Yeah, it is to keep output voltage constant independent of load variations. Actually, I had earlier simulated a half bridge 1-phase voltage source inverter using a direct closed loop control of instantaneous output voltage. It wasn't controlling too well for very different load values and/or reference voltage values.. So using a feed forward control should improve that, is it?
What if the control loop is reacting on instantaneous voltage instead of rms.. assuming balanced loads and that the output frequency remains constant?