initial commit / add all books

1 files changed, 75 insertions, 0 deletions

diff --git a/3731/CH6/EX6.2/Ex6_2.sce b/3731/CH6/EX6.2/Ex6_2.sce
new file mode 100644
index 000000000..9944263ea
--- /dev/null
+++ b/3731/CH6/EX6.2/Ex6_2.sce
@@ -0,0 +1,75 @@
+//Chapter 6:Induction Motor Drives
+//Example 2
+clc;
+
+//Variable Initialization
+//Ratings of the Delta connected Induction motor
+f=50           //frequency in HZ
+Vl=2200        //line voltage in V
+P=8            //number of poles
+N=735          //rated speed in rpm
+
+//Parameters referred to the stator
+Xr_=0.55        // rotor winding reactance in ohm
+Xs=0.45         // stator winding reactance in ohm
+Rr_=0.1         // resistance of the rotor windings in ohm
+Rs=0.075        // resistance of the stator windings in ohm
+
+//Solution
+Ns=120*f/P     //synchronous speed in rpm
+s=(Ns-N)/Ns    //full load slip
+x=sqrt((Rs+Rr_/s)**2+(Xs+Xr_)**2)   //total impedance
+Ip=(Vl)/x                  //full load phase current
+Il=sqrt(3)*Ip         //full load line current
+Wms=2*%pi*Ns/60        
+Tl=(1/Wms)*(3*Ip**2*Rr_/s) //full load torque
+
+//(i)if the motor is started by star-delta switching
+y=sqrt((Rs+Rr_)**2+(Xs+Xr_)**2)
+Ist=(Vl/sqrt(3))/y                //Maximum line current during starting
+Tst=(1/Wms)*(3*Ist**2*Rr_)             //Starting torque
+ratio1=Tst/Tl                          //ratio of starting torque to full load torque
+z=Rs+sqrt(Rs**2+(Xs+Xr_)**2)
+Tmax=3/(2*Wms)*(Vl/sqrt(3))**2/z  //maximum torque
+ratio2=Tmax/Tl                         //ratio of maximum torque to full load torque
+
+//(ii) If the motor is started using auto transformer
+y=sqrt((Rs+Rr_)**2+(Xs+Xr_)**2)
+Ist1=Vl*sqrt(3)/y         //starting current direct online
+aT=sqrt(2*Il/Ist1)        //transofrmation ratio
+Ilst=2*Il/aT                   //starting motor line current
+Ipst=Ilst/sqrt(3)         //starting motor phase current
+Tst1=(1/Wms)*(3*Ipst**2*Rr_)    //starting torque
+
+//(iii) If motor is started using part winding method
+Rs_=2*Rs
+Xs_=2*Xs
+y=sqrt((Rs_+Rr_)**2+(Xs_+Xr_)**2)
+Ist2=(Vl*sqrt(3))/y      //starting line current 
+Ip=Ist2/sqrt(3)          //starting phase current
+Tst2=(1/Wms)*(3*Ip**2*Rr_)    //starting torque
+
+//(iv) motor is started using series reactors in line
+Rs_=Rs/3  ;  Rr_=Rr_/3
+Xs_=Xs/3  ;  Xr_=Xr_/3
+Il=2*Il        //line current at start
+x=(Vl/sqrt(3))**2/(Il**2)    //x=(Rs_+Rr_)**2+(Xs_+Xr_+Xe)**2
+y=x-(Rs_+Rr_)**2                  //y=(Xs_+Xr_+Xe)**2
+z=sqrt(y)                    //z=(Xs_+Xr_+Xe)
+Xe=z-Xs_-Xr_
+
+
+//Results
+
+mprintf("(i)Maximum value of line current during starting Ist:%d A",Ist)
+mprintf("\nRatio of starting torque to full load torque :%.3f",ratio1)
+mprintf("\nRatio of maximum torque to full load torque :%.2f\n",ratio2)
+mprintf("\n(ii)Transformation ratio aT:%.3f",aT)
+mprintf("\nStarting torque :%d N-m\n",Tst1)
+//Answer for the starting torque in the book is wrong due to accuracy
+
+mprintf("\n(iii)Maximum line current during starting :%d A",Ist2)
+mprintf("\nStarting torque :%d N-m\n",Tst2)
+//Answer for the starting torque in the book is wrong due to accuracy
+
+mprintf("\n(iv)Value of the reactor Xe:%.3f ohm",Xe)