Question

Which among the following makes double layer windings advantageous than the single layer windings?

(a) ease in the manufacture of coils and lower cost of winding

(b) less number of coils are required as spare in the case of winding repairs

(c) fractional slot windings can be employed

(d) ease in the manufacture of coils and lower cost of winding, fractional slot windings can be employed, less number of coils are required as spare in the case of winding repairs

I have been asked this question in final exam.

The above asked question is from Armature Design topic in chapter Design of Synchronous Machines of Design of Electrical Machines

Answer 1

Correct answer is (d) ease in the manufacture of coils and lower cost of winding, fractional slot windings can be employed, less number of coils are required as spare in the case of winding repairs

The explanation is: The double layer windings have an advantage over single layer windings because of ease in the manufacture of coils and lower cost of winding, less number of coils are required as spare in the case of winding repairs, fractional slot windings can be employed.