ESS Image

ESS

Hulp met node red.

Ik ben bezig met node red maar ik vrees dat ik er gewoonweg te weinig van snap.

Voor dat ik heel veel verkeerd doet is mijn vraag, is er iemand in de positie en de mogelijkheid om mij even te helpen met een aantal instellingen.

Ik wil een instelling maken dat mijn grid feed in veranderd door de soc van de batterij.

En ik wil dat er een relai schakeld op de cerbo bij een soc van >95%

En ik wil een relai schakeling maken op basis van temperatuur.


Ik hoor het graag :)

richard-veghel asked
Dirk-Jan Faber commented ·

3 Answers

How to control Battery charge current with ESS + DC coupled feed in

Hello community, i have a very interesting Question from my side because no one can answer me this. Also not my Victron parts seller.

  • Standard ESS System with 3 or 6 Multiplus. 48-54V System!
  • A Few Victron MPPTs
  • Cerbo GX
  • Shunt

Over the DVCC there is a current Limit for Battery. If the DC coupled feed-in is OFF, then everything is working fine and you can limit the current for the Battery with the DVCC Limits.

But if the DC coupled feed-in is ON, the cerbo-gx ignore the DVCC settings accordings victron manual and also tested in reality. The MPPTs need to be always on full power, to be able to feed in.

But how can i control now the Batterie current? Also the DVCC Voltage Limit doesn't work. This was my second idea, to adjust for example 45V Limit, then the Multiplus should move the MPPT Power into the grid, but it doesn't?!

I want to prevent overcharging the Batteries, so activate some current or Voltage Limit, that the Batterie will not rise up more and more. Doesn't matter a few amperes in or out, but should be around +-5A. So the MPPT power should be used for the house + grid if the shunt shows 100% and then the multiplus should control the shunt current to 0A.

Is there any parameter to write in Node-Red to Limit the battery shunt current? Normally DVCC, but system doesn't listen to it with DC-coupled mode! Thank you a lot!

kevstone122 asked
wolferl answered ·

16 Answers

MPPT power is limited for DC feed in if battery is full

Setup:

MultiPlus-II 48/3000/35-32 / FW: v501
BlueSolar Charger MPPT 150/35 rev3 / FW: 1.61 with 2kWp solar panels
GX Device / FW 2.92
48V CAN Battery connected to the GX device
EM24 Ethernet smart meter
PV inverter at AC IN


I have configured ESS with DVCC for the system. As long as the battery is charging, the MPPT provides full power (even if battery takes less power than the MPPT provides). But as soon as the battery is full and the excess power shall be feed in to the grid, the power of the MPTT is limited (about the half of the theoretical available PV power.

Battery is charging (MPPT DC power is 1021 W):

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Battery is no longer charing (MPPT DC power is limited to 602W)


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Do you have any suggestions?

Best regards

Michael


This is my configuration:

DVCC

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ESS

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blackmarlin asked
astrayan commented ·

15 Answers

Peak shaving while charging from grid

I am looking at buying a Multiplus 48/3000/35-32 with the GX controller to combine with a 16kWh BYD battery and solar panels. I looked through the documentation but could not find information on my use case.

One of the reasons that I want to buy this setup is to do peak shaving. From what I understand from the documentation, the default setting is that you do ‘peak shaving’ when the battery is full but that it will shave to (close to) 0W. When the battery is depleted, peak shaving will stop and you will go to the grid for 100% until the PV charges the battery again or you specify a charging window from the grid after which it will resume.

The issue I have with this setup is that (most probably) next year, we are going to be taxed based on the maximum power demand from the grid in a 15 minute window over a month. So using 10kW during 15 minutes anytime in the month will determine the amount we are taxed and each higher peak value will be much more expensive than the lower one. The goal for the peak shaving would be to reduce this maximum peak but when the battery would be depleted early in the afternoon, generating a single high 15‘ peak in the evening at any time during the month will make the battery investment worthless for this purpose.

I did find that you can set the grid power but that seems to always apply and in December for instance, I have days that only 10kWh is used at the moment but also days with 50kWh. Setting the grid parameter to 2kW would mean that the battery is not used at all during the 10kWh day but would still be depleted after a few hours on the 50kWh day in turn causing a power peak once the battery is depleted. As the goal is also to use the battery to charge during the off-peak hours and use that energy during the day, not using the battery on the 10kWh day will negate the benefits of the cheaper off-peak energy cost.

My question now is: is there a way that you can set a certain limit (e.g. 40% charged) after which the battery starts charging from the grid at e.g. 3kW up to e.g. 70% but when there is a total power request from the grid of e.g. >6kW during the charging, it will kick in and deliver the requested power above 6kW and starts charging to the requested limit again once the power drops below 6kW? When the charging is done, it can return to 100% peak shaving to (close to) 0W down to the 40% level at which the charging starts again. In short, I want to set a limit on the power drawn from the grid at all times and the battery would have to do peak shaving when the demand is higher and charge itself (from the grid if there is no PV) to a certain level when there is less demand while still offering the peak shaving during the charging.

If this can be done through an API or other interface that would also work but (again, from what I understand) the battery would not be used at all during a charging window which might again lead to peaks while charging which is what I wanted to avoid. If this is not possible now, do you think this is something that can be included in a firmware update in the future as for the Belgian market this would be an extemely useful feature starting next year?

tubeman asked
Stijn Dhondt answered ·

4 Answers

Does Dynamic cut-off make sense for Lithium systems?

Dynamic cut-off is an option only available on systems running as ESS, i.e. the ESS assistant has been installed and configured on the inverter device, and there is a GX gateway present on the system.

AFAIK, dynamic cut-off exists so as we can set a lower cut-off voltage for when there is a large current coming from the battery, since the battery has not actually been discharged, but all that's happening is extra voltage drop due to internal resistance and such, i.e. when the load is lifted, the voltage wire rise considerably.

So, I guess dynamic cut-off makes perfect sense for lead batteries, where -for example- you could safely pull a 12V lead down to 10V when there is a 2C load on it.

However, in my opinion, dynamic cut-off doesn't make any sense for Lithium batteries. Why? Because Lithium batteries have a build-in BMS that will block discharging when the battery's minimum threshold (or a cell's) is reached. This will definitely happen when there is a hard load on the battery. So, it doesn't make any sense to adjust dynamic cut-off for a lithium battery at a lower value than the battery's BMS minimum voltage setting. That said, it doesn't make any sense to enter a higher value, either.

So, what's the point of dynamic cut-off for Lithium batteries? Please elaborate.

thanar asked
thanar commented ·

3 Answers

SOC decreases in ESS during excess PV feed in

I'm running an ESS system according to the following picture:

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PV inverter 6,9kWp, PV charger smart solar 100/50 0,7kwp, Multiplus 12/1200/50, 12V 400Ah LiFePo, Smart shunt 500, Gridmeter EM24, PV meter ET340.

Generally the system works as intended.

But what really makes me wondering is the status "Discharging" combined with decreasing SOC during the phase "DC-coupled PV - feed in excess".

This leads to low SOC values including switch off when reaching my 40% limit while the battery is still above 13,2V = 100% SOC.

So my question is, have I missed a button to correct this behavior or is this a bug?

miguel5 asked
miguel5 answered ·

1 Answer

Is this a normal ESS behaviour

Calling out to the collective brain trust on this forum, hoping to get some glimpses of wisdom back that would help lead the way for me :)


About two weeks ago, I switched on my newly installed a three-phase MultiPlus II system in my house for the first time. Pure excitement. The ESS system and I are currently in the getting-to-know-each-other phase. It's mostly nice, but some of the excitement has tapered off and instead transitioned into uncertainty.

I understand that the job of the ESS is to try to keep the grid meter close to its set-point, and that this can be done with or without phase compensation. Something feels off though... I have nothing connected on AC2. Beside the pool which is connected on "the grid side" everything else, the whole house is connected to AC1. Despite this, at first, the Cerbo/VRM showed Phase 1 and 3 under Critical Load, and Phase 2 under AC loads?!...

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When changing grid metering under the ESS settings to Inverter/Charger, now everything shows up as AC loads. (see last picture for how that looks) ...


...but...


...when setting the virtual switch on the MultiPlus:es to On I become the neighbourhood's electrical grid equivalent to a wave machine at a water amusement park. Phase 1 and 3 are gently bobbing along with a few hundred watts up and down while Phase 2 is oscillating widly between +2,5KW <--> -2,5KW (roughly)

[image]


Even when setting the ESS mode to "Keep batteries charged" phase 2 seem to think that it's suitable to start discharging and sending 2-3 KW back out on the grid...

[image]


Only way to cool things off and maintain a more steady flow of electrons is to flip the virtual switch back to charger only.


... and now, to tie it together with the topic of this thread; Is this normal ESS behaviour ... or have I done something wrong? Is something faulty? I'm using a EM340 meter (The EM24 seems to be the preferred choice in most cases), could that have anything to do with it?


Any essential information that I left out, please enlighten me.

Any suggestions, insights or just some friendly cheering no to loose hope will be very appreciated. :)


Best regards,

Martin

odnacon asked

0 Answers

Setup a schedule for inverter power limit on an ESS system?

I am trying a way to better utilize my battery. It turns out that limiting inverter power during the night, allows me to keep the battery from overloading and switching to sustain mode.

So, question is, is there a way to set up an automatic schedule to enable and disable inverter power?

thanar asked

0 Answers

ESS mode - cycle battery

Hello technical specialist,
ESS mode, BMZ-battery, AC-output Fronius Primo, MPPT Smart Solar. All the latest updates.
The system works to offset surpluses and as a backup system with minimal SOC maintenance.
It is normal to see graphs that the battery cycles by +/- 3%.
If I have a minimum SOC of 60%, then the MPPT Solar power goes to the battery at about 63%.
Then the battery will be consumed and again 60% will start again.
Is this a normal system property of the ESS system?

Thank you for your time
Ondra

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solarhome asked
rogio commented ·

3 Answers

ESS - Grid consumption is high and PV limited when battery soc is 100%

Please can soumeone help with my home instalation? I have 3phase system 2x MultiPlus-II 3000/35-32 and 1x EasySolar-II GX 3000 with MPPT250/70 for east PVs 2,7kWp and MPPT 150/35 for west PVs 1,8kWp. 2x pylontech 3.6kWh 48V

I use ESS asistant with regulation for each phase. Grid setpoint is set to 100W. But regulation doesn't work well. It use grid when it is no neccesary. When battery is 100% soc grid setpoint 100W is not reached. When battery is under 100% grid setpoint works fine.

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michalc187 asked

0 Answers

Settings multiplus ll and ess

Sorry for writing mistakes but english is not my own language.

I have an multiplus ll 5kva system with a cerbo, mppt's and 60kwh battery running a 230volt system.

My grid connection is 1 phase 16 amp

To peak shaving above the 16 amp is working perfect or the ess function is also working perfect.

My idea is use both of the functions together! Now i am doing that in a way when my battery is on 30% i set my maximum grid use on 2kw so the inverter is always able to give feed al the extra power that is needed. When the battery is full agean i set my maximum grit use back on 50 watt. In summer time i have enough power from the pv charge my battery every day full (or about full) but in the winter it is not enough.

Is it possible so to link the grid setpoint to the soc of the battery, for example

- soc 40 / 100% grid setpoint 50 watt

- soc 20 / 40% grid setpoint 1500 watt

- soc 5 / 20% grid setpoint 3000 watt

Or even more steps.

Is this possible or is there a way to make this work?

richard-veghel asked
sharpener edited ·

7 Answers

Multiplus II 48/3000/35-32 and CEC Approval (Australia) - ESS Not Allowed

Multiplus II 48/3000/35-32 Inverter is CEC listed as approved as Stand Alone Inverter With Generator Input Battery Only. This means my local electricity distributor will not allow it to be grid connected in an ESS configuration.

The approval certificate is Certificate SAA181339.pdf.

That certificate shows compliance with:

IEC 62109-1 Ed 1.0,
IEC 62109-2 Ed 1.0,
AS 62477.1:2016 and
AS/NZS 4777.2:2020 Inc A1

The CEC document CEC-inverter_listing_categories_2021.pdf (p2) indicates the Multiplus II 48/3000/35-32 Inverter meets the requirements as a Multiple Mode Inverter and hence approved as a Grid Interactive inverter.

As I have just acquired 2 Multiplus II 48/3000/35-32 in Jan 2022 for use in a parallel ESS system with Fronius inverter on AC1 Out, this has become an issue.

Is there any reason the Multiplus II 48/3000/35-32 Inverter is not listed as a Multiple Mode Inverter?

bipedalprimate asked
johnone answered ·

4 Answers

ESS-wizard niet gevonden

Na firmware updates geeft mijn multiplus II GX bij de instellingen voor ESS: "ESS-wizard niet gevonden". Heeft iemand een idee hoe ik het ESS wel kan benaderen of installeren?

haddock asked

0 Answers

Understanding and improving ESS charging performance - timeshifting MP2/Pylontech

I'd like to better understand how charging is managed and hopefully find a way to improve charging speed if possible. I have a four hour cheap rate window in which to maximally charge my battery stack. It is problematic to get the system close to fully charged from its minimum SoC. System is 2x parallel MPII 48/5000/70 with 6x Pylontech US5000.

If I understand correctly, the charging process or, at least the overall parameters for it, are mostly managed by the Pylontech BMS. From the victron doc it clearly states the dynamic charge voltage and charge current limit (CCL) are controlled by the Pylon. I don't however understand *what manages the overall charge current supplied* at any given time. The CCL certainly changes, but only when charging gets close to full SoC ~90%, or if the battery is particularly cold. The system charge level rarely gets close to the CCL.

Looking at the graphs, during the ESS scheduled charge window, charging seems typically to have three phases - an initial relatively high level until ~1.5hrs in and around 50% SoC, then a medium charging phase that bounces around, and finally a very slow charging rate as we approach full past 90% SoC.

What part of the system controls the charge current level?

Why does it drop from the higher current charging to the lower after ~1.5hrs / ~50%?

Is there any way I can influence this control algorithm?

Perhaps the Pylontechs or Multiplus' are doing thermal management to an extent - though it doesn't seem that warm? Pylontech charge derating is supposedly only active outside of ~12C and 43C.

Appreciate any insight into the charge algorithm, and/or comparisons with other peoples systems.

Cheers, Paul.


A good night - starts at 16% SoC and gets to 98%:

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Not so good, start 11%, finish 88%:

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Start 11% end 92%:

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Start 11%, end 92%:

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Final example, start 34%, end 98.8% (highest ever seen):

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Paul Beskeen asked

0 Answers

Prioritizing PV for charging routine.

I am planning my ESS.

I have 3rd party MPPTs directly charging the batteries through a BMV.

There's a Quattro with loads both on the AC in and the AC out and a CG meter preventing export at the grid connection point.

I want to optimize self consumption, but I want to prioritize the PV for loads and charging the batteries during the day. Using the grid to supplement loads.

I only want to use the grid for charging from late afternoon onwards, say if a set SOC criteria has not been achieved during the day.

However at night an acceptable amount of discharge will be allowed to a lower SOC.

In other words, I want my batteries fully charged ready for the night, every night.

I want to cycle the batteries during the night, and I want solar to be given priority to re-charge the batteries the next day.

Can it be set up like this?

Phil Gavin asked
roedolfdel answered ·

3 Answers

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