question

buurte avatar image
buurte asked

9 multiplus_2 in 3 fase parralel. 3 charging and 6 discharging

With the company we are building a large 3 fase battery pack.

now the question is can we use 3 multiplus_2 for charging and 6 for the discharging, all connected with the same VEBus?

Multiplus-IImultiplus ve.busmultiplus in parallel
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3 Answers
Phil Gavin avatar image
Phil Gavin answered ·

DC charging directly to the battery will work as normal, and each phase's inverters will in unison draw what they need on a per-phase basis. But that isn't using the charging capability on the inverter.

So I assume you are talking about AC charging.

The nett effect will be the shared response of all inverter/chargers in that phase.

In other words, if AC charging is 100A on phase 1, and discharging by a load is 90A on that phase the net effect will be 10A charging spread equally across all inverters on phase 1. (There will be some margin of error).

What you will not be able to do is have inverters respond differently if they are parallel on the same phase.

So, given the scenario I described for phase 1. If you loaded phase 2 and phase 3 so that the load exceeded in AC charging on those phases respectively, discharging could be achieved on 6 inverters and charging on the three phase 1 inverters. Ideally, the three phases should balanced regarding the loads and charging facilities.




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Alexandra avatar image
Alexandra answered ·

@Buurte

I have a few questions. Are the three being used to discharge are they going to be part of the three phase parrallel set up to contribute to loads? If not, then they are not part of the VE bus system

If they are then you can have switched as a group off but you will not be able to run ESS assistant.

Then if the three being used for grid charging are not connected via ve bus then yes you can. The batteries would discharge to loads through the other (main) system.

You would need a has DC system on the GX enabled as well. Are they CAN managed batteries?

Eventually the battery bank will be fully depleted if the loads are always continuously higher than you are are able to charge at with the three grid connected ones.

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buurte avatar image buurte commented ·

see my answer please

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buurte avatar image
buurte answered ·


@Alexandra , @Phil Gavin

The 3 for charging are only for the charging. The will not contribute to the loads .The 6 for discharging are used in a 3 fase parallel system. We will use the multiplus2 15kva. So the output will be 90kva total.

The batteries are CAN bus monitored. There will be 10x 16.7Kwh batteries in this battery pack, so a total of 167Kwh

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