Question

USE MATLAB. PROVIDE MATLAB CODE FOR CALCULATIONS AND GRAPHS!

A salient-pole synchronous generator with saturated synchronous reactances Xd = 0.78 per unit and Xq = 0.63 per unit is connected to a rated-voltage infinite bus through an external impedance Xbus = 0.09 per unit.

a) Assuming the generator to be supplying 0.25 per unit rated real power, add a plot of the per-unit armature current as a function of field excitation as the field current is varied in the range for which the per-unit armature current is less than 1.0 per unit. Repeat for generator output powers of 0.50 and 0.75 per unit and add plots on the same axis.

HINT: The final result will be a plot of V-curves for this generator in this configuration.

Answer 1

MATLAB CODE:

Ea=0.28:0.1:1.72;
ia=(1-Ea)/0.72i;
plot(Ea,abs(ia))
xlabel('E_a')
ylabel('i_a')

OUTPUT: