Synchronous Motor Load

Yes, yes... More clarity and detail in the question will get more clarity and detail in the answer...

Homework?

Answer is given by RC (correct) now explain why

Hi

For operating syn motor as a syn condenser, the necessary condition is to make the motor over excited under no load. At this condition s only we can expect the motor to operate as a capacitor, delivering reactive power for the system, the amount of reactive power supplied depends on the amount of excitation given to the motor. We can obtain both leading and lagging reactive power.

So the syn motor must be with no load for making it syn condenser.

A good paper (perhaps too advanced?), the pdf shown first on the google search result page.

Here

Yes, motor will draw active power from the line to supply its own electrical and mechanical losses. If the excitation is taken from the exciter mounted from the same shaft, then excitation power will also be taken from the line. This is irrespective of load condition of the motor (at a load or no load).

As Qqberci said, it can be done but only to the limits of saturation of the rotor iron. So as your load increases, more and more of that capacity gets consumed in exciting the rotor field for the load, leaving less head room for over excitation as a synchronous condenser.

I have seen this done in two facilities (foundries) with the need for large air compressors because the peak loading on an air compressor can be predictably determined and the extra capacity can be built-in to allow them to function as synchronous condensers for the rest of the plant.