The functions of two power plants, of a lossless system, are as follows:

a. Write the LaGrange function
b. Write KKT conditions
c. Assume that the demand is PD. Express the incremental cost of the system as a function of PD when economic dispatch is optimal.
d. Assume that the demand is PD. Express the incremental cost of the system as a function of PD when economic dispatch is optimal, and when unit 2 operates at the maximum limit.
 

F (P) = C = 900 +45P + 0.01P F (P) = C: = 2500+ 43P +0.003P [$/h] [$/h] 50 P 200 MW 50 P 600 MW