Problem 104-3    Source:  Problem prepared by the website author.

A shunt generator of 80 kw and voltage 380 volts, has an armature resistance R_A = 0.08 Ω and field strength equal to R_F = 47.5 Ω . If the generator operates at rated voltage, the following is required:

a) Calculate the armature current;

b) Calculate the induced voltage at full load;

c) Calculate the losses in the armature winding.

Solution of the Problem 104-3   

Item a

Initially we will calculate the line current knowing that P = V_g I_L. Thus, we get:

And the field current is given by eq. 104-09. Soon

Therefore, the armature current given by eq. 104-21 is:

Item b

The armature voltage is given by eq. 104-02.

Doing the math, we find:

Item c

The losses in the armature winding are:

Doing the math, we find: