// A Texbook on POWER SYSTEM ENGINEERING // A.Chakrabarti, M.L.Soni, P.V.Gupta, U.S.Bhatnagar // DHANPAT RAI & Co. // SECOND EDITION // PART IV : UTILIZATION AND TRACTION // CHAPTER 6: MOTORS FOR ELECTRIC TRACTION // EXAMPLE : 6.5 : // Page number 792-793 clear ; clc ; close ; // Clear the work space and console // Given data I_1 = 100.0 // Current(A) N_1 = 71.0 // Speed(kmph) F_t1 = 2225.0 // Tractive effort(N) I_2 = 150.0 // Current(A) N_2 = 57.0 // Speed(kmph) F_t2 = 6675.0 // Tractive effort(N) I_3 = 200.0 // Current(A) N_3 = 50.0 // Speed(kmph) F_t3 = 11600.0 // Tractive effort(N) I_4 = 250.0 // Current(A) N_4 = 45.0 // Speed(kmph) F_t4 = 17350.0 // Tractive effort(N) I_5 = 300.0 // Current(A) N_5 = 42.0 // Speed(kmph) F_t5 = 23200.0 // Tractive effort(N) D_A = 101.6 // Size of wheels(cm) ratio_gear = 72.0/23 // Gear ratio D_B = 106.7 // Size of wheels(cm) ratio_gear_new = 75.0/20 // Gear ratio // Calculations N_B = ratio_gear*D_B/(ratio_gear_new*D_A) // Speed in terms of V(kmph) F_tB = D_A*ratio_gear_new/(ratio_gear*D_B) // Tractive effort in terms of F_tA(N) N_B1 = N_B*N_1 // Speed(kmph) F_tB1 = F_tB*F_t1 // Tractive effort(N) N_B2 = N_B*N_2 // Speed(kmph) F_tB2 = F_tB*F_t2 // Tractive effort(N) N_B3 = N_B*N_3 // Speed(kmph) F_tB3 = F_tB*F_t3 // Tractive effort(N) N_B4 = N_B*N_4 // Speed(kmph) F_tB4 = F_tB*F_t4 // Tractive effort(N) N_B5 = N_B*N_5 // Speed(kmph) F_tB5 = F_tB*F_t5 // Tractive effort(N) // Results disp("PART IV - EXAMPLE : 6.5 : SOLUTION :-") printf("\nNew characteristics of motor") printf("\n_______________________________________") printf("\n Current(A) : Speed(kmph) : F_t(N)") printf("\n_______________________________________") printf("\n %.f : %.1f : %.f ", I_1,N_B1,F_tB1) printf("\n %.f : %.1f : %.f ", I_2,N_B2,F_tB2) printf("\n %.f : %.1f : %.f ", I_3,N_B3,F_tB3) printf("\n %.f : %.1f : %.f ", I_4,N_B4,F_tB4) printf("\n %.f : %.1f : %.f ", I_5,N_B5,F_tB5) printf("\n_______________________________________\n") printf("\nNOTE: Changes in the obtained answer from that of textbook is due to more precision here")