Hello,
There is not a block that will calculate P and Q for you automatically, you will need to apply this logic yourself. But we have several demo models that show how this can be done, for example the "Microgrid in Island Operation", "STATCOM Cascaded H-Bridge Converter", and "Neutral-Point Clamped Converter" models. I also attached a screenshot from the NPC demo model where the P and Q equations are implemented using the measured three-phase voltage and current waveforms. Let me know if you have further questions on this topic.
Regards,
Kris