Question

4.4 Th e armature of a motor has a radius of 0.12 m and an effective length of 0.25 m. The armature winding consists of 37 coils each with six turns accommodated in 37 slots. The field structure has four poles which cover 70% of the armature periphery. The average flux density in the air gap un- der each pole shoe is 0.8 T. The armature winding is connected in two par- allel paths. (a) Determine the constant k for this machine. (b) Determine the generated voltage when the armature is rotated at a speed of 20 r/s. (c) Determine the torque produced when the armature current is 40 A. (Section 4.3) ture voltage o

electric machines and drives

Answer 1

4. 4) The given matechine is a Motor and the armateize uwencng is commeitd in too Parallel paths e machina hat amn ature trending contains 3チcells So て Number of slots (ar) ,'··ZF number of cbehe Number of selots-->Tris a dauble lasex turndeing machine lumber of poles IP (guen) Average flu densil in the ais gep tinder each pole shoe Raclurs of armture b.m Effective langth (a) - 0.2 sm, o le shoe egenuYd bwhere k is the canstuttur per pole sec Z-Total neumber of conduectoos. てP att舟 Nlumber of poles -> Altern 4-千千 cmductors e when spee

Here ф →is flux per pole Average tur denity - Total fluus Total area of core(-fluy ati rt 0-2 乙 0 25 ro z 0 .03968× t+4 x 40 669 , ( 968 110に Ea 661. 1468 vol detemnine the torque e Produce ed again amature (c) て ㄧ乙 213.12003936 N-m