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+// Calculating the direct and quadrature axis synchronous reactances
+clc;
+disp('Example 11.18, Page No. = 11.52')
+// Given Data
+// 3 phase star connected selient pole alternator
+Q = 2500;// kVA rating
+E = 2400;// Voltage rating (in kV)
+f = 60;// Frequency (in Hz)
+p = 32;// Number of poles
+D = 2.5;// Stator bore (in meter)
+L = 0.44;// Core length (in meter)
+Tph = 224;// Turns per phase
+lg = 10;// Air gap length (in meter)
+Kg = 1.11;// Air gap constraction factor
+Kw = 0.95;// Winding factor
+R = 0.69;// Ratio of pole arc to pole pitch
+A1 = 1.068;// Ratio of amplitude of fundamental of gap flux density to maximum gap density
+Xl = 0.14;// Per unit leakage reactance
+// Calculation of the direct and quadrature axis synchronous reactances
+xm = 7.54*f*Tph*Tph*Kw*Kw*D*L/(p*p*lg*10^(-3)*Kg)*10^(-6);// Magnetic reactance per phase (in ohm)
+Eph =E/3^(1/2);// Voltage per phase
+Iph = Q*1000/(3^(1/2)*E);// Current in each phase
+Xm = Iph*xm/Eph;// Per unit magnetising reactance
+a = R*%pi;// Angle embraced by pole arc (in rad)
+pd = (a+sin(a))/(4*sin(a/2));// Reduction factor for direct axis armature mmf
+Ad1 = pd*A1;// Flux distribution factor for direct axis
+Xad = Ad1*Xm;// Per unit direct axis armature reaction reactance
+Aq1 = ((4*R+1)/5)-(sin(R*%pi)/%pi);// Flux distribution co-efficient for quadrature axis
+Xaq = Aq1*Xm;// Per unit quadrature axis armature reaction reactance
+Xd = Xl+Xad;// Per unit direct axis synchronous reactance
+Xq = Xl+Xaq;// Per unit quadrature axis synchronous reactance
+disp(Xd,'Per unit direct axis synchronous reactance =');
+disp(Xq,'Per unit quadrature axis synchronous reactance =');
+//in book answers are 0.916 and 0.533 respectively.  The answers vary due to round off error