Question

A remote generator transmits energy to a major load/generation via a system shown in the drawing. Assume the generators voltage behind transient reactance to be 1.1pu, the infinite bus voltage to be 1.0 pu and the power transfer to be 0.3 pu during the steady state condition of the network. The line reactance is j0. 5 pu per line and the transient reactance of the generator isj0. 2 pu. The normalised constant of the generator H- 3KWS7KVA A 3 phase short circuit fault occurs at a point which is at one fifth of the lenght of line 1 as shown in the figure. An ensuing dynamic state follows which results in the fault being cleared. Assume that when the fault is cleared one line is lost from the service. Fa Orod Transssin Suostations ine F Synd Oer e teeaa Lne Geewk Line 2 Gen Transfame Power atov ) Plot the power angle characteristics that can be used with the equal area criterion to determine the transient stability of the subsystem... I) Determine the critical clearing angle required to maintain transient stability of the subsystem.

Answer 1

0.5 Jo-2 jo.1 eer joi eee eees D 5 l티-1 nd0-1-10AM F: Reactonce diagran of "ruboystan (re fautt) tue fom the reactauce diagraus mbrgeleon trausfor reactance intermal node aud the ube busat prefanlt, j% Go2+jo1 +)+) tue Tfautt onditiu behreen tue geueralor at 5jo.65 u Jo'Ts mt [티키1이 jo 2 0.5 eer ndo1-P Fa.2: Raactance dtagra of ste uring fanlt the 7fy tue tuter reactante found the llowing stips uring aut 0:3 j01 j0-15 jo 04 joio5 jo.3 50.2 jo' 4-Y braunfermatin ) (ng 0.35+0.3+35X03 =3.275 pu eel jo 35 jo.3 Y A trausformetin 35x9.3

jo 2, Jo 0.5 So-1 ler 11131 pu Vale l:0 pu fa:3 Reactance Aiegren of the fort fault wlsns n Cnditian TLAutance diagrau af the Mm the Aebinpatn ding pt frult cndiHa (fo), the brntir reactauce jo get, we X3(0.140.I +0.5+0-1) = 0.9 Pcharacterstes Pre-fault (S)- IEIl Sind ( Sins 11X1.0 O 65 = 1 6923 Sins D(0) Sin8 3.2 15) EVl duing faultP2(S) X2 (2) 03359 Sin 1XD Sina O.9 P3 (5) ElIVn X3 poat fault 12222 in paser angle charaderishes fra4 the cntical cleanin angle for the ven fout drawn ane The t detemine wed wiel be in and

(b) . pra.fault:R() PCS) A 1-2222 decelerabg anes Accelerating A1 PM port fault: B(S) 8 fult P( Ay4: P-Scharacterstes initial power input, Pn= 0.3 pu O-3 Pna Sn Siu Prmmy 0.1782 Tad 1 = 10. 21 ( O.3 Sin 1-2222 Pmars Sin - 0.2480=14.21 -2.8936 Ta ACceliating nea A or Sitical cleaning ongleju Tos-0.33 59 Sin 8) 33 59(Cr Sr-GasS) 2 0.3 CSr-8) +0,3

pecelvatig ness A may ns- d (2222StnS-0.3)AS 1.22 22 Cos Sur Cas S 2- 0.3 cnitical deaing angle der fr AA2 0.3(8erS) (rder-Cas do) sSur-Cos + 0.3359 1. 2222 > (2111 - 0. 335) s δ.. o.3 CEmas do) +1-2222 Gs as -o.3351 Cos 222 2 Cs2.93 O.3359 Gs 01782) o.3(2.6936-0-1t82)+I2 Gos S= (1-222-6 3351) =0. 79067 Sr 2.4827 rad 142.248