// 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 1: INDUSTRIAL APPLICATIONS OF ELECTRIC MOTORS // EXAMPLE : 1.2 : // Page number 680 clear ; clc ; close ; // Clear the work space and console // Given data I_sc = 6.0 // Short circuit current = 6 times full load current s_fl = 5.0 // Full load slip(%) tap = 60.0 // Auto-tranformer tapping(%) // Calculations // Case(a) I_s_fl_a = I_sc/3.0 // I_s/I_fl T_s_fl_a = I_s_fl_a**2*s_fl/100 // Starting torque in terms of full-load torque with star-delta starter // Case(b) I_s_fl_b = tap/100*I_sc // I_s/I_fl T_s_fl_b = I_s_fl_b**2*s_fl/100 // Starting torque in terms of full-load torque with auto-transformer starter // Results disp("PART IV - EXAMPLE : 1.2 : SOLUTION :-") printf("\nCase(a): Starting torque in terms of full-load torque with star-delta starter, I_s/I_fl = %.1f ", T_s_fl_a) printf("\nCase(b): Starting torque in terms of full-load torque with auto-transformer starter, I_s/I_fl = %.3f ", T_s_fl_b)