PROBLEM 2 (30pts]: As seen in the figure 2, the two areas of a 50 Hz power system is connected to each other over a tie-line. There is no spinning reserve in area 1. AREA 1 AREA 2 200 MW Load: 2200 MW Gen: 2000 MW Load: 4000 MW Gen: 4200 MW Fo = 50 Hz dF dt *F, 2H Figure 2. A two area system. If the tie line is switched off (the two areas is disconnected from each other). (a) What will be the dynamic response of areal following disconnection. (b) Find the rate of change of frequency in the AREA 1 following the disconnection. (c) How long does it take to decrease the system frequency down to 49.5 Hz after the dis- connection. The isolated area 1 has an inertia constant of 4 sec based on 2000 MW. (d) Determine the settings of the under frequency relays which will accomplished a load shedding plan to drop 200 MW load in one step in area 1. Assume that tripping delay is 250ms and the safety margin is 0.2Hz. PROBLEM 2 (30pts]: As seen in the figure 2, the two areas of a 50 Hz power system is connected to each other over a tie-line. There is no spinning reserve in area 1. AREA 1 AREA 2 200 MW Load: 2200 MW Gen: 2000 MW Load: 4000 MW Gen: 4200 MW Fo = 50 Hz dF dt *F, 2H Figure 2. A two area system. If the tie line is switched off (the two areas is disconnected from each other). (a) What will be the dynamic response of areal following disconnection. (b) Find the rate of change of frequency in the AREA 1 following the disconnection. (c) How long does it take to decrease the system frequency down to 49.5 Hz after the dis- connection. The isolated area 1 has an inertia constant of 4 sec based on 2000 MW. (d) Determine the settings of the under frequency relays which will accomplished a load shedding plan to drop 200 MW load in one step in area 1. Assume that tripping delay is 250ms and the safety margin is 0.2Hz