diff options
Diffstat (limited to 'Working_Examples/83/CH9/EX9.2/example_9_2.sce')
-rwxr-xr-x | Working_Examples/83/CH9/EX9.2/example_9_2.sce | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/Working_Examples/83/CH9/EX9.2/example_9_2.sce b/Working_Examples/83/CH9/EX9.2/example_9_2.sce new file mode 100755 index 0000000..30758db --- /dev/null +++ b/Working_Examples/83/CH9/EX9.2/example_9_2.sce @@ -0,0 +1,48 @@ +//Chapter 9 +//Example 9.2 +//page 337 +//To calculate subtransient and momentary current +clear;clc; +mvab=25; +Gmva=25; +T1mva=25; T2mva=25; +Gkvb=11; //generator kV base +OHLkvb=66; //overhead line kV base +Mkvb=6.6; //motor kV base +Mmva=5; //motor mva + +XdG=%i*0.2; //Generator's subtransient reactance +XdM=%i*0.25; //Motor's subtransient reactance +XdM2=%i*0.3; //Motor's transient reactance +Xt1=%i*0.1; // step up transformer's reactance +Xt2=%i*0.1;//step down transformer's reactance +Xtl=%i*0.15 ;//trnasmission line's reactance + +//per unit calculation +XdM=(XdM*mvab)/Mmva ;//perunit impedance of each motor +printf('\nSubtransient reactance of each motor = j%0.2f pu\n',abs(XdM)); + +//(a)subtransient current in the fault +Isc=(3*(1/XdM))+(1/(XdG+Xt1+Xt2+Xtl)); +Ibase=(mvab*1000)/(sqrt(3)*Mkvb); +Isc=Isc*Ibase; +printf('\nSubtransient current in the fault =%0.1fA\n',abs(Isc)); + +//(b)subtransient current in the breaker B +IscB=(2*(1/XdM))+(1/(XdG+Xt1+Xt2+Xtl)); +IscB=IscB*Ibase; +printf('\nSubtransient current in breaker B=%0.1fA\n',abs(IscB)); + +//(c) to find the momentary current through breaker B +ImomB=1.6*IscB; +printf('\nMomentary current through the breaker B=%dA\n',abs(ImomB)); + +//(d) to compute current to be interrupted by breaker in 5 cycles +XdM2=(XdM2*mvab)/Mmva ;//perunit transient impedance of each motor +IscB=(2*(1/XdM2))+(1/(XdG+Xt1+Xt2+Xtl)); +IscB=IscB*Ibase; +ImomB=1.1*IscB; +printf('\nCurrent to be interrupted by breaker B in five cycles=%dA\n',abs(ImomB)); + + + |