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+//Chapter 7:Synchronous Motor and Brushless DC Motor Drives
+//Example 2
+clc;
+
+//Variable Initialization
+
+//Ratings of the synchronous motor is same as that of Example-7.1
+Pm1=500*1000   // power rating in W
+f=50           // frequency in HZ
+Vl=3.3*1000    // line voltage in V
+pf=0.8         // power factor lagging
+P=4            // number of poles
+I=10           // field current in A
+Xs=15          // reactance of the windings in ohm
+Rs=0           // resistance of the windings in ohm
+Pm=Pm1/2       // power at half the rated torque when the losses are neglected
+
+//Solution
+Wms=50*%pi     // synchronous speed in rad/sec
+V=Vl/sqrt(3)  // phase voltage
+Is=Pm1/(sqrt(3)*Vl*pf)  //rated current
+rad=acos(pf)
+
+Is=Is * (cos(-rad) + sin(-rad)*%i) //rated current in vector form
+V=V * (cos(0) + sin(0))       //rated phase voltage in rectangular form 
+E=V-Is*%i*Xs                 //back emf
+
+//(i) at rated current and unity power factor
+E1=V-abs(Is)*%i*Xs
+delta=phasemag(E1)       //phase angle of E1
+nd=delta*%pi/180
+Pm=3*abs(V)*abs(E1)*sin(nd)/Xs   //mechanical power developed
+T=Pm/Wms                //braking torque
+If=abs(E1)/abs(E)*I     //field current
+
+//(ii) at field current of 15A and 500kW output
+If1=15           //field current
+Pm=-500*1000    //output power 
+E2=If1/I*abs(E)
+sin_delta=Pm*Xs/(3*abs(V)*abs(E2))  
+delta=asin(sin_delta)               //angle delta
+Is=((E2*(cos(abs(delta))+sin(abs(delta))*%i))-V)/(%i*Xs) //armature current
+Isn=phasemag(Is)
+x=(Isn)*%pi/180        //phase angle of Is
+power_factor=cos(x) //power factor
+
+
+//Results
+mprintf("i)Braking torque :%.1f N-m",T)
+mprintf("\nField current:%.2f A",If)
+mprintf("\nii)Armature current :%.2f %.2f ° A",abs(Is),Isn)
+mprintf("\nPower factor:%.3f lagging",power_factor)
+//Note :There is a slight difference in the answers