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+// Electric Machinery and Transformers
+// Irving L kosow
+// Prentice Hall of India
+// 2nd editiom
+
+// Chapter 12: POWER,ENERGY,AND EFFICIENCY RELATIONS OF DC AND AC DYNAMOS
+// Example 12-16
+
+clear; clc; close; // Clear the work space and console.
+
+// Given data
+// code letter = J
+P = 6 ; // Number of poles
+S_r = 1176 ; // rotor speed in rpm
+V = 220 ; // Rated voltage of SCIM in volt
+f = 60 ; // Frequency in Hz
+hp_SCIM = 7.5 ; // Power rating of SCIM in hp
+
+R_ap = 0.3 ; // armature resistance in ohm/phase
+R_r = 0.144 ; // rotor resistance in ohm/phase
+jX_m = 13.5 ; // reactance in ohm/phase
+jX_s = 0.5 ; // synchronous reactance in ohm/phase
+jX_lr = 0.2 ; // Locked rotor reactance in ohm/phase
+P_r = 300 ; // Rotational losses in W
+
+disp("Example 12-16 : ");
+// Calculations
+S = (120*f/P); // Speed of synchronous magnetic field in rpm
+// case a
+s = (S-S_r)/S ; // Slip
+
+R_r_by_s = R_r / s ;
+
+// case b
+printf(" \n From fig.12-11 , using the format method of mesh analysis,we may write");
+printf(" \n the array by inspection :\n ");
+printf(" \n_______________________________________________");
+printf(" \n \t I_1 \t I_2 \t\t V ");
+printf(" \n_______________________________________________");
+printf(" \n\t (0.3+j14) -(0+j13.5) \t(127+j0)");
+printf(" \n\t-(0+j13.5) (7.2+j13.7) \t 0");
+printf(" \n_______________________________________________\n");
+
+A = [ (0.3 + %i*14) -%i*13.5 ; (-%i*13.5) (7.2 + %i*13.7) ]; // Matrix containing above mesh eqns array
+delta = det(A); // Determinant of A
+
+// case b : Stator armature current I_p in A
+I_p = det( [ (127+%i*0) (-%i*13.5) ; 0 (7.2 + %i*13.7) ] ) / delta ;
+I_p_m = abs(I_p);//I_p_m=magnitude of I_p in A
+I_p_a = atan(imag(I_p) /real(I_p))*180/%pi;//I_p_a=phase angle of I_p in degrees
+I_1 = I_p ; // Stator armature current in A
+
+// case c : Rotor current I_r per phase in A
+I_r = det( [ (0.3 + %i*14) (127+%i*0) ; (-%i*13.5) 0 ] ) / delta ;
+I_r_m = abs(I_r);//I_r_m=magnitude of I_r in A
+I_r_a = atan(imag(I_r) /real(I_r))*180/%pi;//I_r_a=phase angle of I_r in degrees
+
+// case d
+theta = I_p_a ; // Motor PF angle in degrees
+cos_theta = cosd(theta); // Motor PF
+
+// case e
+I_p = I_p_m ; // Stator armature current in A
+V_p = V / sqrt(3); // Phase voltage in volt
+SPI = V_p * I_p * cos_theta ; // Stator Power Input in W
+
+// case f
+SCL = (I_p)^2 * R_ap ; // Stator Copper Loss in W
+
+// case g
+// Subscripts 1 and 2 for RPI indicates two methods of calculating RPI
+RPI_1 = SPI - SCL ; // Rotor Power Input in W
+RPI_2 = (I_r_m)^2 * (R_r/s); // Rotor Power Input in W
+RPI =RPI_1 ;
+
+// case h
+RCL = s*(RPI); // Rotor copper losses in W
+
+// case i
+// Subscripts 1 , 2 and 3 for RPD indicates three methods of calculating RPD
+RPD_1 = RPI - RCL ; // Rotor Power Developed in W
+RPD_2 = RPI * ( 1 - s ); // Rotor Power Developed in W
+RPD = RPD_1 ;
+
+// case j
+RPO = 3*RPD - P_r ; // Rotor Power Developed in W
+
+// case k
+P_to = RPO ; // Total rotor power in W
+T_o = (7.04*P_to)/S_r ; // Total 3-phase torque in lb-ft
+
+// case l
+hp = P_to / 746 ; // Output horsepower
+
+// case m
+P_in = 3*SPI ; // Input power to stator in W
+P_o = RPO ; // Output power in W
+eta = P_o / P_in * 100 ; // Motor efficiency at rated load
+
+// Display the results
+disp("Solution : ");
+printf(" \n a: s = %.2f \n R_r/s = %.1f Ω \n",s,R_r_by_s );
+
+printf(" \n Determinant Δ = ");disp(delta);
+
+printf(" \n b: Stator armature current :\n I_p in A = ");disp(I_1);
+printf(" \n I_p = I_1 = %.2f <%.2f A \n ",I_p_m , I_p_a );
+
+printf(" \n c: Rotor current per phase :\n I_r in A = ");disp(I_r);
+printf(" \n I_r = I_2 = %.3f <%.2f A \n ",I_r_m , I_r_a );
+
+printf(" \n d: Motor PF :\n cosӨ = %.4f \n",cos_theta);
+
+printf(" \n e: Stator Power Input :\n SPI = %d W \n",SPI);
+
+printf(" \n f: Stator Copper Loss :\n SCL = %.1f W \n",SCL);
+
+printf(" \n g: Rotor Power Input :\n RPI = %.1f W(method 1) ", RPI_1);
+printf(" \n RPI = %.1f W (method 2)\n",RPI_2);
+
+printf(" \n h: Rotor copper loss :\n RCL = %.1f W\n",RCL);
+
+printf(" \n i: Rotor Power Developed :\n RPD = %.1f W \n",RPD_1);
+
+printf(" \n RPD = %.1f W \n ",RPD_2);
+
+printf(" \n j: Total 3-phase rotor power:\n RPO = %f W \n",RPO);
+
+printf(" \n k: Total output torque developed :\n T_o = %.2f lb-ft\n",T_o);
+
+printf(" \n l: Output horsepower : \n hp = %.2f hp (rated 7.5 hp)\n",hp);
+
+printf(" \n m: Motor efficiency at rated load :\n η = %.2f percent \n",eta);
+
+printf(" \n n: See Fig.12-12");