question

maha avatar image
maha asked

Load voltage too high

I use a ESS-System with a Fronius on AC-in and a MPPT 250/100 on AC-out and DVCC is enabled.

Absorption voltage in the MultiGrids is set to 57.6V and in the MPPT too.

In this constellation the load voltage will rise until 58V. Therefore I set absorption voltage to 57.2V in the MultiGrids and then the max. voltage is 57.7V. It seems that the MPPT will oversteer the voltage of the MultiGrids with 0.4V. I thought that the MultiGrid will be the master...


In DVCCMenue SVS is disabled.


When SVS is enabled it's the same - voltage too high!


Is that a bug?

ESSmppt charging
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2 Answers
maha avatar image
maha answered ·

Batteries are 4x 170Ah Hoppecke OPzV (Gel).

I don't measure with a Multimeter. I think that the MPPT oversteers the MultiGrids and that shouldn't be in a ESS-System...



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Daniël Boekel (Victron Energy Staff) avatar image
Daniël Boekel (Victron Energy Staff) answered ·

Hi @MaHa

When 'feed-in excess solarcharger power' is selected, the MPPT charge voltage is set 0,4V higher so the multi can 'pull down' to the actual charge voltage and send the rest to the grid.

so yes, multi is still master here.

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maha avatar image maha commented ·

Thank you for your information.

I had already thought so and therefore also reduced the value in the MultiGrids.


Here you can see what happens when sunshine comes and goes and the MultiGrids are using 57.6V absorption.

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