Need some assistance regarding fluctuation of MPPT DC Analysis

[Simbaa]

I was checking the DC analysis on app and found like DC from MPPT1 is fluctuating as compared to MPPT2
What can be the possible reason behind it and how it can be addressed?
Its a 9.65kw grid tied based system. The inverter I am using is Solis 3P-10K 4G along with 22 Longi 440W PVs

 

[bladerunnerpv]

What's the orientation of the solar panels connected to mppt1 and mppt2 ? How many panels on each?

 

[Simbaa]

What's the orientation of the solar panels connected to mppt1 and mppt2 ? How many panels on each?

All of solar panels are south facing. There are total of 22 panels, where both mppt1 and mppt2 gets 11 panels each.

 

[binky]

So are both sets of panels clean and free from bird poo? Any batteries connected, or export limitation?

It does look a bit like a failing mc4 , how long has this been going on?

 

[Simbaa]

So are both sets of panels clean and free from bird poo? Any batteries connected, or export limitation?

It does look a bit like a failing mc4 , how long has this been going on?

Yes both sets of panels are washed once a week and even then this fluctuation does comes. Also there is no batteries connected as its ongrid based system and no limitation on export as well. The system is up and running from 3 years but I never checked this report earlier. I just was scrolling on the app and that showed me this fluctuation.

 

[Simbaa]

I was checking the data and when I compared the IGBT temperature, I have attached the report of one day from March and other day from June
I can see the mppt1 and mppt2 strings working almost fine during winter but in summers there is fluctuation coming in them.

 

[binky]

At 70C inverters start to shut themselves down to prevent overheating and damage to internal components. They do this by making themselves less efficient, ie altering the MPPTs, so given the current weather, it is possible that your inverter is altering MPPT2 to achieve this. Simple thing you could do is swop the strings between the MPPTs to prove it's the inverter rather than a string fault. You could also try improving air movement past the inverter with a desk fan and see if keeping it cooler makes any difference

 

[newfutile]

isolate ac and dc before pulling mc4’s