Problem 102-4    Source:  Problem prepared by the website author.

A DC machine has wavy armature winding, 6 poles, with 20 conductors per slot. Assuming that the machine has 48 slots and the induced voltage in the armature is 640 V at 600 rpm, find:

a) the number of active conductors;

b) the magnetic flux in that machine per pole.

Solution fo the Problem 102-4   

Item a   

The number of active conductors in this machine is given by the product of the number of grooves and the number of conductors per groove. Then:

Item b   

To calculate the magnetic flux, we must calculate the number of paths of the wave winding and we know that it is given by eq. 102-10, shown below.

As m = 1, since the machine is simplex, then:

We are now in a position to calculate the constant K_a using eq. 102-14, shown below.

Then, replacing the variables by their respective values, we find

Now, using the eq. 102-13 and working algebraically, we get