question

jayesh avatar image

3 Phase Grid Tied Battery storage system with Generator Back Up - Please Help

Hi there,


I am quite new to Victron but have been using SMA Sunny Island. I have heard great things about Victron. I have the below scenario.

The panels will be connected to a 3-phase grid-tied solar -PV inverter to the main-distribution board at the house. To this distribution board we will connect BYD LV batteries using a 3 Phase battery inverter. This inverter will operate in self-consumption mode when grid is available.

When the grid goes off the line, the system will back up all 3 phases till the batteries reach their maximum allowed discharge level.

The system will then start a suitable generator automatically (to be provided by you) and will charge the batteries to a pre-set charge level before turning it off. This cycle will continue till the next day, when the Solar panels starts producing power or until the grid comes back on.


Do i use the Multi-plus 2 or the Quattro to achieve the above solution ?


Many thanks

Jay

battery chargingGeneratorgrid3 phase
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1 Answer
Paul B avatar image
Paul B answered ·

Hi there you should use the Quattro units you would require 3 units for 3 phase. this will then give you auto change over from grid to generator and a priority to grid if both are avaliable.


for ease of use I would akso suggest a Colour Control or a venus GX so that remote site access can be acived.

You dont mention sizing so I have not any coments in that area

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Hi Paul,

Thanks for the quick reply. I was planning on the below components.


12.6 kWp of panels

15 kW 3 phase SMA Sunny Tripower Inverter

27.6 kWh BYD Batteries.


I was looking at the 5kVA models of the multiplus 2 and the Quattro's and was looking at having 1 on each phase.


The system needs to behave like an ESS.

Ideally Solar panels should supply the loads first. The batteries should have second priority, with the grid coming in to meet any need, if the Solar/batteries can't meet the demand.


In case of a grid failure, I would like the Solar Panels to work by meeting the need and also by charging the batteries.If there is not enough sunshine and if the batteries are drained to their minimum discharge level, then the generator steps in and charges them back up to a preset level of charge. This cycle should keep repeating till the grid is back online or the Solar Panels start's producing power to charge the batteries. The generator then gets shutdown automatically.

Can this be achieved?


Cheers,

Jay


Yes and no.

Yes, it will work as you thought it would. You can even have only 1 Victron for one of the phases and move your critical loads to that phase (if possible).

BUT - (and it might just be my crappy generator, although it has AVR), if your setup triggers the generator, even though you might still produce power, my quattro does not sync the generator phase with the on-grid inverter (i have a Fronius) so until generator is powered off, all my solar goes to waste... again it might just be a bad genny on my side.


To avoid this if you use a color control, you can use the generator auto-start function and set "quiet hours", where these hours might start after 9 or 10 AM when the sun is up and you should be producing over 2-3 kwh on your system