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nurbi avatar image
nurbi asked

Additional MultiPlus for low power generator and/or wind turbine

Hi community,

I'm having 3 x MultiPlus II in 3-Ph grid paralleled configuration, 48V battery, ESS, 14kWp PV power. All runs fine. I would like to add a low power (500W - 1000W) AC souce to feed into the 48V rail. Idea is to use a small 230V/1000W generator or to use a micro-wind turbine with AC inverter (https://www.myskywind.world/) to have an additional energy source. I could use an MPII 1600W version, which offers a VE.Bus connection. I have the DVCC option set to YES in my Cerbo, hoping it took over the control of everything I connect. What happens, if I connect another MP with an erratic, low-power 230V source? Have anybody tried this out before? Could I damge anything else than the 1600W MPII? Thank you for your ideas and thoughts, best, Nurbi

Multiplus-IIGeneratorHydro and Wind Power
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Alexandra avatar image
Alexandra answered ·

@nurbi

A GX is only designed to control one VE bus system. The GX is already handling the 3 phase system.

Connecting the other inverter is not an option except for monitoring. There will be no control.

Confirm again the additional MP inverter you proposed. As far as I know there is not MP2 1600 in 48v. Maybe it is a phoenix smart or the older MP?

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Michelle Konzack avatar image
Michelle Konzack answered ·

1) Generator

If you want to use a generator, use a Charger but be aware, that you should reduce the load on the genetator by 33%.


Hence if you have a 48V/20A charger (~1000W) you will probably have around 1100W or 1500VA on the AC side, which mean, you need a Generator which has a continious power of 1500W minimum. Most of the Generators are labled by their peak power, hence 2000W/2500VA.


Note: I have killed a Nutool AG2500 by loading it with a LEAB ABC2450 (~1400W) which resulted in a GenSet load of 1600W/1900VA and overloaded the China crap.

2) Windturbine

Why not charge the Batteries directly from the Windtturbine, which is much easier. If this small Windturbine is AC coupled, your MultiPlus-II will have a hard time.


Only bigger Windmills (3,5kW and up) have a real GTI (230V or 400V) and run stable AC coupled.


Aside my AC coupled Fronius Primo 8.2-1 I am fencing a 7-12m high 3,5kW windmill, which should deliver in my location with 7m hight around 16MWh a year... but this would then require a 3rd MultiPlus-II 24/5000 parallel!

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nurbi avatar image nurbi commented ·
The generator in my case is a given piece of equippment I don't want to change. It has a 1kW inverter output and can't be overloaded. I would just use it in case of a total grid-loss. My idea was to use a 4th MP to have an extra generator input.


The wind turbine could constantly help to harvest energy. I've seen very affordable 48V China models with a battery charger. The question here is: Could I connect these to the 48V rail in parallel to my expensive Victron stuff? I guess the GX would wonder what is going on if an alien device pulls-up the charging voltage. Or has anybody made experience in mixing Victron chargers and MPPTs with other 48V equippment? I would give it a try and would even risk to blow up the China stuff but I don't want to harm the blue ones...


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Michelle Konzack avatar image Michelle Konzack nurbi commented ·
You need a SmartShunt setup as EnergyMeter for the Windmill
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nurbi avatar image
nurbi answered ·

Sorry, I'm talking about MultiPlus 1600VA (https://www.victronenergy.com/upload/documents/Manual-MultiPlus-1600VA-EN-NL-FR-DE-ES-IT.pdf), not MP2. If it is not controlled by the GX, could I somehow tell it to work as charger only (It's way cheaper than the Skylla)? What would happen, if I try to run a charger on the DC-Bus, that is not controlled by the GX? I could connect a generator/wind-turbine to it and program the same charging curve. Would it interfere with the other setup? Could I give it a try or do I risk to blow up the expensive MP2 and MPPTs? Thank you, best, Nurbi

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Michelle Konzack avatar image
Michelle Konzack answered ·

Yes, you can use the MultiPlus 48/1600 in "Charger only" mode, but also here, you need a SmartShunt setup as EnergyMeter that the CerboGX is aware of the external charging source

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from-waste-to-wind avatar image
from-waste-to-wind answered ·

I'm looking to do the same. Do you have a managed battery? In that case, the Multiplus can feed the excess energy from the windturbine to the grid. (I think the smartshunt alone is not enough, as long as the Multiplus doesn't load the windturbine and the batteries are charged) the voltage will increase but no current can flow. So I think you need SVS - through a BMV?)

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