I want to plot an efficiency vs load resistance curve of a boost converter connected to a PV array supplying a respective voltage across the load.

I took a PV array and connected it to the boost converter keeping the irradiation level at 1200 W/m2. According to my calculations, Rload = 6 ohm and Rmp = 4.22 ohm.

At this configuration, my converter is giving the desired output and my MPPT controller is tracking the maximum power very smoothly. But, when I increase the load resistance keeping everything else unchanged, my MPPT controller gives power tracking value greater than the maximum power available at that particular irradiation level. Why is this happening and how to solve it?

I want my controller to track the right power irrespective of any load resistance changes and the right output voltage according to the generated duty cycle.

Please help me out. Thank You