DC Synchronous Machine

Please explain what you mean by "DC synchronous machine".

For me, synchronous implies rotating frequency exactly matching the supply frequency, but for DC there is no frequency to match.

Reactance X is a function of the frequency. XL = 2*pi*f*L and XC= 2*pi*f*C. In DC, the frequency is zero. Voila, no reactance.

Really, as lynlynch says in another post,

i must get a life.......................

The reactance is the opposition to the flow of alternating current caused by the inductance and capacitance in a circuit rather than by resistance. DC is not applicable on this approach.

I would venture to guess that he is referring to a synchronous machine with maybe an externally excited DC field control using a brush type slip-ring connection.

What is the role of reactance in that scenario? We still need to know the context of the question. Reactance as it affects the rotor field or reactance in the stator?

My goodness! this will teach me not to jump to conclusions ! Thanks for being my conscience

The OP's orginal question demonstrates almost a complete lack of knowledge on the subject and little pertinent data, so no wonder people went off in the wrong direction.

A properly made question containing ALL relevant information will always allow better answers.

Its a bit like the old Computer saying:-

G.I.G.O.

Have a great day Guys......