10 files changed, 378 insertions, 0 deletions
diff --git a/1319/CH3/EX3.1/3_1.sce b/1319/CH3/EX3.1/3_1.sce
new file mode 100644
index 000000000..4fbd5abc2
--- /dev/null
+++ b/1319/CH3/EX3.1/3_1.sce
@@ -0,0 +1,26 @@
+// To determine the parameters of a balanced 3 phase star connected to a resistive load
+
+clc;
+clear;
+
+V=208;
+Vph=V/sqrt(3);
+R=35;
+
+// Star Conncected load has its line current = phase current
+
+Ia=Vph/R;
+Ib=Ia*(expm(%i*(-2*%pi/3)));
+Ic=Ia*(expm(%i*(2*%pi/3)));
+
+Pperphase= (abs(Ia)^2)*R;
+
+Pt=3*Pperphase;
+
+// Resistive Load, p.f is unity
+
+pf=1;
+
+printf('The power factor is %g \n',pf)
+printf('The total power dissipated = %g W \n',Pt)
+printf('The currents of the system are\n Ia = %g /_0 A \n Ib = %g /_-120 A \n Ic = %g /_120 A \n',abs(Ia),abs(Ib),abs(Ic)) 
diff --git a/1319/CH3/EX3.10/3_10.sce b/1319/CH3/EX3.10/3_10.sce
new file mode 100644
index 000000000..c5e3f0cde
--- /dev/null
+++ b/1319/CH3/EX3.10/3_10.sce
@@ -0,0 +1,57 @@
+// Two wattmeter power dertermination for a delta system
+
+clc;
+clear;
+
+V=250; // Phase Voltage
+
+// Phase Voltage in RYB sequnce
+Vry=V*(expm(%i*0));
+Vyb=V*(expm(%i*-2*%pi/3));
+Vbr=V*(expm(%i*2*%pi/3));
+
+// Resitances of the RYB limbs
+Rry=10+%i*10;
+Ryb=20-%i*15;
+Rbr=10+%i*20;
+
+// Phase Currents in RYB
+
+Iry= Vry/Rry;
+Iyb= Vyb/Ryb;
+Ibr= Vbr/Rbr;
+
+// Phase Current Angles wrt to Vr
+
+ary=atand(imag(Iry)/real(Iry));
+ayb=atand(imag(Iyb)/real(Iyb));
+abr=atand(imag(Ibr)/real(Ibr));
+
+// Line Currents in RYB 
+Ir=Iry-Ibr;
+Iy=Iyb-Iry;
+Ib=Ibr-Iyb;
+
+W1=real(-Vbr*conj(Ir));
+W2=real(Vyb*conj(Iy));
+
+Wt= W1+W2; // Total Power
+
+printf('i)\n')
+printf(' The Currents in each branch are : \n')
+printf(' Branch RY = %g/_%g A \n',abs(Iry),ary)
+printf(' Branch YB = %g/_%g A \n',abs(Iyb),ayb)
+printf(' Branch BR = %g/_%g A \n',abs(Ibr),abr)
+
+printf('ii) \n')
+printf('The line currents in RYB sequence are : \n')
+disp(Ir,' R line :')
+printf(' Magnitude = %g A \n',abs(Ir))
+disp(Iy,' Y line :')
+printf(' Magnitude = %g A\n',abs(Iy))
+disp(Ib,' B line :')
+printf(' Magnitude = %g A\n \n',abs(Ib))
+
+// Precision is more, The Text book includes round off error
+printf(' W1 = %g W\n',W1)
+printf(' W2 = %g W\n',W2)
diff --git a/1319/CH3/EX3.2/3_2.sce b/1319/CH3/EX3.2/3_2.sce
new file mode 100644
index 000000000..062bcb53f
--- /dev/null
+++ b/1319/CH3/EX3.2/3_2.sce
@@ -0,0 +1,31 @@
+// To determine the parameters of a balanced 3 phase star connected to an impedance
+
+clc;
+clear;
+
+V=208;
+Vph=V/sqrt(3);
+Z=15+(%i*20);
+
+// Star Conncected load has its line current = phase current
+
+Ia=Vph/Z;
+Ib=Ia*(expm(%i*(-2*%pi/3)));
+Ic=Ia*(expm(%i*(2*%pi/3)));
+
+Pperphase= (abs(Ia)^2)*real(Z);
+
+Pt=3*Pperphase;
+
+Atheta=atand(imag(Ia)/real(Ia));
+Btheta=atand(imag(Ib)/real(Ib));
+Ctheta=atand(imag(Ic)/real(Ic));
+
+pf=cosd(Atheta);
+
+printf('The power factor is %g lagging \n',pf)
+printf('The total power dissipated = %g W \n',Pt)
+printf('The currents of the system are \n')
+printf('Ia= %g /_%g A \n',abs(Ia),Atheta)
+printf('Ib= %g /_%g A \n',abs(Ib),Btheta-180)
+printf('Ic= %g /_%g A \n',abs(Ic),Ctheta) 
diff --git a/1319/CH3/EX3.3/3_3.sce b/1319/CH3/EX3.3/3_3.sce
new file mode 100644
index 000000000..7ca2e1e9d
--- /dev/null
+++ b/1319/CH3/EX3.3/3_3.sce
@@ -0,0 +1,37 @@
+//To determine the potential of the star point and line currents
+
+clc;
+clear;
+
+Zr=10*(expm(%i*%pi/6));
+Zy=12*(expm(%i*%pi/4));
+Zb=15*(expm(%i*2*%pi/9));
+
+V=440;
+Vph=V/(sqrt(3));
+
+//Phase Voltages
+Vr=Vph*(expm(%i*0));
+Vy=Vph*(expm(%i*-2*%pi/3));
+Vb=Vph*(expm(%i*2*%pi/3));
+
+Vs=((Vr/Zr)+(Vy/Zy)+(Vb/Zb))/((1/Zr)+(1/Zy)+(1/Zb));
+
+tvs=atand(imag(Vs)/real(Vs)); // Phase Angle of the star point voltage
+
+Ia=(Vr-Vs)/Zr;
+iat=atand(imag(Ia)/real(Ia)); // Angle of current in phase R
+Ib=(Vy-Vs)/Zy;
+ibt=atand(imag(Ib)/real(Ib)); // Angle of current in phase Y
+Ic=(Vb-Vs)/Zb;
+ict=atand(imag(Ic)/real(Ic)); // Angle of current in phase B
+
+I=Ia+Ib+Ic;
+I=ceil(real(I)*1000)+%i*(ceil(imag(I)*1000));
+
+printf('The potential of the star point = %g /_%g V \n',abs(Vs),tvs)
+printf('The line currents are : \n')
+printf('R phase current = %g /_%g A \n',abs(Ia),iat)
+printf('Y phase current = %g /_%g A \n',abs(Ib),ibt-180)
+printf('B phase current = %g /_%g A \n',abs(Ic),ict)
+
diff --git a/1319/CH3/EX3.4/3_4.sce b/1319/CH3/EX3.4/3_4.sce
new file mode 100644
index 000000000..de3c5306c
--- /dev/null
+++ b/1319/CH3/EX3.4/3_4.sce
@@ -0,0 +1,33 @@
+//To determine the line currents if one inductor is short circuited
+
+clc;
+clear;
+
+V=460; // Line to Line voltage
+pf=0.8; // Power Factor
+P=8*(10^3); // Power Consumed by the network
+
+Vph=V/sqrt(3);
+
+Iph=P/(sqrt(3)*V*pf);
+
+theta=acos(pf);// Power factor angle
+Z=(Vph/Iph)*(expm(%i*theta));
+
+Va=V*expm(%i*0); // Voltage of Phase A
+Vc=V*expm(%i*-2*%pi/3); // Voltage of Phase C
+
+Ia=Va/Z; // Current in phase A
+Ic=Vc/Z;// Current in phase C
+
+iat=atand(imag(Ia)/real(Ia)); // Phase angle of Ia
+ict=atand(imag(Ic)/real(Ic));// Phase angle of Ic
+
+tac=iat-ict; // Angle between current Ia and Ic
+
+Ib=sqrt((abs(Ia)^2)+(abs(Ic)^2)+(2*abs(Ia)*abs(Ic)*cosd(tac)));
+
+printf('The line currents are : \n')
+printf('Phase a = %g/_%g A \n',abs(Ia),iat)
+printf('Phase b = %g A \n',abs(Ib))
+printf('Phase c = %g/_%g A \n',abs(Ic),ict)
diff --git a/1319/CH3/EX3.5/3_5.sce b/1319/CH3/EX3.5/3_5.sce
new file mode 100644
index 000000000..2d0859943
--- /dev/null
+++ b/1319/CH3/EX3.5/3_5.sce
@@ -0,0 +1,23 @@
+//To find line current and pf and powers of a balanced delta load
+
+clc;
+clear;
+
+Z=8+6*%i; // Load
+V=230; // Voltage supply
+
+iR=V/Z;
+theta= atand(imag(iR)/real(iR));
+
+Il= iR*sqrt(3); // Line current
+
+Pa=sqrt(3)*V*abs(Il)*cosd(theta); // Active Power
+Pr=sqrt(3)*V*abs(Il)*sind(theta); // Reactive Power
+
+Pt=sqrt(3)*V*abs(Il); // Total Volt amperes
+
+printf('The line current = %g A \n',abs(Il))
+printf('The power factor = %g lagging \n',cosd(theta))
+printf('The Active Power = %g kW \n',abs(Pa)/1000)
+printf('The Reactive Power = %g kV Ar \n',abs(Pr)/1000)
+printf('The total volt amperes = %g kVA \n',abs(Pt)/1000)
diff --git a/1319/CH3/EX3.6/3_6.sce b/1319/CH3/EX3.6/3_6.sce
new file mode 100644
index 000000000..af27d3316
--- /dev/null
+++ b/1319/CH3/EX3.6/3_6.sce
@@ -0,0 +1,53 @@
+//To find Line currents and star connected resistors for the same power
+
+clc;
+clear;
+
+// Phase Voltages
+Vr=400*(expm(%i*0));
+Vy=400*(expm(%i*-2*%pi/3));
+Vb=400*(expm(%i*2*%pi/3));
+
+Zry=100; // Impedance between Phase R and Phase Y
+Zyb=%i*100;// Impedance between Phase Y and Phase B
+Zbr=-%i*100;// Impedance between Phase B and Phase R
+
+Iry=Vr/Zry;
+Iyb=Vy/Zyb;
+Ibr=Vb/Zbr;
+
+Ir=Iry-Ibr;
+Iy=Iyb-Iry;
+Ib=Ibr-Iyb;
+
+//Phase angles of the line currents in RYB sequence
+tr=atand(imag(Ir)/real(Ir));
+
+if(real(Iy)==0)
+ty=atand((imag(Iy)/abs(imag(Iy)))*%inf);
+else
+ty=atand(imag(Iy)/real(Iy));
+end    
+if(real(Ib)==0)
+tb=atand((imag(Ib)/abs(imag(Ib)))*%inf);
+else
+tb=atand(imag(Ib)/real(Ib));
+end
+
+P=(Iry^2)*Zry; // Power consumed by the circuit ( Arm RY)
+
+Vph=Vr/sqrt(3); // Phase voltage in a star connected system
+
+R=poly([0 1],'R','c');
+
+x=(3*(Vph^2))-(P*R); // Characteristic Eqaution to find R
+
+R=roots(x);
+
+printf('a) The line currents in RYB sequence are : \n')
+printf(' R line = %g/_%g A \n',abs(Ir),tr);
+printf(' Y line = %g/_%g A \n',abs(Iy),ty);
+// Error in text book answer
+printf(' B line = %g/_%g A \n \n',abs(Ib),tb);
+printf('b) The value of resistors to draw same power as in problem statement a) = %g ohms \n',R(1))
+
diff --git a/1319/CH3/EX3.7/3_7.sce b/1319/CH3/EX3.7/3_7.sce
new file mode 100644
index 000000000..84d280087
--- /dev/null
+++ b/1319/CH3/EX3.7/3_7.sce
@@ -0,0 +1,35 @@
+//Reduction in load when one resistor is removed
+
+clc;
+clear;
+
+// Assuming the variables to be eqaul to unit quantities
+
+Vph=1;
+Vl=sqrt(3)*Vph;
+R=1;
+
+// Star connected
+
+Pis=3*(Vph^2)/R; // Initial Power
+
+Pfs=(Vl^2)/(2*R); // Power when one resitor is removed
+
+pers=(Pis-Pfs)*100/Pis; // Percentage decrease in Load
+
+// Mesh connected
+
+Pim=3*(Vl^2)/R; // Initial Power
+
+Pfm=2*(Vl^2)/R; // Power when one resitor is removed
+
+perm=(Pim-Pfm)*100/Pim; // Percentage decrease in Load
+
+printf(' Vl= square root (3) * Vph \n \n')
+printf('a)  Star Connected Power = 3*(Vph^2)/R \n')
+printf('    When one resistor is removed Power = (Vl^2)/2R \n')
+printf('    The percentage reduction in load = %g \n \n',pers)
+
+printf('b)  Mesh Connected Power = 3*(Vl^2)/R \n')
+printf('    When one resitor is removed, Power = 2*(Vl^2)/R \n' )
+printf('    The percentage reduction in load = %g \n',perm)
diff --git a/1319/CH3/EX3.8/3_8.sce b/1319/CH3/EX3.8/3_8.sce
new file mode 100644
index 000000000..90cf4aec1
--- /dev/null
+++ b/1319/CH3/EX3.8/3_8.sce
@@ -0,0 +1,35 @@
+//To measure power by two wattmeter method
+
+clc;
+clear;
+
+pf=0.85 // Power Factor
+
+Po=37.3*(10^3); // Power Output
+
+eff=90/100; // Efficiency
+
+V=500; // Rated Voltage
+
+Pi=Po/eff; // Power Input
+
+phi=acosd(pf); // Power Factor angle
+
+printf('W1 + W2 = %g kW \n',Pi/1000)
+printf('tan(phi) = square root (3)*(W2-W1)/(W2+W1) = %g \n',tand(phi))
+
+x=Pi; // Let x = W1+W2
+
+y= tand(phi)*x/(sqrt(3)); // Let y = W2-W1
+
+printf('W1 + W2 = %g kW \n',x/1000)
+printf('W2 - W1 = %g kW \n',y/1000)
+printf('W2 = %g kW \n',(x+y)/(2*1000))
+printf('W1 = %g kW \n',(x-y)/(2*1000))
+
+
+
+
+
+
+
diff --git a/1319/CH3/EX3.9/3_9.sce b/1319/CH3/EX3.9/3_9.sce
new file mode 100644
index 000000000..bd0aa2516
--- /dev/null
+++ b/1319/CH3/EX3.9/3_9.sce
@@ -0,0 +1,48 @@
+//To find power using two wattmeter method of a circuit with non reactive resistances
+
+clc;
+clear;
+
+V=400; // Line Voltage
+Vph=V/(sqrt(3)); // Magnitude of Phase Voltage
+
+// Phase Voltage in RYB sequnce
+Vr=Vph*(expm(%i*0));
+Vy=Vph*(expm(%i*-2*%pi/3));
+Vb=Vph*(expm(%i*2*%pi/3));
+
+// Resitances of the RYB limbs
+Rr=10;
+Ry=15;
+Rb=20;
+
+// Taking Vr as reference
+// Millain's Theorem
+
+Vs= ((Vr/Rr)+(Vy/Ry)+(Vb/Rb))/((1/Rr)+(1/Ry)+(1/Rb)); // Star point voltage
+
+//Line Currents in RYB sequence
+Ir= (Vr-Vs)/Rr;
+Iy= (Vy-Vs)/Ry;
+Ib= (Vb-Vs)/Rb;
+
+Vry=Vr-Vy;
+Vby=Vb-Vy;
+
+W1= real(Vry*conj(Ir));
+W2= real(Vby*conj(Ib));
+
+Wt= W1+W2; // Total Power
+
+// Note Iy in the text book there is a error in the sign of the real part of Vy
+
+printf('The line currents in RYB sequence are : \n')
+disp(Ir,' R line :')
+printf(' Magnitude = %g A \n',abs(Ir))
+disp(Iy,' Y line :')
+printf(' Magnitude = %g A\n',abs(Iy))
+disp(Ib,' B line :')
+printf(' Magnitude = %g A\n \n',abs(Ib))
+printf(' Total Power = %g kW \n \n',Wt/1000)
+printf(' W1 = %g kW\n',W1/1000)
+printf(' W2 = %g kW\n',W2/1000)