Decentralized control for series cascaded PV inverters - PSIM Simulation

Hi. I'm doing my thesis project for simulating a series cascaded pv inverter. In the first part, I am supposed to implement a decentralized control which will be used afterwards as a control/comparison for the proposed improvement. I am simulating this on PSIM. In the photo below is the block diagram I'm trying to follow. I was able to implement the voltage and current loops. I'm having troubles with implementing the power calculations loop. Is anyone familiar with the control blocks implementation in PSIM? I have also attached one of my reference research paper.