Page 770 - Basic Electrical Engineering

No. of slots per pole per phase,

1° mechanical electrical. We have to convert all mechanical degrees into

electrical degrees.

Since, P = 4,

1° mech = 2° electrical
10° mech = 20° electrical

α = 20°, m = 3

For calculation of pitch factor,

No. of slots per pole

This means the coil sides of a full-pitch coil will be at a distance of nine slots.
Then the coil sides will lie under opposite poles occupying similar locations

under each pole. Since the pole pitch is eight, the slot pitching has been done
for one slot angle, i.e., by 20° electrical.

Thus, β = 20°

Example 10.3 The induced EMF in a synchronous machine is 11,000 V

with a distributed fractional pitch winding. If a concentrated full-pitch