10.2 Using the values of R and D in each area, for Example 10B, resolve for the 100-MW load change in area 1 under the following conditions: Area 1: base MVA = 2000 MVA Area 2: base MVA = 500 MVA Then solve for a load change of 100 MW occurring in area 2 with R values and D values as in Example 10B and base MVA for each area as before. Example 10B: You are given two system areas connected by a tie line with the following characteristics: Area 1 Area 2 R=0,01 pu D=0.8 pu Base MVA = 500 R-0.02 pu D=1.0 pu Base MVA = 500

Q5/ A three bus power system is shown in Figure (3) The system parameters are given in Tables below. The voltage at bus 2 is maintained at 1.03p.u. The maximum and minimum reactive power limits of the generation at bus 2 are 35 and 0 Mvar respectively. Taking bus 1 as slack bus, obtain the load flow solution using NR iterative method. Zitration Speloomu Vz= 1.3 P=50 MW S2=? Q2020 a S. 435 P.3. Bus Impedance (p.u) 1-2 j0.24 1V31=2 S3 =? 1-3 j0.06 Q3:35 2-3 J0.018 Bus voltage generation load MW Mvar MW Mvar 1 1.05+j 0.0 0 0 ad 2 1.03+j 0.0 30 P 50 20 3 0 ********** Q350 60D 25

Description In the particular case of figure below derive both the critical clearing angle and the critical clearing time. P, = Pmaz sin d Pm A1 do der Smar A generator having H = 6.R MJ/MVA is delivering power of 1.0 per unit to an infinite bus through a purely reactive network when the occurrence of a fault reduces the generator output power to zero. The maximum power that could be delivered is 2.5S per unit. When the fault is cleared, the original network conditions again exist. Determine the critical clearing angle and critical clearing time. (Roll=PQRS)

Q2) The bus-bar (A) and (B) are linked by a bus-bar reactor of 1000 KVA with 10% reactance on bus-bar (A). The system has 2 generators each one of 5000 KVA with 5 % reactance, and on bus-bar (B) two motors each one of 5000 KVA with 12% reactance. Find the steady state apparent power (MVA) given to the symmetrical short circuit occurred on bus-bar (B) in the circuit shown below. Ма Mi B Gi A G₂ Xr m