First thing is that the model you attached is developed in MATLAB 2017a, and I have matlab 2016b. So I am unable to open it. If you can export it to a previous version by: File> Export Model To> Previous version .
Now coming to your problem. I think you modeled the PV using the single diode model equations. Now to use this model with the other electrical components, you need to convert it by using a controlled current source block in MATLAB Library. The output current from the mathematical model is fed to the controlled current source and then you can connect a series resistor or a shunt resistor or a DC link capacitor across the terminals of controlled current source block. To make the terminals you can use connection ports.