6 files changed, 162 insertions, 0 deletions
diff --git a/1319/CH7/EX7.1/7_1.sce b/1319/CH7/EX7.1/7_1.sce
new file mode 100644
index 000000000..68b3e0b17
--- /dev/null
+++ b/1319/CH7/EX7.1/7_1.sce
@@ -0,0 +1,19 @@
+//Power delivered to 3 phase synchronous motor 
+
+clc;
+clear;
+
+Vl=2300;
+Il=8.8;
+pf=0.8// Lead Power Factor
+theta=acosd(pf)
+
+P=sqrt(3)*Vl*Il; // Power delivered by the pump
+
+I=P/(sqrt(3)*Vl*pf); // Increase in Current
+
+Pr=sqrt(3)*Vl*I*sind(theta); // kVAr supplied
+
+printf('The Power delivered by the pump = %g kW \n',P/1000)
+printf('The Rheostat should be decreased such that the ammeter reads %g A \n',I)
+printf('The kVAr supplied by the motor = %g kVAr',Pr/1000)
diff --git a/1319/CH7/EX7.2/7_2.sce b/1319/CH7/EX7.2/7_2.sce
new file mode 100644
index 000000000..8f65ab20c
--- /dev/null
+++ b/1319/CH7/EX7.2/7_2.sce
@@ -0,0 +1,44 @@
+//New plant pf and percent decrease in line current
+
+clc;
+clear;
+
+Pmp=5000*(10^3); // Electrical load
+pfmp=0.8; // Lag
+
+Pim=500*735;// One horse power is 735W
+Effim=96/100; // Efficiency of the motor
+pfim=0.9; // Lag
+pfsm=0.8; // Lead
+
+Pime=Pim/Effim;// Effective power delivered by the induction motor
+
+deff('x=com(y,z)','x=y+(%i*y*tand(acosd(z)))')// Function to find the complex powers
+
+//Complex Powers
+Pcmp=com(Pmp,pfmp); // Manufacturing Plant Load
+Pcim=com(Pime,pfim);// Induction Motor
+Pcsm=com(Pime,-pfsm);// Synchronous Machine, Minus Sign indicates Lead
+
+Pr=Pcmp-Pcim+Pcsm; // Plant Requirement after replacement
+
+pfar=real(Pr)/abs(Pr); // New Power Factor of the plant
+
+Pnp=abs(Pr);
+
+Vl=poly([0 1],'Vl','c');
+
+Io=Pmp/(pfmp*sqrt(3)*Vl);
+In=Pnp/(sqrt(3)*Vl); // Improved Factor Value =1;
+
+red=(Io-In)*100/Io; // Reduction percent in fractions
+
+redeq=Vl-red;// Reduction percent in decimal characteristic equation 
+
+redper=roots(redeq(2));
+
+printf('The New Power Factor of the plant = %g lag \n',pfar )
+printf('The Percentage decrease in line current that will result in improved p.f = %g percent \n',redper)
+
+
+
diff --git a/1319/CH7/EX7.3/7_3.sce b/1319/CH7/EX7.3/7_3.sce
new file mode 100644
index 000000000..1fb843214
--- /dev/null
+++ b/1319/CH7/EX7.3/7_3.sce
@@ -0,0 +1,14 @@
+//kVAr rating of a synchronous condenser
+
+clc;
+clear;
+
+P=5000*(10^3); // Power delivered to the load
+pfo=0.8;// Original Power Factor
+pfn=0.9;// New Power Factor
+Pcomo=P+%i*(P*tand(acosd(pfo)));//Original Complex Power
+Pcomn=P+%i*(P*tand(acosd(pfn)));//New Complex Power
+
+Psc=abs(imag(Pcomo-Pcomn)); // Difference in kVAr;
+
+printf('The kVAr rating of the synchronous condenser to correct the original p.f to 0.9 = %g kVAr \n',Psc/1000)
diff --git a/1319/CH7/EX7.4/7_4.sce b/1319/CH7/EX7.4/7_4.sce
new file mode 100644
index 000000000..1049d83c4
--- /dev/null
+++ b/1319/CH7/EX7.4/7_4.sce
@@ -0,0 +1,34 @@
+//Calculate E per phase and Current and pf
+
+clc;
+clear;
+
+V=2300;
+delta=20;
+Pd=255*735.5; // Power delivered converted to W from HP
+Xs=10;
+eff=90/100; //Efficiency
+
+P=Pd/eff;
+
+E=poly([0 1],'E','c');
+
+x=(sqrt(3)*E*V*sind(delta))-(P*Xs); // Characteristic Equation to find E
+
+E=roots(x);
+
+Vph=V/(sqrt(3));// Phase Voltage
+
+I=((Vph*expm(%i*0))-(E*expm(%i*(-%pi/9))))/(%i*Xs);// Current Eqaution
+
+[Im,phi]=polar(I); // Angle in radians and magnitude
+
+phid=(abs(phi)/%pi)*180;// Power Factor Angle in Degrees
+
+pf=cosd(phid);
+
+// High Precision Answers
+printf('a) E per phase = %g V \n',E)
+disp('amperes',I,'b) I =')
+printf('\n c) p.f = %g lead \n',pf)
+
diff --git a/1319/CH7/EX7.5/7_5.sce b/1319/CH7/EX7.5/7_5.sce
new file mode 100644
index 000000000..eb839751a
--- /dev/null
+++ b/1319/CH7/EX7.5/7_5.sce
@@ -0,0 +1,34 @@
+//Voltage Regulation of a 3 Phase alternator
+
+clc;
+clear;
+
+Ra=0.093;
+Xs=8.5;
+Z=(Ra+(%i*Xs)); // Total Impedance
+
+P=1500*(10^3); // Power delivered at full load
+V=6.6*(10^3); // Voltage per line
+Vph=V/(sqrt(3)); // Voltage per phase
+
+Il=P/(sqrt(3)*V); // Full Load Current
+
+
+// Taking voltage as reference
+//Power Angles
+theta1=-acos(0.8); // Negative Sign as It is lagging
+theta2=acos(0.8); 
+
+deff('a=pot(b)','a=Vph+((Il*expm(%i*b))*Z)')// Function to find out the output phase voltage
+
+E1=pot(theta1);
+E2=pot(theta2);
+
+deff('y=vg(x)','y=(abs(x)-Vph)*100/Vph') // Function to find out the voltage regulation using the formuala
+
+Vreg1=vg(E1);
+Vreg2=vg(E2);
+
+printf('The Voltage regulation of a 3-Phase 1500 kVA, 6.6 kV alternator at \n')
+printf('i) 0.8 lag = %g percent \n',Vreg1)
+printf('ii) 0.8 lead = %g percent \n',Vreg2)
diff --git a/1319/CH7/EX7.6/7_6.sce b/1319/CH7/EX7.6/7_6.sce
new file mode 100644
index 000000000..5a0d89d3a
--- /dev/null
+++ b/1319/CH7/EX7.6/7_6.sce
@@ -0,0 +1,17 @@
+// Internal Voltage drop in an alternator
+
+clc;
+clear;
+
+If=10;
+Voc=900; // Open Circuit Voltage
+
+Isc=150; // Short Circuit Current
+
+Zs=Voc/Isc;
+
+I=60; // Load current
+
+Vd=I*Zs; // Internal Voltage Drop
+
+printf('The internal voltage drop with a load current of 60 A = %g V \n',Vd)