question

Hi Daniël!

Thank you for your answer! There are several reason why your answer is somehow confusing and astonishing for me.

First I am not sure if my English is good enough to understand

"ESS does not know that the inverter doesn't have enough capacity to feed all the loads"

therefore to point it out and to understand in detail my question A) and B)

A) Do I understand your answer correctly like this, that ESS controls for each phase individually and separately the flow of energy which can be handled individually by each of the specific inverters? Correct?

B) Today there is no calculation from the ESS system to balance all three phases common? Correct? But perhaps there might be a solution in future for this?

How do I have to change my setup to handle a load with 3600W ?- Here some more questions

C) For my example would it helpfully and work when I would have a Multiplus-II 5000 which is able to do 4000 W power? So the 5000 inverter could do the required 3600 W power in my example? (Of course it has to fit what the batteries are able to deliver, please assume the batteries can do any power which is being needed)

D) But when there would be a big load with 5500 W on single phase L3 it is again with the bigger Multiplus-II 5000 the same problem as in A) / B), that the ess system than buys from grid 1500W and the other two inverters will still stay in standby? Correct?

E) What happens when there are two Multiplus-II 3000 parallel for each phase? Would it be than possible to handle a AC-Load up to 4800W completely from the batteries?

Sorry for asking so much, but for me it is important to understand in detail. I am planing for several customers charging stations for EV cars. Energy should be collected during the day in batteries and at the evening when the car returns empty it should be loaded only from the batteries and not from the grid.

DayAndNight

Hi Daniel,

people who make a big battery at home and have pv also like to buy an electric vehicle. Your system comes from boats but the future is a pv a battery an an ev. Unfortunately the ev‘s mainly have one phase chargers. So, it would be recommended that you put this simple advancement to you update list for ess, if Victron wants to satisfy the customer demands.

There are no symmetrical loads in real life, even when I cook. Another problem of your used algorithm is that the inverters are very inefficient at 100% of load (88%). So if all inverters work at 33% it is more efficient than one inverter works at 100%. Your algorithm has no single advantage in ESS systems. It is good for boats or camping issues or island mode.

for my issue, I buyed an expensive transformer (hinausgeschmissenes Geld) to make out of 400V (2 phases) —> 230v only to drive my car with the sun, when I come home late from work using recycled lion cells.

But now I can only use two of three inverters ...

Hello Daniël,

I can only confirm the experience of my previous speakers. I sold a three-phase MP-II 5000 system to a costumer of mine, with the intention to have enough power to load his car and keep his household on green energy. Unfortunately he drives a Hyundai with 1-phase 7.4 kW loader, and in the moment he is taking nearly half of the energy from grid when he needs to load his car fast. I agree with you, that 3-phase supply would be a solution and a better way of charging, but as mentioned by DayAndNight, a lot of EVs are connected by 1-phase with up to 7.4 kW.

As mentioned from others, this behavior is not what I suspected the phase compensation to be. So please consider a "Symmetrical ESS" as a practical solution for installation, your competitors on the on-grid market in D-A-CH do so too (all one-device 3-phase systems: Fronius Symo Gen24, Kostal Plenticore, ... but the SMA Sunny Island System in 3-phase setup too). I know your system is designed for off-grid solutions, but I think the on-grid market is a big fish too. And I would like to sell more Victron Multiplus solutions..

Best regards

Christian Dorst

Dear Daniel,

as you can see, within a short period of time already 5 very disappointed customers claiming the same problem with phase compensation in three phase systems. You can be sure, that the biggest market for your future is on-grid in combination with EV charging. So, my question, could you look at this thread again and discuss this with your team members? I am sure that people who get aware of this problem, will not decide any more for Victron. Your future customers will not make big investments in three phase systems that are not usable for the target group.

Can you provide a solution within a short period of time? Can you tell me the name of the file, where i can find the code, for updating it just for the community members? As described already by "Ossi" the new algorithm for on-grid three phase systems in ESS is much simpler than your old approach like:

What we expect for phase compensation is a symmetrical ESS feed:

Grid counter L1+L2+L3 = Pgrid

VEBusPower DeviceL1 Power= -0,333*Pgrid

VEBusPower DeviceL2 Power= -0,333*Pgrid

VEBusPower DeviceL3 Power= -0,333*Pgrid

----------------------------------------------

Here is the last community member who claims the problem:

Hi Daniel,

there you see: every day the next econmic loss and unsatisfied customers:

N-DEE gnagflow · vor 6 Stunden

I have the same problem, with a 3 phase system, But a different view on the Problem. Load on L1 2,4kw L2,L3 nearly 0 (Grid 0W). So one Multiplus II runs at 2,4kw what is not very efficiency only 88,5%. If every Multiplus is Running on 800W (Grid 0W ) the efficiency is 95% based on Victrons efficiency curve. And that is saving a lot of Energy for me. Have a sunny summer.

Hello @Ossi,

thank you for your detailed explanation, which looks for me of a profound and deeply understanding of the situation. Great! Thanks!

I agree to your description and your implication.

I am somehow disappointed, because when started with Victron I read a lot of Victrons documentation as ESS Design & installation manual and there can be still read at 7.2 Three phase ESS: "ESS balances the total power (L1 + L2 + L3) to 0 W." and there is for my understanding no information that is might be ... or it can happen that ..... or be aware that ... and in my above example L1 (1 W) + 5 W (L2) + 1241 W (L3) with a total of 1200 W is far away from 0 W

I understand now, based on my real experience and discussions here the technical background but I had different expectations when I read "ESS balances the total power (L1 + L2 + L3) to 0 W." and I cross checked again the documentation, I could only find a note for maximum charge current not any other written restriction, I had now to discover.

I don't want to complain here. I have a work around for my 3,5 kW EV charging problem. I simply reduce and control the power for charging the EV car when no PV support is available to the load the single inverter is able to drive. So it takes longer to charge the car which is no problem for me if the car is fully charged at 10 PM or 1 AM in the night. The work arround is only simply to realize based on the wide possibilities and functionalities Victrons system is offering so it is still great for me!

You created already the name what I need and I think Victrons world is waiting for:

"Symmetrical ESS"

I am sure Victron has the potential to offer a solution for Symmetrical ESS, hopefully threads and disscussion like this one creates the priority at Victrons headquarter that we will have it very soon available.

DayAndNight

Exactly what you say is what we expect as phase compensation, an external control does somehow adds an additional system that can fail which would be nice to avoid, but also requires a Development.

The more people raise the issue the bigger the chance that Victron adds the feature of real phase compensation to supply high unsymmetrical loads of electric vehicles.