Question

During the starting of the 3-phase synchronous motor by damper bars, the field winding is usually short circuited so that starting torque is equal to __________

(a) induction motor torque plus an additional torque produced by short circuited field winding

(b) induction motor torque

(c) electromagnetic torque

(d) reluctance torque due to rotor saliency

I have been asked this question in homework.

This question is from Physical Concepts of Synchronous Machine Operation topic in section Synchronous Machines of Electrical Machines

Answer 1

The correct option is (a) induction motor torque plus an additional torque produced by short circuited field winding

For explanation I would say: Using dampers to start the synchronous motor, it will produce induction motor torque initially along with the torque due to shorted field winding.