1 files changed, 49 insertions, 0 deletions
diff --git a/3640/CH2/EX2.5/Ex2_5.sce b/3640/CH2/EX2.5/Ex2_5.sce
new file mode 100644
index 000000000..d73ae2672
--- /dev/null
+++ b/3640/CH2/EX2.5/Ex2_5.sce
@@ -0,0 +1,49 @@
+clc
+//the following code contains userdefined fucntion 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
+Load=5000 //load of the plant in kW
+pf1=0.8 //power factor of load(lagging)
+pf2=0.9 //power factor of induction motor
+pf3=0.8 //power factor of synchronous motor
+Hp=500 //rating of induction motor to be replaced in hp
+Pout=0.746*Hp //output power of induction motor in kW
+Eta=0.96 //efficiency of the induction motor equal to η in textbook
+Sp=Load+(Load*tan(acos(pf1)))*%i //original complex power of load in kVA
+disp('Sp=' + complexstring(Sp)+'kVA')
+Pin=Pout/Eta //input power in kW
+mprintf("Pin=%fkW\n",Pin)//complex power of induction motor //the ans may vary due to round off error
+Sm=Pin+(Pin*tan(acos(pf2)))*%i
+disp('Sm='+complexstring(Sm)+'kVA')//the ans may vary due to round off error //complex power of induction motor
+mprintf("\n")
+Ss=Pin-(Pin*tan(acos(pf3)))*%i
+disp('Ss='+complexstring(Ss)+'kVA')//complex power of synchronous machine //the ans may vary due to round off error
+mprintf("\n")
+Qm=(Pin*tan(acos(pf2)))*%i//reactive power of induction motor in kVAR
+Qs=(-1*(Pin*tan(acos(pf3)))*%i)//reactive power of synchronous motor in kVAR
+Sp1=Sp-Qm+Qs
+disp('Sp1='+complexstring(Sp1)+'kVA')//new plant requirement,equal to Sp` in textbook
+mprintf("\n")
+pha=acos(real(Sp1)/abs(Sp1)) //phase angle of Sp1 in radians
+mprintf("New power factor=%f\n",cos(pha))//new power factor //the ans may vary due to round off error
+invl=abs(Sp)//initial value of complex power in kVA
+fnvl=abs(Sp1) //final value of complex power in kVA 
+mprintf("Percent reduction=%f%c\n",(((invl-fnvl)/invl)*100),'%')//the ans may vary due to round off error
+
+
+
+
+
+
+
+
+
+