Need some assistance regarding fluctuation of MPPT DC Analysis

Simbaa Registered Users, Users Awaiting Email Confirmation Posts: 2

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


  • BB.
    BB. Super Moderators, Administrators Posts: 33,522 admin
    Any "variable" shading on panels--Power lines, trees (blowing in wind), birds roosting on a location, etc.?

    You could also have an overheating or even arcing connection in your solar array wiring... Note that arcing/overheating connections are a major source of solar array/wiring fires.

    You could also have an intermittent connection in one (or more) solar panels. Look for "browning"/"blackening"/"odd looking cell(s)) in your panels.

    You could also "swap" the MPPT1 and MPPT2 arrays and see if the problem "follows the array" or "follows" the MPPTx input... If the problem "follows" the MPPTx input -- Then you may have a "bad" GT inverter (intermittent internal components/heat sensitivity).

    Those are my first guesses. Doing the "MPPTx" swaps is probably the easiest test and do that first.

    Looking for wiring/array "abnormalities" as best you can (up close inspection, using binoculars, etc.) before physically checking every wiring connection (bad MC4 connectors/crimping failures are common issues).

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Simbaa
    Simbaa Registered Users, Users Awaiting Email Confirmation Posts: 2
     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.