 kW, 6000 kW and 450
kW. The station has a maximum demand of 22000 kW. The
annual load factor of the station is 48%.
Calculate (i) the number
of units supplied annually (ii) the
diversity factor and (iii) the demand
factor.
[(i) 925 ×
105 kWh (ii) 52·4% (iii) 1·9]
5. A generating station has a maximum
demand of 20 MW, a load factor of 60%, a plant capacity factor of
48% and a plant use factor of 80%. Find:
(i) the daily
energy produced
(ii) the reserve
capacity of the plant
(iii) the maximum energy that could be produced daily if the plant was running all the time
(iv) the maximum energy that could be produced daily if the plant was running fully loaded and operating as per schedule. [(i) 288 × 103 kWh (ii) 0 (iii) 4·80 × 103 kWh (iv) 600 × 103 kWh]
6. A generating station has the following daily load cycle :
Time (hours) 0—6 6—10 10—12 12—16 16—20 20—24
Load (MW) 20 25 30 25 35 20
Draw the load curve and find
(i) maximum demand,
(ii) units generated per day,
(iii) average load,
(iv) load factor, [(i) 35 MW
(ii) 560 × 103 kWh (iii) 23333
kW (iv) 66·67%]
7. A power station has to meet the following load demand:
Load A 50 kW between 10 A.M. and 6 P.M.
Load B 30 kW between 6 P.M. and 10 P.M.
Load C 20 kW between 4 P.M. and 10 A.M.
Plot the daily load curve and determine (i)
diversity factor (ii) units generated per day (iii) load
factor.
[(i) 1·43 (ii) 880
kWh (iii) 52·38%]
8. A substation supplies power by four feeders to its consumers.
Feeder no. 1 supplies six consumers
whose individual daily maximum demands are 70 kW, 90 kW, 20 kW, 50 kW, 10 kW
and 20 kW while
the maximum demand on the feeder is 200 kW. Feeder no. 2 supplies four
consumers whose daily
maximum demands are 60 kW, 40 kW, 70 kW and 30 kW, while the maximum demand on
the feeder is
160 kW. Feeder nos. 3 and 4 have a daily maximum demand of 150 kW and 200 kW
respectively while
the maximum demand on the station is 600 kW.
Determine the diversity factors for feeder no. 1. feeder no. 2 and for the four
feeders. [1·3, 1·25, 1·183]
9. A central station is supplying energy to a community through two
substations. Each substation feeds
four feeders. The maximum daily recorded demands are:
POWER STATION........ 12,000 KW
Substation A ...... 6000 kW Sub-station B ....
9000 kW
Feeder 1 ............ 1700 kW Feeder 1 ............ 2820 kW
Feeder 2 ............ 1800 kW Feeder 2 ............ 1500 kW
Feeder 3 ............ 2800 kW Feeder 3 ............ 4000 kW
Feeder 4 ............ 600 kW Feeder 4 ............ 2900 kW
Calculate the diversity factor between (i)
substations (ii) feeders on substation A and (iii)
feeders on sub
Calculate the diversity factor between (i)
substations (ii) feeders on substation A and (iii)
feeders on sub
|
station B. |
[(i)
1·25 (ii) 1·15 (iii)
1·24] |
|
10. The yearly load duration curve of a certain power station can
be approximated as a straight line; the |
|
maximum and minimum loads being 80 MW and 40 MW respectively.
To meet this load, three turbine |
|
generator units, two rated at 20 MW each and one at 10 MW are
installed. Determine (i) installed |
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capacity (ii) plant factor (iii) kWh
output per year (iv) load factor. |
[(i) 50MW (ii) 48% (iii) 210 × 106 (iv) 60%]
