//Chapter 23, Problem 10 clc; nr = 24; // in rev/sec p = 4/2; // no. of pole pairs R2 = 0.35; // in Ohms X2 = 3.5; // in Ohms V = 415; // in Volts tr = 0.85; // turn ratio N2/N1 f = 50 ; // in Hz Pl = 770; // in Watt m = 3; // no. of phases //ns is the synchronous speed, f is the frequency in hertz of the supply to the stator and p is the number of pairs of poles. ns = f/p //The slip, s s = ((ns - nr)/ns)*100 // in percent //Phase voltage, E1 = V/(3^0.5) E1 = V/(3^0.5) //Full load torque T = [m*(tr^2)/(2*%pi*ns)]*[(s/100)*E1*E1*R2/(R2*R2 + (X2*(s/100))^2)] //Output power, including friction losses Pm = 2*%pi*nr*T //power output Po = Pm - Pl //Maximum torque occurs when R2 = Xr = 0.35 ohm //Slip sm = R2/X2 //maximum torque, Tm Tm = [m*(tr^2)/(2*%pi*ns)]*[sm*E1*E1*R2/(R2*R2 + (X2*sm)^2)] //speed at which maximum torque occurs nrm = ns*(1 - sm) nrmrpm = nrm*60 //At the start, i.e., at standstill, slip, s=1 ss = 1 //starting torque Ts = [m*(tr^2)/(2*%pi*ns)]*[ss*E1*E1*R2/(R2*R2 + (X2*ss)^2)] printf("\n\n(a)Synchronous speed is %.0f rev/sec",ns) printf("\n\n(b)Slip is %.0f percent",s) printf("\n\n(c)Full load torque is %.2f Nm",T) printf("\n\n(d)power output is %.2E W",Po) printf("\n\n(e)maximum torque is %.2f Nm",Tm) printf("\n\n(f)speed at which maximum torque occurs is %.0frev/min",nrmrpm) printf("\n\n(g)starting torque is %.2f Nm",Ts)