A load center of 120 MW derives power from two power stations connected by 220 kV transmission lines of 25 km and 75 km as shown in the figure below. The three generators G1, G2 and G3 are of 100 MW capacity each and have identical fuel cost characteristics. The minimum loss generation schedule for supplying the 120 MW load is?
For minimum loss, higher power should come from a shorter distance transmission line connected to the generator.
Since the load center receives power from two transmission lines of 25 km and 75 km, it is desirable to allocate the maximum power from G1, which is connected to the shorter 25 km line.
Therefore, to minimize the transmission loss, the generation of G1 should be maximized, while the generation of G2 and G3 should be equal and minimized. This results in the minimum loss generation schedule of:
P1 = 90 MW, P2 = 15 MW, and P3 = 15 MW.