Question

A 8-pole DC machine has an armature of radius 0.4m and effective axial length 0.3m. The armature winding has 60 coils of 5 turns each and is simplex wave-wound with parallel path 2. The average flux density at the air-gap under each pole is 0.7T. Find the following: 0 The total number of conductors in the armature winding (11) Flux per pole Wb/m2 (iii) The machine constant ke or kt (iv) Induced armature voltage if the speed of the armature is 400 rpm V

Answer 1

1= 0.4m 0.3 m No of pols P=8 radius of armature axial length of No. of coils= 60 No.of Turs = 5 Simplex wave winding i Total i A=2(no. of parallel baths) no. of Armature Conductors :(z) 2x No. coils No, of Turis ber coil 2 x 60 x 5 - 600 (11) Actual pole area : Ap 27sL P 27 x 0.4 x 0.3 2 - 0.3769 m 2 Efective Flux density B- Flex ber bole 3. Ap = 0.7 x 0.3769 = 0.2638 Wb 0.7T (or Wb/m² Machine constant ke ZP 0.159* ZP - 0-159 x620x2 27 A A 95.4 con V-S Vad/web (iv) Induced EMF OZNP 0.2368 x 600 x 400 x 2 60 A 60X2 947-2 V