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| author | priyanka | 2015-06-24 15:03:17 +0530 |
|---|---|---|
| committer | priyanka | 2015-06-24 15:03:17 +0530 |
| commit | b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b (patch) | |
| tree | ab291cffc65280e58ac82470ba63fbcca7805165 /503/CH3 | |
| download | Scilab-TBC-Uploads-b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b.tar.gz Scilab-TBC-Uploads-b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b.tar.bz2 Scilab-TBC-Uploads-b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b.zip | |
initial commit / add all books
Diffstat (limited to '503/CH3')
29 files changed, 782 insertions, 0 deletions
diff --git a/503/CH3/EX3.1/ch3_1.sci b/503/CH3/EX3.1/ch3_1.sci new file mode 100755 index 000000000..de947d3d0 --- /dev/null +++ b/503/CH3/EX3.1/ch3_1.sci @@ -0,0 +1,12 @@ +// To determine no load power factor,core loss current and magnetising current
+// and no load ckt parameters of transformer
+
+clc;
+Pi=50;
+V1=230;
+Io=2;
+pf=Pi/(V1*Io);disp(pf,'no load power factor');
+Im=Io*sind(acosd(pf));disp(Im,'magnetising current(A)');
+Ii=Io*pf;disp(Ii,'core loss current(A)');
+Gi=Pi/V1^2;disp(Gi,'Gi(mho)');
+Bm=Im/V1;disp(Bm,'Bm(mho)');
\ No newline at end of file diff --git a/503/CH3/EX3.10/ch3_10.sci b/503/CH3/EX3.10/ch3_10.sci new file mode 100755 index 000000000..e0680948d --- /dev/null +++ b/503/CH3/EX3.10/ch3_10.sci @@ -0,0 +1,22 @@ +//To find exciting current and expess impedence in pu in both HV and LV sides
+
+clc;
+
+V_BHV=2000;
+I_BHV=10;
+Z_BHV=V_BHV/I_BHV;
+
+V_BLV=200;
+I_BLV=100;
+Z_BLV=V_BLV/I_BLV;
+
+I_o=3;
+a=V_BHV/V_BLV;
+
+I_oLV=I_o/100; disp(I_oLV,'I_o(LV)pu=');
+I_oHV=I_o/(a*10); disp(I_oHV,'I_o(HV)pu=');
+
+Z=complex(8.2,10.2);
+ZHV=Z/Z_BHV; disp(ZHV,'Z(HV)pu=');
+z=Z/a^2;
+ZLV=z/Z_BLV; disp(ZLV,'Z(LV)pu=');
\ No newline at end of file diff --git a/503/CH3/EX3.11/ch3_11.sci b/503/CH3/EX3.11/ch3_11.sci new file mode 100755 index 000000000..4043674ef --- /dev/null +++ b/503/CH3/EX3.11/ch3_11.sci @@ -0,0 +1,20 @@ +// To calculate efficiency of transformer
+
+clc;
+
+V_2=200;
+I_2=100;
+pf=.8;
+P_o=V_2*I_2*pf; //power output
+
+P_i=120;
+P_c=300;
+k=1;
+P_L=P_i+k^2*P_c; //total losses
+
+n=1-(P_L/(P_o+P_L)); disp(n*100,'n(%)');
+
+K=sqrt(P_i/P_c); //max efficiency
+
+n_max=1-(2*P_i/(P_o*K+2*P_i)); //pf=.8
+disp(n_max*100,'n_max(%)');
\ No newline at end of file diff --git a/503/CH3/EX3.13/ch3_13.sci b/503/CH3/EX3.13/ch3_13.sci new file mode 100755 index 000000000..45d307cb6 --- /dev/null +++ b/503/CH3/EX3.13/ch3_13.sci @@ -0,0 +1,37 @@ +// Comparing all-day efficiencies for diff given load cycles
+
+clc;
+
+r=15; // kva rating
+n_max=.98;
+pf=1;
+P_o=20;
+P_i=r*(1-n_max)/2;
+k=r*pf/P_o;
+P_c=P_i/(k^2);
+function [W_o,W_in]=power(P_o,h)
+ k=P_o/20;
+ P_c=P_i*P_o/r;
+ W_o=P_o*h;
+ W_in=(P_o+P_i+(k^2)*P_c)*h;
+endfunction
+
+//(a)full load of 20kva 12hrs/day and no load rest of the day
+a=[20 12];
+[W_oa(1),W_ina(1)]=power(a(1),a(2));
+aa=[0 12];
+[W_oa(2),W_ina(2)]=power(aa(1),aa(2));
+disp(W_oa,'W_o(kWh) for a');
+disp(W_ina,'W_in(kWh) for a');
+n_ada=sum(W_oa)/sum(W_ina); disp(n_ada*100,'n_allday(a) in %age');
+
+//(b)full load of 20kva 4hrs/day and .4 of full load rest of the day
+b=[20 4];
+[W_ob(1),W_inb(1)]=power(b(1),b(2));
+bb=[8 20];
+[W_ob(2),W_inb(2)]=power(bb(1),bb(2));
+disp(W_ob,'W_o(kWh) for b');
+disp(W_inb,'W_in(kWh) for b');
+n_adb=sum(W_ob)/sum(W_inb); disp(n_adb*100,'n_allday(b) in %age');
+
+
diff --git a/503/CH3/EX3.14/ch3_14.sci b/503/CH3/EX3.14/ch3_14.sci new file mode 100755 index 000000000..2374e5020 --- /dev/null +++ b/503/CH3/EX3.14/ch3_14.sci @@ -0,0 +1,23 @@ +// To calculate volatage regulation, volatage at load terminals and operating efficiency
+
+clc;
+S=20*1000;
+V1=200;
+V2=2000;
+I1=S/V1;
+I2=S/V2;
+Rh=3;
+Xh=5.2;
+pf=0.8;
+phi=acosd(pf);
+Vha=V2+I2*(Rh*cosd(phi)+Xh*sind(phi)); //lagging
+Vrega=(Vha-V2)*100/V2; disp(Vrega,'vol-reg lagging(%)');
+Vhb=V2+I2*(Rh*cosd(phi)-Xh*sind(phi)); //leading
+Vregb=(Vhb-V2)*100/V2; disp(Vregb,'vol-reg leading(%)');
+
+V11=V2-I2*(Rh*cosd(phi)+Xh*sind(phi));
+v1=V11/I2; disp(v1,'V_L(V)');
+ploss=120+10*10*3;
+pop=v1*I1*cosd(phi);
+eff=(1-(ploss/(ploss+pop)))*100;
+disp(eff,'eff(%)');
\ No newline at end of file diff --git a/503/CH3/EX3.15/ch3_15.sci b/503/CH3/EX3.15/ch3_15.sci new file mode 100755 index 000000000..a141932ba --- /dev/null +++ b/503/CH3/EX3.15/ch3_15.sci @@ -0,0 +1,33 @@ +// To determine voltage regulation and efficiency
+
+clc;
+
+r=150*1000; //rating in va
+v1=2400;
+v2=240;
+a=v2/v1;
+R_hv=.2+.002/a^2;
+X_hv=.45+.0045/a^2;
+I_2fl=r/v2;
+pf=0.8 //lagging
+phi=acosd(pf);
+I_2=I_2fl*a;
+vd=I_2*(R_hv*cosd(phi)+X_hv*sind(phi));
+V2=v1;
+vr=(vd/V2)*100; disp(vr,'vol reg(%)');
+V1=v1+vd;
+P_out=r*pf;
+P_c=(I_2^2)*R_hv; //copper loss
+P_i=(V1^2)/10000;
+P_L=P_c+P_i;
+n=P_out/(P_out+P_L); disp(n*100,'eff(%)');
+
+I_o(1)=V1/(10*1000);
+I_o(2)=-V1/(1.6*1000); //inductive effect
+I2(1)=I_2*(cosd(phi));
+I2(2)=I_2*(-sind(phi));
+I_1=I_o+I2;
+b=sqrt(I_1(1)^2+I_1(2)^2);
+disp(b,'I_1(A)');
+pff=cosd(atand(I_1(2)/I_1(1)));
+disp(pff,'pf');
\ No newline at end of file diff --git a/503/CH3/EX3.16/ch3_16.sci b/503/CH3/EX3.16/ch3_16.sci new file mode 100755 index 000000000..0018d2072 --- /dev/null +++ b/503/CH3/EX3.16/ch3_16.sci @@ -0,0 +1,24 @@ +// to calculate voltage ratings,kva ratings and efficieny of autotransformer
+
+clc;
+
+AB=200;
+BC=2000;
+V_1=BC; disp(V_1,'V_1(V)');
+V_2=AB+BC; disp(V_2,'V_2(V)');
+r=20000; //rating of transformer
+I_2=r/AB;
+I_1=I_2+10;
+rr=V_2*I_2/1000; //kva rating of autotransformer
+disp(rr,'kva rating');
+ri=V_1*(I_1-I_2)/1000; //kva inductive
+rc=rr-ri;
+disp(ri,'kva transferred inductively');
+disp(rc,'kva transferred conductively');
+W_c=120; //core loss
+W_cu=300; //cu loss
+W_t=W_c+W_cu; //total loss
+pf=0.8;
+W=V_2*I_2*pf; //full load output
+n=1-(W_t/W);
+disp(n*100,'eff(%)');
\ No newline at end of file diff --git a/503/CH3/EX3.17/ch3_17.sci b/503/CH3/EX3.17/ch3_17.sci new file mode 100755 index 000000000..6c1ba9ef9 --- /dev/null +++ b/503/CH3/EX3.17/ch3_17.sci @@ -0,0 +1,23 @@ +// To determine the rating and full load efficiency of autotransformer
+
+clc;
+//when used as transformer
+v1=240;
+v2=120;
+r=12000;
+I1=r/v1;
+I2=r/v2;
+
+//when connected as autotransformer
+V1=240;
+V2=v1+v2;
+rr=I2*V2; disp(rr,'rating of autotransformer(va)');
+
+pf=1;
+P_o=r*pf; //output power
+n=.962 //efficiency at upf
+P_L=P_o*(1-n)/n;
+
+pff=.85 //if pf=.85
+Po=rr*pff;
+nn=1/(1+P_L/Po); disp(nn*100,'efficiency(%) at .85 pf is');
\ No newline at end of file diff --git a/503/CH3/EX3.18/ch3_18.sci b/503/CH3/EX3.18/ch3_18.sci new file mode 100755 index 000000000..7970ad308 --- /dev/null +++ b/503/CH3/EX3.18/ch3_18.sci @@ -0,0 +1,24 @@ +// To calculate sec. line voltage, line current and output va
+
+clc;
+
+disp('(a)Y/D conn');
+V_LY=6600;
+V_PY=V_LY/sqrt(3);
+a=12;
+V_PD=V_PY/a;
+V_LD=V_PD; disp(V_LD,'sec line voltage(V)');
+
+I_PY=10;
+I_PD=I_PY*a;
+I_LD=I_PD*sqrt(3); disp(I_LD,'sec. line current(A)');
+r=sqrt(3)*V_LD*I_LD; disp(r,'output rating(va)');
+
+disp('(b)D/Y conn');
+I_LD=10;
+I_PD=I_LD/sqrt(3);
+I_LY=I_PD*a; disp(I_LY,'sec. line current(A)');
+V_PD=6600;
+V_PY=V_PD/a;
+V_LY=V_PY*sqrt(3); disp(V_LY,'sec line voltage(V)');
+r=sqrt(3)*V_LY*I_LY; disp(r,'output rating(va)');
\ No newline at end of file diff --git a/503/CH3/EX3.19/ch3_19.sci b/503/CH3/EX3.19/ch3_19.sci new file mode 100755 index 000000000..0127b3b7e --- /dev/null +++ b/503/CH3/EX3.19/ch3_19.sci @@ -0,0 +1,34 @@ +// To compute all the currents and voltages in all windings of Y/D transformer
+
+clc;
+
+S=complex(500,100); //load is 500MW and 100MVar
+s=abs(S);
+r=s/3; //MVA rating of each single ph transformer
+
+V1=22; //D side
+V2=345; //Y side
+a=V2/(sqrt(3)*V1); //voltage rating of each single phase
+disp('Y side');
+V_A=(V2/sqrt(3))*complex(cosd(0),sind(0));
+V_B=(V2/sqrt(3))*complex(cosd(-120),sind(-120));
+V_C=(V2/sqrt(3))*complex(cosd(-240),sind(-240));
+
+V_AB=V_A-V_B; disp(V_AB,'V_AB(V)');
+V_BC=V_B-V_C; disp(V_BC,'V_BC(V)');
+V_CA=V_C-V_A; disp(V_CA,'V_CA(V)');
+
+IA=S/(3*V_A); disp(IA,'IA(A)');
+IB=S/(3*V_B); disp(IB,'IB(A)');
+IC=S/(3*V_C); disp(IC,'IC(A)');
+disp('D side');
+V_ab=V_A/a; disp(V_ab,'V_ab(V)');
+V_bc=V_B/a; disp(V_bc,'V_bc(V)');
+V_ca=V_C/a; disp(V_ca,'V_ca(V)');
+
+I_ab=a*IA;
+I_bc=a*IB;
+I_ca=a*IC;
+Ia=I_ab-I_bc; disp(Ia,'Ia(A)');
+Ib=I_bc-I_ca; disp(Ib,'Ib(A)');
+Ic=I_ca-I_ab; disp(Ic,'Ic(A)');
diff --git a/503/CH3/EX3.2/ch3_2.sci b/503/CH3/EX3.2/ch3_2.sci new file mode 100755 index 000000000..f413549b9 --- /dev/null +++ b/503/CH3/EX3.2/ch3_2.sci @@ -0,0 +1,39 @@ +// To calculate no load current and its pf and no load power drawn from mains
+
+clc;
+E=200;
+f=50;
+N1=150; // no of turns
+b1=.1;
+b2=.05;
+phi_max=E/(4.44*f*N1);
+disp(phi_max,'flux(Wb)');
+B_max=phi_max/(b1*b2);
+disp(B_max,'B_max(T)');
+
+H_max=250; //According to B_max, H_max is 250AT/m
+l_c=.2*(3.0+3.5); //length of core
+AT_max=H_max*l_c;
+disp(AT_max,'AT_max');
+T_max=N1;
+I_mmax=AT_max/T_max;
+I_mrms=I_mmax/2^.5;
+disp(I_mrms,'I_mrms(A)');
+
+v=2*(20*10*5)+2*(45*10*5);
+
+d=.0079; //density of core material
+w=v*d;
+
+cl=3; //core loss/kg
+closs=w*cl;
+disp(closs,'core loss(W)');
+I_i=closs/E;
+disp(I_i,'I_i(A)');
+function [r,pff]=rect2polar(x,y)
+ r=sqrt(x^2+y^2);
+ pff=cosd(atand(y/x));
+endfunction
+[I_o,pf]=rect2polar(I_i,-I_mmax);
+disp(I_o,'no load current(A)');
+disp(pf,'no load power factor');
\ No newline at end of file diff --git a/503/CH3/EX3.20/ch3_20.sci b/503/CH3/EX3.20/ch3_20.sci new file mode 100755 index 000000000..021a4da78 --- /dev/null +++ b/503/CH3/EX3.20/ch3_20.sci @@ -0,0 +1,23 @@ +// to find the load voltage when it draws rated current from transformer
+
+clc;
+// here pu method is used
+r=20; //kva rating of three 1-ph transformer
+MVA_B=r*3/1000;
+v2=2*sqrt(3); //in kv voltage base on hv side
+v1=.2; //in kv voltage base on lv side
+
+z1=complex(.0004,.0015); //feeder impedence
+Z1=z1*MVA_B/v1^2; // lv line(pu)
+z2=complex(.13,.95); //load impedence
+Z2=z2*MVA_B/v2^2; // hv line(pu)
+z_T=complex(.82,1.02);
+ZTY=z_T*MVA_B/v2^2; // star side(pu)
+
+Ztot=Z1+Z2+ZTY;
+V1=1; //sending end voltage [pu]
+I1=1; //rated current(pu)
+pf=.8;
+V2=V1-I1*(real(Ztot)*pf+imag(Ztot)*.6); //load voltage(pu)
+V2v=V2*v1;
+disp(V2v,'load voltage(kv)');
\ No newline at end of file diff --git a/503/CH3/EX3.21/ch3_21.sci b/503/CH3/EX3.21/ch3_21.sci new file mode 100755 index 000000000..252172e75 --- /dev/null +++ b/503/CH3/EX3.21/ch3_21.sci @@ -0,0 +1,23 @@ +// to calculate fault currentin feeder lines,primary and secondary lines of receiving end transformers
+
+clc;
+
+r=60; //kva rating of 3-ph common base
+s=200; //kva rating of 3ph transformer
+//sending end
+X_Tse=.06*r/s; //.06= reactance of transformer based on its own rating
+//in 2 kv feeder
+V_B=2000/sqrt(3); //line to neutral
+I_B=r*1000/(sqrt(3)*2000);
+Z_B=V_B/I_B;
+X_feeder=0.7/Z_B; //feeder reactance=0.7
+//receiving end
+X_Tre=0.0051;
+X_tot=X_Tse+X_feeder+X_Tre;
+V_se=20/20;
+I_fc=V_se/X_tot; //feeder current
+
+I_f=I_fc*I_B; disp(I_f,'current in 2kv feeder(A)');
+I_t1=I_f/sqrt(3); disp(I_t1,'current in 2kv winding of transformer(A)');
+I_t2=I_t1*10; disp(I_t2,'current in 200kv winding of transformer(A)');
+I_l=I_t2*sqrt(3); disp(I_l,'current at load terminals(A)');
\ No newline at end of file diff --git a/503/CH3/EX3.22/ch3_22.sci b/503/CH3/EX3.22/ch3_22.sci new file mode 100755 index 000000000..d68092b8d --- /dev/null +++ b/503/CH3/EX3.22/ch3_22.sci @@ -0,0 +1,30 @@ +// To calculate voltage and kva rating of 1-ph transformer
+
+clc;
+
+V_p=33; //primary side voltage(V)
+V_s=11; //secondary side voltage(V)
+V_p1=V_p/sqrt(3); //per ph primary side voltage(V)
+V_p2=V_s/sqrt(3); //per ph secondary side voltage(V)
+
+r=6000; //kva rating 3-ph
+s=r/3; //per phase
+disp('Y/Y conn');
+disp(V_p1,'primary side ph voltage(V)');
+disp(V_p2,'secondary side ph voltage(V)');
+disp(s,'kva rating of transformer');
+
+disp('Y/D conn');
+disp(V_p1,'primary side ph voltage(V)');
+disp(V_s,'secondary side ph voltage(V)');
+disp(s,'kva rating of transformer');
+
+disp('D/Y conn');
+disp(V_p,'primary side ph voltage(V)');
+disp(V_p2,'secondary side ph voltage(V)');
+disp(s,'kva rating of transformer');
+
+disp('D/D conn');
+disp(V_p,'primary side ph voltage(V)');
+disp(V_s,'secondary side ph voltage(V)');
+disp(s,'kva rating of transformer');
diff --git a/503/CH3/EX3.23/ch3_23.sci b/503/CH3/EX3.23/ch3_23.sci new file mode 100755 index 000000000..8994386dc --- /dev/null +++ b/503/CH3/EX3.23/ch3_23.sci @@ -0,0 +1,30 @@ +// to calculate (a)reactance in ohms(b)line voltage,kva rating,series reactance for Y/Y and Y/D conn
+
+clc;
+Xpu=0.12; // of 1-ph transformer
+
+function [X]=Xohm(kv,MVA)
+ X=(Xpu*kv^2)/MVA;
+endfunction
+
+disp('(a)');
+MVAa=75*10^-3;
+Vhv=6.6;
+Vlv=.4;
+Xhv=Xohm(Vhv,MVAa); disp(Xhv,'X(ohm)of hv side');
+Xlv=Xohm(Vlv,MVAa); disp(Xlv,'X(ohm)of lv side');
+
+disp('(b)');
+disp('Y/Y');
+MVAb=MVAa*3;
+Vhv=6.6*sqrt(3); disp(Vhv,'V_hv(kV)');
+Vlv=.4*sqrt(3); disp(Vlv,'V_lv(kV)');
+Xhv=Xohm(Vhv,MVAb); disp(Xhv,'X(ohm)of hv side');
+Xlv=Xohm(Vlv,MVAb); disp(Xlv,'X(ohm)of lv side');
+
+disp('Y/D');
+MVAb=MVAa*3;
+Vhv=6.6*sqrt(3); disp(Vhv,'V_hv(kV)');
+Vlv=.4; disp(Vlv,'V_lv(kV)');
+Xhv=Xohm(Vhv,MVAb); disp(Xhv,'X(ohm)of hv side');
+Xlv=Xohm(Vlv,MVAb); disp(Xlv,'X(ohm)of lv side');
diff --git a/503/CH3/EX3.24/ch3_24.sci b/503/CH3/EX3.24/ch3_24.sci new file mode 100755 index 000000000..efdc473c2 --- /dev/null +++ b/503/CH3/EX3.24/ch3_24.sci @@ -0,0 +1,30 @@ +//find how 2 transformers connected in parallel share the load
+
+clc;
+Z1=complex(.012,.06);
+Z2=2*complex(.014,.045);
+Z=Z1+Z2;
+r=800; //kva rating
+pf=.8;
+S_L=r*(complex(pf,-1*sind(acosd(pf))));
+S_1=S_L*Z2/Z;disp(S_1,'load by first transformer(kVA)');
+S_2=S_L*Z1/Z;disp(S_2,'load by second transformer(kVA)');
+
+S_2rated=300;
+S_Lmax=S_2rated*abs(Z)/abs(Z1);
+disp(S_Lmax,'max load by both transformer(kVA)');
+
+r1=600; //kva
+V=440;
+Z1actual=Z1*V/(r1*1000/V);
+Z2actual=Z2*V/(r1*1000/V);
+Zactual=Z1actual+Z2actual;
+Z_Lact=V^2/(S_L*1000);
+
+V1=445;
+I1=(V1*Z2actual-10*Z_Lact)/(Z1actual*Z2actual+Z_Lact*Zactual);
+I2=(V1*-1*Z1actual-10*Z_Lact)/(Z1actual*Z2actual+Z_Lact*Zactual);
+S1=V*I1/1000; disp(S1,'kVA of first transformer');
+S2=V*I2/1000; disp(S2,'kVA of second transformer');
+Pout=abs(S1)*cosd(atand(imag(S1)/real(S1)))+abs(S2)*cosd(atand(imag(S2)/real(S2)));
+disp(Pout,'total output power(kW)');
\ No newline at end of file diff --git a/503/CH3/EX3.25/ch3_25.sci b/503/CH3/EX3.25/ch3_25.sci new file mode 100755 index 000000000..1531c53ed --- /dev/null +++ b/503/CH3/EX3.25/ch3_25.sci @@ -0,0 +1,32 @@ +//find pu value of the equivalent ckt,steady state short ckt current and voltages
+
+clc;
+r=5; //MVA rating
+V_Bp=6.35; //for primary
+I_Bp=r*1000/V_Bp;
+V_Bs=1.91; //for secondary
+I_Bs=r*1000/V_Bs;
+//from resp tests
+V1=.0787;
+I1=.5;
+V2=.1417;
+I2=.5;
+V3=.1212;
+I3=.5;
+X12=V1/I1;
+X13=V2/I2;
+X23=V3/I3;
+X1=I1*(X12+X13-X23);
+X2=I2*(X23+X12-X13);
+X3=I3*(X13+X23-X12);
+disp(X1,'X1(pu)');
+disp(X2,'X2(pu)');
+disp(X3,'X3(pu)');
+
+V1=1;
+I_sc=V1/X13;
+I_scp=I_sc*I_Bp; disp(I_scp,'sc current primary side(A)');
+I_sct=I_sc*r*1000*1000/(400/sqrt(3)); disp(I_sct,'sc current tertiary side(A)');
+V_A=I_sc*X3;
+V_Aact=V_A*1.91*sqrt(3);
+disp(V_Aact,'V_A(actual) line to line(kV)');
\ No newline at end of file diff --git a/503/CH3/EX3.26/ch3_26.sci b/503/CH3/EX3.26/ch3_26.sci new file mode 100755 index 000000000..f886e4f7d --- /dev/null +++ b/503/CH3/EX3.26/ch3_26.sci @@ -0,0 +1,18 @@ +// to calculate line currents of 3 ph side
+
+clc;
+N1=6600;
+N2=100;
+a=N1/N2;
+b=(sqrt(3)/2)*a;
+P=400; //kW
+pfa=.707;
+pfb=1;
+V=100;
+Ia=P*1000/(V*pfa);
+Ib=P*2*1000/(V*pfb);
+I_A=Ia/b;disp(I_A,'I_A(A)');
+I_BC=Ib/a;
+I_B=I_BC-49.5*complex(pfa,pfa); disp(abs(I_B),'I_B(A)');
+I_C=I_BC+49.5*complex(pfa,-1*pfa);disp(abs(I_C),'I_C(A)');
+
diff --git a/503/CH3/EX3.27/ch3_27.sci b/503/CH3/EX3.27/ch3_27.sci new file mode 100755 index 000000000..e4a3afec3 --- /dev/null +++ b/503/CH3/EX3.27/ch3_27.sci @@ -0,0 +1,23 @@ +//to calculate magnitude and phase of secondary current
+
+clc;
+X1=505; //uohm
+X2=551; //uohm
+R1=109; //uohm
+R2=102; //uohm
+Xm=256; //mohm
+I1=250; //A
+I22=complex(0,Xm*1000)*I1/(complex(R1,X2+Xm*1000));
+N1=250;
+N2=5;
+I2=I22*(N2/N1);
+disp(abs(I2),'current magnitude(A)');
+disp(atand(imag(I2)/real(I2)),'phase(degree)');
+disp('now Rb is introduced in series');
+Rbb=200; //uohm
+Rb=(N2/N1)^2*Rbb;
+I22=complex(0,Xm*1000)*I1/(complex((R1+Rb),X2+Xm*1000));
+I2=I22*(N2/N1);
+disp(abs(I2),'current magnitude(A)');
+disp(atand(imag(I2)/real(I2)),'phase(degree)');
+disp('no chnage as Rb is negligible');
\ No newline at end of file diff --git a/503/CH3/EX3.28/ch3_28.sci b/503/CH3/EX3.28/ch3_28.sci new file mode 100755 index 000000000..13495c066 --- /dev/null +++ b/503/CH3/EX3.28/ch3_28.sci @@ -0,0 +1,36 @@ +//to calculate sec voltage magnitude and ph
+
+clc;
+a=6000/100; //turn ratio
+R1=780;
+R2=907;
+X1=975;
+X2=1075;
+Xm=443*1000;
+disp('sec open');
+//Zb=inf;
+V1=6500;
+V22=complex(0,Xm)*V1/complex(R1,Xm);
+V2=V22/a;
+disp(abs(V2),'voltage magnitude(V)');
+disp(atand(imag(V2)/real(V2)),'phase(deg)');
+
+disp('when Zb=Rb');
+Rb=1;
+Rbb=Rb*a^2;
+Zm=complex(0,Xm/1000)*Rbb/complex(0,Xm/1000)+Rbb;
+R=complex(R1/1000,X1/1000)+Zm;
+Vm=Zm*V1/R;
+V2=Vm/a;
+disp(abs(V2),'voltage magnitude(V)');
+disp(atand(imag(V2)/real(V2)),'phase(deg)');
+
+disp('when Zb=jXb');
+Rb=complex(0,1);
+Rbb=Rb*a^2;
+Zm=complex(0,Xm/1000)*Rbb/complex(0,Xm/1000)+Rbb;
+R=complex(R1/1000,X1/1000)+Zm;
+Vm=Zm*V1/R;
+V2=Vm/a;
+disp(abs(V2),'voltage magnitude(V)');
+disp(atand(imag(V2)/real(V2)),'phase(deg)');
diff --git a/503/CH3/EX3.29/ch3_29.sci b/503/CH3/EX3.29/ch3_29.sci new file mode 100755 index 000000000..cb70ee564 --- /dev/null +++ b/503/CH3/EX3.29/ch3_29.sci @@ -0,0 +1,19 @@ +//to calculate L1 and L2 and coupling cofficient
+
+clc;
+a=10;
+V_p=200;
+I_p=4;
+Xm=V_p/I_p;
+f=50;
+L1=Xm/(2*%pi*f);disp(L1,'L1(H)');
+V_s=1950;
+w_max=V_s/(sqrt(2)*%pi*f);
+M=w_max/(sqrt(2)*I_p);
+
+v_s=2000;
+i_s=.41;
+w_max=sqrt(2)*i_s*M;
+E1=sqrt(2)*%pi*f*w_max;
+L2=v_s/(sqrt(2)*%pi*f*sqrt(2)*i_s);disp(L2,'L2(H)');
+k=M/(sqrt(L1)*sqrt(L2));disp(k,'coupling coeff');
\ No newline at end of file diff --git a/503/CH3/EX3.3/ch3_3.sci b/503/CH3/EX3.3/ch3_3.sci new file mode 100755 index 000000000..1c9c2fc6a --- /dev/null +++ b/503/CH3/EX3.3/ch3_3.sci @@ -0,0 +1,35 @@ +// To calculate primary and scondary side impedences,current and their pf and real power
+// and calculate terminal voltage
+
+clc;
+N_1=150;
+N_2=75;
+
+a=N_1/N_2;
+
+Z_2=[5,30]; //polar(magnitude,phase diff)
+disp(Z_2,'secondary impedence(ohm)');
+Z_1=[a^2*Z_2(1),Z_2(2)];
+disp(Z_1,'primary impedence(ohm)');
+
+V_1=[200,0]; //polar(magnitde,phase diff)
+V_2=[V_1(1)/a,V_1(2)];
+disp(V_2,'secondary terminal voltage(V)');
+
+I_2(1)=V_2(1)/Z_2(1);
+I_2(2)=V_2(2)-Z_2(2);
+disp(I_2,'I_2=');
+pf=cosd(I_2(2));
+disp(pf,'pf lagging=');
+
+I_1(1)=I_2(1)/a;
+I_1(2)=I_2(2);
+disp(I_1,'I_1(A)');
+pf=cosd(I_1(2));
+disp(pf,'pf lagging=');
+
+P_2=V_2(1)*I_2(1)*cosd(I_2(2));
+disp(P_2,'secondary power output(W)=');
+//P_1=primary power output
+P_1=P_2 //as the transormer is lossless
+disp(P_1,'primary power output(W)=');
diff --git a/503/CH3/EX3.30/ch3_30.sci b/503/CH3/EX3.30/ch3_30.sci new file mode 100755 index 000000000..1c95e58c3 --- /dev/null +++ b/503/CH3/EX3.30/ch3_30.sci @@ -0,0 +1,20 @@ +// to calculate leakage inductance, magnetisisng inductance,mutual inductance and self-inductance
+
+clc;
+V1=2400;
+V2=240;
+a=V1/V2;
+R1=.2;
+X1=.45;
+Rl=10000;
+R2=2*10^-3;
+X2=4.5*10^-3;
+Xm=1600;
+f=50;
+l1=X1/(2*%pi*f);disp(l1,'leakage inductance ie l1(H)');
+l2=X2/(2*%pi*f);disp(l2,'l2(H)');
+Lm1=Xm/(2*%pi*f);disp(Lm1,'magnetising inductance(H)');
+L1=Lm1+l1;disp(L1,'self-inductance ie L1(H)');
+M=Lm1/a;
+L2=l2+M/a;disp(L2,'L2(H)');
+k=M/sqrt(L1*L2);disp(k,'coupling factor');
\ No newline at end of file diff --git a/503/CH3/EX3.31/ch3_31.sci b/503/CH3/EX3.31/ch3_31.sci new file mode 100755 index 000000000..1f636ec28 --- /dev/null +++ b/503/CH3/EX3.31/ch3_31.sci @@ -0,0 +1,31 @@ +//to calculate %voltage reg and efficiency
+
+clc;
+P=500000;
+V1=2200;
+V2=1100;
+V0=110;
+I0=10;
+P0=400;
+Y0=I0/V0;
+Gi=P0/(V0^2);
+Bm=sqrt(Y0^2-Gi^2);
+Vsc=90;
+Isc=20.5;
+Psc=808;
+Z=Vsc/Isc;
+R=Psc/Isc^2;
+X=sqrt(Z^2-R^2);
+TR=V1/V2;
+Gi_HV=Gi/TR^2;
+Bm_HV=Bm/TR^2;
+R_LV=R/TR^2;
+X_LV=X/TR^2;
+I2=P/V2;
+pf=.8;
+Th=acos(pf);
+dV=I2*(R_LV*cos(Th)+X_LV*sin(Th));
+VR=(dV/V2)*100; disp(VR,'voltage regulation(%)');
+Pi=P0;
+Pc=Psc;
+n=P*100/(P+Pi+Pc);disp(n,'eff(%)');
\ No newline at end of file diff --git a/503/CH3/EX3.4/ch3_4.sci b/503/CH3/EX3.4/ch3_4.sci new file mode 100755 index 000000000..4df207dbb --- /dev/null +++ b/503/CH3/EX3.4/ch3_4.sci @@ -0,0 +1,27 @@ +// To calculate primary current and its pf
+
+clc;
+
+function [x,y]=polar2rect(r,theta)
+ x=r*cosd(theta);
+ y=r*sind(theta);
+endfunction
+
+function [r,theta]=rect2polar(x,y)
+ r=sqrt(x^2+y^2);
+ theta=atand(y/x);
+endfunction
+
+I_2=[10 -30];
+[I_2r(1),I_2r(2)]=polar2rect(I_2(1),I_2(2));
+
+I_0=[1.62 -71.5];
+[I_0r(1),I_0r(2)]=polar2rect(I_0(1),I_0(2));
+
+I_1r=I_0r+I_2r;
+
+[I_1(1),I_1(2)]=rect2polar(I_1r(1),I_1r(2));
+disp(I_1(1),'primary current(A)=');
+pf=cosd(I_1(2));
+disp(pf,'power factor=');
+
diff --git a/503/CH3/EX3.5/ch3_5.sci b/503/CH3/EX3.5/ch3_5.sci new file mode 100755 index 000000000..974f08dff --- /dev/null +++ b/503/CH3/EX3.5/ch3_5.sci @@ -0,0 +1,20 @@ +// Equivalent circuit referred to(i)HV side (ii)LV side
+
+clc;
+
+N_1=2000;
+N_2=200;
+
+a=N_1/N_2;
+
+Z_2=complex(.004,.005); //low voltage impedence
+Z_2hv=a^2*Z_2;
+disp(Z_2hv,'Z_2 referred to hv side(ohm)'); //when referred to hv side
+
+Y_0=complex(.002,-.015); //shunt branch admittance
+Y_0hv=Y_0/a^2;
+disp(Y_0hv,'Y_0 referred to hv side(mho)');
+
+Z_1=complex(.42,.52); //low voltage impedence
+Z_1lv=Z_1/a^2;
+disp(Z_1lv,'Z_1 referred to lv side(ohm)');
\ No newline at end of file diff --git a/503/CH3/EX3.6/ch3_6.sci b/503/CH3/EX3.6/ch3_6.sci new file mode 100755 index 000000000..9523688a2 --- /dev/null +++ b/503/CH3/EX3.6/ch3_6.sci @@ -0,0 +1,33 @@ +// To find the voltage at the load end of the transformer when load is drawing transformer current
+
+clc;
+
+I=20/2; //rated load current(hv side)
+
+Z1=[.25,1.4]; //impedence of feeder (REAL,IMAGINERY)
+Z2=[.82,1.02]; //impedence of transformer (REAL,IMAGINERY)
+
+Z=Z1+Z2;
+disp(Z,'Z(ohm)');
+
+pf=.8;
+phi=acosd(pf);
+
+//from phasor diagram
+
+R=Z(1);
+X=Z(2);
+AF=I*X*cosd(phi);
+FE=I*R*sind(phi);
+AE=AF-FE;
+OA=2000;
+OE=sqrt(OA^2-AE^2);
+
+BD=I*R*cosd(phi);
+DE=I*X*sind(phi);
+BE=BD+DE;
+V1=OE; disp(V1,'V1(V)');
+V2=V1-BE; disp(V2,'V2(V)');
+
+loadvol=V2/10; //referred to LV side
+disp(loadvol,'load voltage(V)');
diff --git a/503/CH3/EX3.7/ch3_7.sci b/503/CH3/EX3.7/ch3_7.sci new file mode 100755 index 000000000..6c064e419 --- /dev/null +++ b/503/CH3/EX3.7/ch3_7.sci @@ -0,0 +1,31 @@ +// Approx equivalent ckt referred to hv and lv sides resp,
+
+clc;
+//open ckt test data with HV side open
+ocv=200;
+oci=4;
+ocp=120;
+//short ckt test data with LV side open
+scv=60;
+sci=10;
+scp=300;
+//OC test(LV side)
+Y_o=oci/ocv; disp(Y_o,'Y_o(mho)');
+G_i=ocp/ocv^2; disp(G_i,'G_i(mho)');
+B_m=sqrt(Y_o^2-G_i^2); disp(B_m,'B_m(mho)');
+//SC test(HV side)
+Z=scv/sci; disp(Z,'Z(ohm)');
+R=scp/sci^2; disp(R,'R(ohm)');
+X=sqrt(Z^2-R^2); disp(X,'X(ohm)');
+
+N_H=2000;
+N_L=200;
+a=N_H/N_L; //transformation ratio
+
+//Equivalent ckt referred to HV side
+G_iHV=G_i/a^2; disp(G_iHV,'G_i(HV)mho');
+B_mHV=B_m/a^2; disp(B_mHV,'B_m(HV)mho');
+
+//Equivalent ckt referred to LV side
+RLV=R/a^2; disp(RLV,'R(LV)ohm');
+XLV=X/a^2; disp(XLV,'X(LV)ohm');
\ No newline at end of file diff --git a/503/CH3/EX3.8/ch3_8.sci b/503/CH3/EX3.8/ch3_8.sci new file mode 100755 index 000000000..c5748c608 --- /dev/null +++ b/503/CH3/EX3.8/ch3_8.sci @@ -0,0 +1,30 @@ +// to calculate (a)open ckt current,power and pf when LV excited at rated voltage
+// (b) voltage at which HV side is excited, ip power and its pf
+
+clc;
+r=150000; //rating(VA)
+V1=2400;
+V2=240;
+a=V1/V2;
+
+R_1=.2;
+X_1=.45;
+R_i=10000;
+R_2=2*10^-3;
+X_2=4.5*10^-3;
+X_m=1600;
+//Referring the shunt parameters to LV side
+R_iLV=R_i/a^2;
+X_mLV=X_m/a^2;
+I_oLV=[V2/100 V2/16];
+I_o=sqrt(I_oLV(1)^2+I_oLV(2)^2); disp(I_o,'I_o(A)');
+pf=cosd(atand(I_oLV(2)/I_oLV(1))); disp(pf,'pf');
+//equivalent series parameters referred to HVside
+R=R_1+R_2*a^2;
+X=X_1+X_2*a^2;
+Z=complex(R,X); disp(Z,'Z(ohm)');
+z=[R X];
+I_flHV=r/V1;
+V_scHV=I_flHV*sqrt(R^2+X^2);
+P_sc=I_flHV^2*R; disp(P_sc,'P_sc(W)');
+pf_sc=cosd(atand(X/R)); disp(pf_sc,'pf_sc');
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