HI All, below is the graph of solar power plant 6kw@48 V, on clear sky there is drop multiple times , is it due to the fact that another power source is connected in parallel , to the same bus bar rectifier which takes 220V AC and convert it into DC 48V. what should i do to make this graph as per standards
If you have 2 charge sources and they are both independently controlled then you can make your solar controller absorption and float settings something like 0.2V higher than the other charge source so solar takes priority if it is available.
For an informed response, you really need to detail your system and how it is configured. Various factors could contribute to that curve.
there is a rectifier having capacity of 18 Kw , Load is around 5 KW , solar capacity is 6.16KW , batteries installed are 9009AH @48 V lithium , Diesel generator installed here is 30 Kva. the site run in bad grid area means Commercial power is available for 12 hours , means available for one hours and then off for 1 hours. this is the pattern.
load , batteries ,rectifier and solar through charge controller is connected on rectifier bus bar.solar voltage is set 0.5 volts higher then rectifier output .54v and 54.5 volts respectivly.
If the battery state of charge is enough below 100%, then the target voltage is by far higher than the momentary charging voltage, so that 0.5V difference doesn't matter.
For example, charging active, target voltage 56V (3.5x16) and the actual voltage of the battery is now 53V (3.3x16). A 3V difference so 0.5V set is irrelevant in this stage of charging.
But the Kirchhoff's laws are relevant and apply and the charging current will be a sum of how much each charger (solar and rectifier) can supply. In other words, each charger's internal resistance.
As the grid charger is way more "capable" than the solar charger (3:1), will influence a lot the current supplied by the solar charger.
the question is about load sharing, if increase the voltage difference between the two charging sources to 2V that is 56 and 54 volts then the solar takes more load.
for example with previous settings load is 60 Amps, 40 amps were coming from recifier and 20 A were coming from solar , when i changed the charging settings and increase the voltage difference between the sources to 2volts solar took 40 Amps and rectifier took 20 A. there was impact accordingly on the yield.
That's correct. The closer is a charger to the target voltage, the lower will be the current it's supplying. You can even stop a charger setting its target voltage equal or a tad smaller than the actual voltage. Physics 101....
dear how can I further lower charger current and increasing solar current further , without effecting batteries health
The lower the charging current, the happy the batteries will be in the long run.
So lowering one of the charger's current, will not affect battery health, as long as the battery reach the float stage.
Lower the rectifier target voltage up until you are satisfied with the current it supplies.
Or make some automation that will tune these voltages based on the battery's SOC, available solar, etc.
