Power input fluctuating causes?

I am running my model however my power input is fluctuating and I am trying to find out why. The input consists of PV panel and Battery. The power generated should be a constant value since the irradiance is set as a constant. The model is attached below, thank you.

Answer 1

[Dr. Pemendra Kumar Pardhi]

Power extraction from PV is dependent on controller.

Actualy your inverter controller is responible to trac the MPPT, because of this power is fluctuate.

either you have set constant irradiation as well as temperature.

[EngTat Chung]

May I know how do I keep my power constant?

[Umer Sohail]

In order to extract, maximum (constant) power from PV you need to regulate the Vdc (which is same as Vpv in your model) to Vmpp.

[EngTat Chung]

May I know how do I convert it to Vmpp?