PV array current unstable for one array and stable for the other array

Hi, I need help with the following part of my model, containing 2 PV arrays (PV3 and PV4) and a battery.

Why does the PV current signal for PV3 (Ipv3) present strong fluctuations while the same signal for PV4 (Ipv4) remains stable ? What can I do to make both signals stable ? I need this to ensure stable produced PV power for both arrays.

I don't know if the slx file is needed. If so please let me know and I'll share it.

Any insight would be highly appreciated. Thank you!

[Isha]

Hello,

This behavior is likely due to control tuning differences. PV current typically oscillates when the MPPT or PI controller is too aggressive or interacting with the battery control.

To troubleshoot this issue you can check the following:

• PV3 and PV4 use identical MPPT settings (step size, sample time)
• Reduce MPPT step size to minimize oscillations MPPT Algorithm - MATLAB & Simulink
• Retune PI gains (lower Kp/Ki if needed)
• Ensure proper control hierarchy (fast current loop, slower MPPT)
• Add a small low-pass filter to the current signal

You can refer to this MathWorks example to compare tuning and expected behavior: Solar PV System with MPPT Using Boost Converter - MATLAB & Simulink

Hope this helps.

[Yosra]

Thank you very much !

It was actually a combination of sample time mismatch and parameter tuning issue. The model is working now.

The referred link was also very helpful.