1 files changed, 62 insertions, 0 deletions
diff --git a/3731/CH6/EX6.15/Ex6_15.sce b/3731/CH6/EX6.15/Ex6_15.sce
new file mode 100644
index 000000000..55fb9a151
--- /dev/null
+++ b/3731/CH6/EX6.15/Ex6_15.sce
@@ -0,0 +1,62 @@
+//Chapter 6:Induction Motor Drives
+//Example 15
+clc;
+
+//Variable Initialization
+
+//Ratings of the star connected Induction motor 
+f=50           // frequency in HZ
+Vl=400         //line voltage in V
+P=4            // number of poles
+N=1370         //rated speed
+//Parameters referred to the stator
+Xr_=3.5        // rotor winding reactance in ohm
+Xs=Xr_         // stator winding reactance in ohm
+Rr_=3          // resistance of the rotor windings in ohm
+Rs=2           // resistance of the stator windings in ohm
+Xm=55          // magnetizing reactance in ohm
+
+//Solution
+Wms=4*%pi*f/P
+Ns=120*f/P     //synchronous speed in rpm
+s=(Ns-N)/Ns    //full load slip
+x=%i*Xm*(Rr_/s+%i*Xr_)
+y=Rr_/s+%i*(Xr_+Xm)
+Z=Rs+%i*Xs+x/y        //total motor impedance
+Isf=(Vl/sqrt(3))/abs(Z)                  //full load stator current
+Irf_=Isf*(%i*Xm)/(Rr_/s+%i*(Xr_+Xm))          //full load rotor current
+Tf=(3/Wms)*abs(Irf_)**2*Rr_/s                 //full load  torque
+N1=Ns-N        //full load slip speed
+//(i) When the motor is operating at 30Hz
+f1=30          //given frequency in Hz
+//At rated slep speedvalue of torque and stator current is same as the rated value
+T=Tf 
+Is=abs(Isf)    
+Ns1=f1/f*Ns    //synchronous at f1=30Hz
+N2=Ns1-N1      //required motor speed at 30Hz
+
+//(ii)At a speed of 1200 rpm
+N3=1200       //speed in rpm
+Ns1=N3+N1     //required synchronous speed
+f1=Ns1/Ns*f   //required frequency at N2=1200rpm
+
+//(iii)When speed-torque curves are assumed to be straight lines at 30Hz at half the rated motor torque
+f2=30          //frequency in Hz
+N1_=N1/2       //slip at half the rated torque
+Ns1=f2/f*Ns    //synchronous at f1=30Hz
+N4=Ns1-N1_     //required motor speed
+
+//(iv) When the motor is operating at 45hz  and braking torque is equal to rated torque
+f3=45          //given frequency in Hz
+N1_=-N1        //slip speed when braking at rated torque
+Ns1=f3/f*Ns    //synchronous at f1=45Hz
+N5=Ns1-N1_     //required motor speed
+
+
+//results
+mprintf("(i)At 30Hz the required value of Torque is T:%.2f N-m",T)
+mprintf("\nStator current is Is:%.4f A",Is)
+mprintf("\nMotor speed is :%d rpm",N2)
+mprintf("\n(ii)Required inverter frequency is :%.2f Hz",f1)
+mprintf("\n(iii)Required motor speed at 30Hz is:%d rpm",N4)
+mprintf("\n(iv)Required motor speed at 45Hz is:%d rpm",N5)