// ELECTRIC POWER TRANSMISSION SYSTEM ENGINEERING ANALYSIS AND DESIGN // TURAN GONEN // CRC PRESS // SECOND EDITION // CHAPTER : 6 : DIRECT-CURRENT POWER TRANSMISSION // EXAMPLE : 6.7 : clear ; clc ; close ; // Clear the work space and console // GIVEN DATA X_C = 12.649731 ; // commutating reactance when 2 breakers are open alpha = 0 ; I_d = 1600 ; // DC current in A E_LN = 53.4188 * 10^3 ; // Wye-side rating in V V_d0 = 125 * 10^3 ; // voltage rating of bridge rectifier in V // CALCULATIONS // For case (a) E_m = sqrt(2) * E_LN ; u = acosd(1 - (2 * X_C * I_d)/(sqrt(3) * E_m)) ; // overlap angle u = δ // For case (b) // since rectifier operates in first mode i.e doesn't operate in second mode R_C = (3/%pi) * X_C ; V_dr = ( V_d0 * cosd(alpha) ) - (R_C*I_d) ; // dc voltage of rectifier in V // DISPLAY RESULTS disp("EXAMPLE : 6.7 : SOLUTION :-") ; printf("\n (a) u = %.1f degree \n",u) ; printf("\n since u < 60 degree . The rectifier operates at FIRST mode , the normal operating mode \n") ; printf("\n (b) When dc current is 1600 A , V_dr = %.2f V \n",V_dr) ;