Question

Vt= Ea– Ia(Ra+ Rse) is the equation for _______________

(a) Short shunt compound motoring mode

(b) Short shunt compound generating mode

(c) long shunt compound motoring mode

(d) Cannot be determined

I had been asked this question in an online quiz.

I want to ask this question from Methods of Excitation in section Commutation Process & Excitation Methods of DC Machines

Answer 1

Right option is (b) Short shunt compound generating mode

The explanation is: In a DC machine, for a long shunt compound motor Rse is connected in series with armature, while in short shunt compound motors Rse is connected in series with terminal voltage. IL is supplied to the terminals which is equal to Ia – If.