I also have the case of some light small feed in from grid without any reason (enough solar and battery for my loads). And I would like to avoid this behavior as well.
No feed from grid as long as solar and/or battery are able to feed the loads (until battery reaches a set low soc from when the grid would start to feed the loads)
What am my missing in my settings ? Should this a non native type of need, can node red be used to control the unit that way ?
(Note : I am coming from a Chinese inverter with some basically SBU / LBU settings that were obvious to use).
You are not missing anything.
All is OK, maybe you just need to increase a little the grid setpoint to 50-100W, as described in the ESS manual, at page 11 (4.3.12), in order to avoid feed-in.
As long as the AC-In is connected, you cannot reach a perfect 0W on the input, because of the dynamical consumption of your loads.
The grid is used just like a small buffer from which you draw and dump the variation of your loads.
Just like a car in busy and/or slow traffic. You canāt maintain a perfect average and constant speed. Sometimes you are accelerating, sometimes you are braking, even stopping, if you get my analogyā¦
To avoid feed in, raising the grid point helps but create a permanent drain from grid - which is not really good as well
If I cut the ac in, all my load are battery and solar powered without any problem - thus I do not understand why, when grid is connected, there is this drain from grid to the loads through the inverter.
Isnāt there a way to control the system to simply disable the ac in for such purpose and enable it under some conditions ?
@Marc
This is noted. However,
My grid subscription have some āredā days where electricity is very expensive - this is typically the days during which I will charge my battery during the previous night (taking into account forecasted production for the day after) and for sure, I do not want to get anything from the grid from 6am to 10pm.
I used to be a developer and learning Node Red since one week.
Globally, no issue with the logic and way it works.
I made some flows to capture some external data through APIs and MQTT and send them in MQTT to feed some flows or home assistant.
However, I have not played at all with anything related to Victron, for which I am total newbie
The Victron MPPTs are quite slow to adapt to rapid changing conditions.
If there is a sudden increase in requested power, the Multiplus, besides solar, has 2 choices to supply that sudden increase: Battery or Grid.
Inside a Multiplus there is a bidirectional AC/DC converter.
When this converter is working from AC to DC, then the Multiplus is in charging mode.
When this converter is working from DC to AC, then the Multiplus is in inverting mode.
Donāt confuse these modes with the menu configured working mode.
Now, back to that sudden increase in loadsā¦
If this increase in requested power will find the Multiplus in AC to DC conversion mode (charging), it will first have to switch to DC to AC conversion mode (inverter) to compensate the increase in loads.
This is taking time, so up until the switch, for a seamless operation, the Multiplus will draw a small amount of power from grid.
Hope that is now a little bit more clearā¦
In short:
Up until the Multiplus is adapting to the new loading conditions, the easiest way to supply the loads is from the grid.
If your REALLY donāt want ANY draw from grid, the sole, CLEAN, solution is a controlled AC-In ignore.
setting MP2 mode switch to āInverter onlyā to avoid any AC-in exchange (either in or out)
setting MP2 mode switch to ON, base on VEBus system node triggers (such as load power, battery SOC, or anything else needed)
possibly setting the ESS active SOC limit to a desired target to be reached when in ON mode to charge the battery using AC-In
Correct ? If yes, nothing that looks unachievable (just had a look to those nodes).
I guess the āinverter onlyā mode is actually turning off the AC input relay, right ? (so the above is the same approach as the AC in ignore virtual switch assistant in VEConfig)
AC-in ignore will deactivate the AC-in relay. Itās just like you unplugged the AC from the input of the Multiplus.
Inverter only will configure that internal bidirectional converter to work only on inverter mode, meaning only DC to AC conversion. Grid is still present and then the inverter will add to the grid for a āPowerAssistā mode.
OK for AC in ignore - very clear. It is an extreme cut from AC.
For inverter only, as the AC-in relay remains on, this keeps the possibility to handle some power peak from loads when needed, aggregating to AC-out 1 the battery power (through inverter) + AC-in. If yes, I guess this is the feature I may use most of the time (better to feed from AC in extreme condition rather than having a blackout at homeā¦ will avoid family issues )
Will try to play with both to better understand. I still need to find out how to control āAC in ignoreā from node red for this
I have frequently -1, 0, 1W consumption. In my energy supplier I have zero injection and zero consumption.
I donāt have ESS, Iām in auto consumption or off grid, canāt remember now. Iāll check when Iām home.
Do you need ESS?
Honestly, Iām starting in the complex Victron world, so this is a very good question.
Iām used to control my previous dumb chinese inverter using some defined rules & home assistant. I plan to proceed the same type of control loop with my Victron unit using Nodered.
Those conditions are considering some external conditions related, among others, to the grid cost (some days are qualified as āRedā, really expensive between 6am and 10pm for example).
Basically the scheme is as follows:
@10pm: if the next day is in the āredā category, charge the battery to a certain level (the level is set depending on the forecasted production on the next day) - to ensure a full off grid during this day
@5.59am: go off grid (avoid expensive hours)
whenever: if battery is low state (5% SOC), charge it up to 30%.
3.1. If such a situation occurs between 6am and 10am, switch back off grid once charged.
3.2. If such a situation occurs between 10pm & 6am, feed the load until case #2 above occurs
Unfortunately, the French EDF Tempo is not listed and cannot be integrated by a simple formula, but thanks for the pointer.
EDF Tempo is built on a complex & daily-based dynamic: it is a 6-prices grid, with the applicable prices for the next day (from 6am) known the previous day no later than 11am - next day information being caught using APIs (something I achieved to do in Node Red already).
Indeed, I may rely on DESS, but as this means I would push some stuff using Node Red to configure it, this moves away the āease of useā DESS could be expected to bring.
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