Main Dimensions of a DC Machine…

I thought why not try the program (see post below) on the question that was asked in the Anna University exams recently. (Last Month)

EE 1403-Design of Electrical Apparatus [R 3348-some stupid AU code for the question paper]

Problem 12(b)

A 5kW, 250 V, 4 pole, 1500 rpm dc shunt generator is designed to have a square pole face. The average magnetic flux density in the air gap is 0.42 Wb/m^2 and ampere conductors per meter = 15,000. Compute the main dimensions of the machine. Assume full load efficiency = 87 percent. The ratio of pole arc to pole pitch = 0.66. (16)

I ran the program for this given data and present the output here:

12(b)

now don’t you think I should be awarded full marks for this probelm anyway ? 😉 . Oh and this is the question of which I ttended both the choices. That’s because I forgot that for a ‘Square pole face’, you are supposed to assume L/(psi*tau)=1. I remembered this once I was done with the other part and finished the problem anyway.

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