3 Phase 4 Leg Inverter

¿¿Put √3 into the simulation in appropriate places??

It sounds as if you have defined your simulation in the voltage domain only.

You must define it in the time domain for the proper relationship of phase voltage to line voltage. The Sqrt(3) does yield the relationship as the ratio between the two if all loads are equal. Otherwise, it requires the time domain to describe it correctly.

You should be able to do this after your 2nd year of study in EE.

You should be able to do this after your 2nd year of study in EE.

Or some trial and error with your simulation package, but that will only give you the answer not the understanding behind how to get the answer.