@Maryam, the answer to your question is no, OpenStudio cannot currently use Radiance to (spatially) simulate electric lighting. Sorry! It is a bit confusing since there is that luminaire object there, but as David intimated these luminaires are not exported to Radiance. They also do not currently support photometry -- only position and load.

To be clear, the Radiance routines in OpenStudio do modify the electric lighting load schedules, but they work simplistically off of the "Daylighting Control Point" illuminance, linearly interpolating the lighting power fraction based on the (Radiance-calculated) daylight illuminance versus the control point's setpoint. What OpenStudio-Radiance does not do is perform a spatial simulation of the electric lighting using photometric data (e.g. "IES Files").

This is a common misconception. The way EnergyPlus works is that you input a Lights object (documentation), and specify which zone it serves, its lighting power and fractional schedule, and how the heat is distributed.

EnergyPlus doesn't care whether your Lightsobjects are enough to provide enough lighting to your zone.

If you put a daylighting control in the zone, EnergyPlus just assume that whatever lighting power your specified will provide the illumance setpoint you have specified when your fractional schedule is 1 and its nighttime.

In your case, whether you have a LED or a fluorescent fixture, you'll just have less Watts for the lights object, and you could tweak the fraction radiant and fraction visible.

We did make a Luminaire object when we first created OpenStudio that works just like a Lights object, except it does have a position in space and an orientation/rotation. Another difference is that it can only be (W) vs. (W/person) or (W/area). The intent was at some point in the future this could be used for Radiance simulation of electric lighting (vs. daylighting) but that isn't on our short term plan.