1 files changed, 28 insertions, 0 deletions
diff --git a/3760/CH6/EX6.64/Ex6_64.sce b/3760/CH6/EX6.64/Ex6_64.sce
new file mode 100644
index 000000000..d3469b9a8
--- /dev/null
+++ b/3760/CH6/EX6.64/Ex6_64.sce
@@ -0,0 +1,28 @@
+clc;
+v=3300; // rated voltage of induction motor
+p=6; // number of poles
+f=50; // frequency
+t=3.2; // stator to rotor turns
+r=0.1; // rotor resistance
+x=1; // rotor leakage reactance
+R=t^2*r; // rotor resistance referred to stator
+X=t^2*x; // rotor reactance referred to stator
+ws=(4*%pi*f)/p; // synchronous speed
+disp('case a');
+is=(v/sqrt(3))/(sqrt(R^2+X^2)); 
+printf('Starting current at rated voltage is %f A\n',is);
+Ts=(3*is^2*R)/ws; 
+printf('Starting torque at rated voltage is %f Nm\n',Ts);
+disp('case b');
+is=50; // starting current
+// is=Vp/(sqrt((R+rex)^2+X^2) where rex is external resistance and Vp is phase voltage
+// solving above equation we get a quadratic equation in rex whose terms are
+t1=1;
+t2=2*R; 
+t3=(R^2+X^2)-((v/sqrt(3))/is)^2;
+p=[ t1 t2 t3 ];
+rex=roots(p);  
+printf('External resistance referred to rotor is %f ohms\n',rex(2)/t^2);
+Ts=(3*is^2*(R+rex(2)))/ws; 
+printf('Starting torque under new condition is %f Nm\n',Ts);
+