ELD within the plant without transmission losses

Q. Incremental fuel costs (in some appropriate unit) for a power plant consisting of three generating units are

$I{C}_1=20+0.3P_1$,
$I{C}_2=30+0.4P_2$,
$I{C}_3=30$

where P${}_i$ is the power in MW generated by units for i = 1, 2 and 3.

Assume that all the three units are operating all the time. Minimum and maximum loads on each units are 50 MW and 300 MW respecitvely. If the plant is operating on economic load dispatch to supply the total power demand of 700 MW, the power generated by each unit is

1. P${}_1$ = 242.86 MW; P${}_2$ = 157.14 MW; and P${}_3$ = 300 MW
2. P${}_1$ = 157.14 MW; P${}_2$ = 242.86 MW; and P${}_3$ = 300 MW
3. P${}_1$ = 300.0 MW; P${}_2$ = 300.0 MW; and P${}_3$ = 100 MW
4. P${}_1$ = 233.3 MW; P${}_2$ = 233.3 MW; and P${}_3$ = 233.4 MW

Q.

Which service design process makes the most use of data supplied by demand management?

Q. The incremental cost curves in Rs/MWhr for two generators supplying a common load of 700 MW are shown in the figures. The maximum and minimum generation limits are also indicated. The optimum generation schedule is:

1. Generator A: 400 MW, Generator B: 300 MW
2. Generator A: 350 MW, Generator B: 350 MW
3. Generator A: 450 MW, Generator B: 250 MW
4. Generator A: 425 MW, Generator B: 275 MW

Q. Consider a power system with three identical generators. The transmission losses are negligible. One generator (G1) has a speed governor which maintains its speed constant at the rated value while the other generators (G2 and G3) have governors with a droops of 5%. If the load of the system is increased, then in steady state.

1. Generation of G2 adn G3 is increased equally while generation of G1 is unchanged.
2. Generation of G1 alone is increased while generation of G2 and G3 is unchanged.
3. Generation of G1, G2 and G3 is increased equally.
4. Generation of G1, G2 and G3 is increased in the ratio 0.5 : 25 : 0.25

Q. Three generators are feeding a load of 100 MW. The details of the generators are

	Rating(MW)	Efficiency (%)	Regulation (pu) on 100 MVA base
Generator-1	100	20	0.02
Generator- 2	100	30	0.04
Generator - 3	100	40	0.03

In the event of increased load power demand, which of the following will happen?

1. All the generators will share equal power
2. Generator-3 will share more power compared to Generator-1
3. Generator-1 will share more power compared to Generator-2
4. Generator-2 will share more power compared to Generator-3

Q. The increment cost curves of three generators are shown, the demand on the system is 240 MW.
For economic load dispatch the generators schedule is

1. $P_1=20MW,P_2=70MW,P_3=150MW$
2. $P_1=20MW,P_2=150MW,P_3=70MW$
3. $P_1=50MW,P_2=50MW,P_3=90MW$
4. $P_1=20MW,P_2=90MW,P_3=130MW$

Q. Out of the following option, the most relevant information needed to specify the real power (P) at the PV buses in a load flow analysis is

1. solution of economic load dispatch
2. base power of the generator
3. rated power output of the generator
4. rated voltage of the generator

Q. The fuel inputs per hour of two generators delivering 200 MW are as follows:
$F_1=20P_1+0.05P_1^2+50$ Rs per hour,
$F_2=16P_2+0.1P_2^2+40$ Rs per hour
The limits of generators are $20\le P_2\le 60MW;$
$40\le P_1\le 150MW$
For economic generation $P_1$ and $P_2$ should be

1. $P_1=120MW,P_2=80MW$
2. $P_1=145MW,P_2=55MW$
3. $P_1=140MW,P_2=60MW$
4. $P_1=100MW,P_2=100MW$