1 files changed, 87 insertions, 0 deletions
diff --git a/3640/CH4/EX4.3/EX4_3.sce b/3640/CH4/EX4.3/EX4_3.sce
new file mode 100644
index 000000000..93e14b03a
--- /dev/null
+++ b/3640/CH4/EX4.3/EX4_3.sce
@@ -0,0 +1,87 @@
+clc
+//code uses userdefined function complexstring
+function s=complexstring(a)
+    
+    
+    if imag(a)>=0 then
+        s=sprintf('%g+%gi',real(a),imag(a))
+    else
+        s=sprintf('%g%gi',real(a),imag(a))
+        
+    end
+    funcprot(0)
+endfunction
+
+//induction machine parameters in ohms
+r1=0.39 //primary resistance
+r2=0.14 //secondary resistance
+x1=0.35//primary reactance
+x2=0.35//secondary reactance
+Xm=16//manetizing reactance
+VL=220 //supply volatge in volts
+f=60 //frequency in Hz
+//part a
+p=4 //no of poles
+ns=(120*f)/p 
+mprintf("ns=%drev/min\n",ns)
+n=1746 //runnimg speed of motor in rev/min
+s=(ns-n)/ns
+mprintf("s=%f\n",s)
+z2=(r2/s)+(%i*x2)//ans may vary due to roundoff error
+disp('Z2='+complexstring(z2)+'Ω')
+mprintf("Z2=%fohm having a phase angle of %f degrees\n",abs(z2),(acos(real(z2)/abs(z2)))*180/%pi)
+Zf=(%i*Xm*z2)/(z2+(%i*Xm))//ans may vary due to roundoff error
+disp('Zf='+complexstring(Zf)+'Ω')
+mprintf("Zf=%fohms having a phase angle of %f degrees\n",abs(Zf),(acos(real(Zf)/abs(Zf)))*180/%pi)
+Rf=real(Zf)//ans may vary due to roundoff error
+mprintf("Rf=%fΩ\n",Rf)
+Zin=r1+(%i*x1)+Zf//ans may vary due to roundoff error
+disp('Zin=r1+jx1+Zf='+complexstring(Zin)+'Ω')
+mprintf("Zin=%fohms having a phase angle of %f degrees\n",abs(Zin),(acos(real(Zin)/abs(Zin)))*180/%pi)
+Powerfctor=real(Zin)/abs(Zin)//ans may vary due to roundoff error
+mprintf("Power facto=%f\n",Powerfctor)
+I1=VL/(sqrt(3)*abs(Zin))
+mprintf("|I1|=%fA\n",I1)//ans may vary due to roundoff error
+Pin=sqrt(3)*I1*VL*Powerfctor
+mprintf("Pin=%fW\n",Pin)//ans in the textbook is wrong
+Pg=3*I1*I1*Rf
+mprintf("Pg=%fW\n",Pg)//ans in the textbook is wrong
+DMP=(1-s)*Pg
+mprintf("Developed power=(1-s)Pg=%fW\n",DMP)//ans in the textbook is wrong
+Prot=s*Pg //rotor copper losses
+Pout=DMP-Prot//ans in the textbook is wrong
+mprintf("Output power=%fW\n",Pout)
+mprintf("Output horsepower=%f\n",Pout/746)//ans may vary due to roundoff error,1 hp=746 watts
+mprintf("Developed torque=%flb-ft\n",7.04*(Pg/ns))//ans may vary due to roundoff error,1 N-m=7.04 lb-ft ot torque
+n=(1-s)*ns//ans may vary due to roundoff error
+mprintf("Output torque=%flb-ft\n",7.04*(Pout/n))
+mprintf("Efficiency=%f\n",Pout/Pin)
+//part b
+s=1 //machine at stanstill
+z2=r2+(%i*x2)//ans may vary due to roundoff error
+disp('Z2='+complexstring(z2)+'Ω')
+mprintf("Z2=%fohm having a phase angle of %f degrees\n",abs(z2),(acos(real(z2)/abs(z2)))*180/%pi)
+Zf=(%i*Xm*z2)/(z2+(%i*Xm))//ans may vary due to roundoff error
+disp('Zf='+complexstring(Zf)+'Ω')
+mprintf("Zf=%fohms having a phase angle of %f degrees\n",abs(Zf),(acos(real(Zf)/abs(Zf)))*180/%pi)
+Zin=r1+(%i*x1)+Zf//ans may vary due to roundoff error
+disp('Zin='+complexstring(Zin)+'Ω')
+mprintf("Zin=%fohms having a phase angle of %f degrees\n",abs(Zin),(acos(real(Zin)/abs(Zin)))*180/%pi)
+I1=VL/(sqrt(3)*abs(Zin))//ans may vary due to roundoff error
+Rf=real(Zf)
+mprintf("Starting current=%fA\n",I1)
+Pg=3*I1*I1*Rf
+mprintf("Pg=%fW\n",Pg)//ans in the textbook is wrong
+mprintf("τd=7.04*(Pg/ns)=%flb-ft\n",7.04*(Pg/ns))//ans may vary due to roundoff error,1 N-M=7.04 lb-ft of torque
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