Power Systems
Economic Load Dispatch
Practice questions from Economic Load Dispatch.
3
Total0
Attempted0
Correct0
IncorrectTwo units, rated at 100 MW and 150 MW, are enabled for economic load dispatch. When the overall incremental cost is 10,000 Rs./MWh, the units are dispatched to 50 MW and 80 MW respectively. At an overall incremental cost of , the power output of the units are 80 MW and 92 MW, respectively. The total plant MW-output (without overloading any unit) at an overall incremental cost of is __________ (round off to the nearest integer).
Given: For &
For
Let
For lossless system,
&
On solving,
for &
On solving,
Now, Rs/ MWh,
Since,
Thus,
Total plant Mw -output without overloading any
The incremental cost curves of two generators (Gen A and Gen B) in a plant supplying a common load are shown in the figure. If the incremental cost of supplying the common load is Rs. 7400 per MWh, then the common load in MW is ________ (rounded off to the nearest integer).
Based on equation of straight line
Since we cannot go below minimum value of power
The expressions of fuel cost of two thermal generating units as a function of the respective power generation and are given as:
where is a constant. For a given value of , optimal dispatch requires the total load of to be shared as and . With the load remaining unchanged, the value of is increased by and optimal dispatch is carried out. The changes in and the total cost of generation, in Rs/hour will be as follows:
will decrease and will increase.
Both and will increase.
will increase and will decrease.
Both and will decrease.
If a is increased by 10% the slope of incremental cost of generator 1 increases so for economic load dispatch when IC1=IC2
Pa1 reduces & Pa2 increases
As a increases & Pa1 reduces there is slight change in F1
As Pa2 increases, F2 increase
∴ Overall cost F1 + F2 increases