From 7f60ea012dd2524dae921a2a35adbf7ef21f2bb6 Mon Sep 17 00:00:00 2001
From: prashantsinalkar
Date: Tue, 10 Oct 2017 12:27:19 +0530
Subject: initial commit / add all books

---
 3760/CH6/EX6.48/Ex6_48.sce | 55 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 3760/CH6/EX6.48/Ex6_48.sce

(limited to '3760/CH6/EX6.48')

diff --git a/3760/CH6/EX6.48/Ex6_48.sce b/3760/CH6/EX6.48/Ex6_48.sce
new file mode 100644
index 000000000..1c9688d8f
--- /dev/null
+++ b/3760/CH6/EX6.48/Ex6_48.sce
@@ -0,0 +1,55 @@
+clc;
+P=4500; // rated power of induction motor
+V=400; // rated voltage of motor
+f=50; // frequency
+m=3; // number of phases
+// no load test results
+Vo=400; // applied line voltage
+io=4.2; // no load line current
+Po=480; //  power input
+// blocked rotor test
+vb=215; // line voltage
+ib=15; // line current
+pb=1080; // input power
+rs=1.2; // rotor resistance referred to stator per phase
+nt=2; // stator to rotor turns ratio
+pfo=Po/(sqrt(3)*io*Vo); // no load power factor
+pfb=pb/(sqrt(3)*ib*vb); // short circuit power factor
+isc=(V/vb)*(ib*sqrt(3)); // per phase short circuit current
+iop=io/sqrt(3); // per phase no load current
+x=1; // scale 1 A= 1 cm
+// circle diagram is drawn in fig 6.38
+disp('case a');
+// value of maximum torque at starting is not given
+// now we note Bf=4.6 and B'f=1.25 using these values external resistance to be inserted is calculated
+re=(4.6/1.25)*1.2; // external resistance
+printf('External resistance referred to rotor is %f ohms\n',re/nt^2);
+// as per the construction we obtain OB=11.24 which is needed to calculate starting line current
+is=11.24*sqrt(3); 
+printf('Starting current is %f A\n',is);
+// angle OBB'=45.5 which is needed to calculate power factor
+pf=cosd(45.5);
+printf('power factor is %f lagging\n',pf);
+pps=x*V; // per phase power scale
+fp=P/m; // full load power per phase
+disp('case b');
+// now torque is 1.25 times full load torque
+// now we note NK=2.9 and N'K=2.1 using these values external resistance to be inserted is calculated
+re=(2.9/2.1)*1.2; // external resistance
+printf('External resistance referred to rotor is %f ohms\n',re/nt^2);
+// as per the construction we obtain ON=14.35 which is needed to calculate starting line current
+is=14.35*sqrt(3); 
+printf('Starting current is %f A\n',is);
+// angle ONN'=58.3 which is needed to calculate power factor
+pf=cosd(58.3);
+printf('power factor is %f lagging\n',pf);
+disp('case c');
+// we obtain OH=5.35 which is per phase output current
+// thetag=41.3
+opf=cosd(41.3); 
+printf('Operating power factor is %f leading\n',opf);
+po=m*5.35*V*opf; 
+printf('Output power is %f KW\n',po/1000);
+// we note HL=3.95 and Ha=4.90 which is needed for efficiency
+ne=3.95/4.9; 
+printf('Induction generator efficiency is %f percent',ne*100);
-- 
cgit