// Electric Machinery and Transformers // Irving L kosow // Prentice Hall of India // 2nd editiom // Chapter 13: RATINGS,SELECTION,AND MAINTENANCE OF ELECTRIC MACHINERY // Example 13-10 clear; clc; close; // Clear the work space and console. // Given data // single phase alternator V_orig = 500 ; // Rated voltage of the alternator in volt kVA_orig = 20 ; // Rated power of the alternator in kVA I = 40 ; // Rated current of the alternator in A R = 2 ; // Armature resistance in ohm X = 15 ; // Armature reactance in ohm V_new = 5000 ; // New voltage of the alternator in volt kVA_new = 100 ; // New power of the alternator in kVA // Calculated armature impedance from Ex.13-9c Z_pu_orig = 1.211 ; // original per-unit value of armature impedance in p.u // Calculation Z_pu_new = Z_pu_orig * (kVA_new/kVA_orig) * (V_orig/V_new)^2 ; // new per-unit value of armature impedance in p.u // Display the results disp("Example 13-10 Solution : "); printf(" \n New per-unit value of armature impedance\n Z_pu(new) = %.5f p.u",Z_pu_new);