clc clear disp('example 13.3') pa1=20000 ;pa2=30000 //kva in in 3 ph power va1=11 ;va2=11 //voltage in kilo volts pt1=20000 ;pt2=30000//kva of 3 ph transformer vpt1=11 ;vpt2=11//voltage of primery of transformer vst1=132 ;vst2=132//voltage of secondary of transformer xg1=0.5 ;xg2=0.65 //reactance of generator xt1=0.05 ;xt2=0.05 //reactance of transformer with their own kva pb=pa2;vbg=va2;vbt=vpt2;//assumeing base quantoties xtn1=xt1*pb/pa1 ;xtn2=xt2*pb/pa2 //transformer reactance with new base xgn1=xg1*pb/pa1;xgn2=xg2*pb/pa2 xn1=xtn1+xgn1;xn2=xtn2+xgn2 //reactancee up to fault from each generator xn=(xn1*xn2)/(xn1+xn2) //equalent reactance between generator and fault sckva=pb/xn ; //short circuit KVA pf=50000 //fault kva rating xf=pb/pf //reactance from fault xx=xf*xn1/(xn1-xf) x=xx-xn2 //reactance to be added bi=(vst1^2)*1000/(pb) xo=x*bi printf(" reactance to be added in circuit of generator 2 have %.1f p.u. \n reactance in ohms %.1f",x,xo)