unfortunately I can not check if my surplus (MPP op mode) based control still works since the sun has gone now…
ok. now same situation now as ~20 hours ago, but at least not back behind like 12 hours ago 
oh, I just realized that today is Friday, 13th…
the control loop performance of the MP2 is horrible. setpoint constantly -131 - this ist what MP2 puts out (according to it’s own sensor, and according to the the grid meter it seems to be true)
ok, that’s enough for Friday 13th. why haven’t I bought just another Chinese Inverter!!!..
This is the over-all closed loop zero control (setpoint -10 Watts) performance using the Lumentree:
measured by the gauged(!) grid meter including the jitter of domestic consumption…
how should I ever achieve ‘zero’ feedin with an inverter scattering +30/-50 Watts at a setpoint of 130??? Who the hell ever told that the MultiPlus II is a good inverter??
Friday 13th…
does anybody know what this is?
may this help?
does not help. but reducing the frequency of refreshing setpoint seem to help: 3s → 10s:
Good morning everybody!
during the night I solved the output jitter problem by setting the MP2 output ‘stepwise’, so with small loads it does not interfere with my zero control.
But now the sun is back and the next problem comes back, too: As soon as I switch on the MP2, the ESS Assi sets the target charge voltage down to zero and the chargers stop working even SoC is down at 69%. 
Unfortunately now I first have to charge the battery so I can’t do further testing until SoC is up again. So MP2 and Assi must stay switched off and while that I can’t read or change registers…
@M_Lange Matthias, you seem to be familiar with the Assi settings
- do you see any setting that might cause the disabling the chargers?
- do you have an idea what I can do to keep them running and keep control of the charge voltage by my charge control algorithm?
Might the setting ‘sustain voltage 45V’ be the reason that the assi switches off the chargers?
Will it be a solution to change that to 54V and disable the MP2 charger setting register 38 to 1?
or will that disable chargers ‘system wide’?
What does “Disabling charge will also disable feedback.” mean?
Why is register 38 still 0 since I disabled the charging in VEConfigure??
thank you!
oh men, I could cry! I simply want to control the power output of an inverter. To do that I have to connect the inverter to the system and activate an oversophisticated ‘assistant’ to make the most basic functionality of an inverter available. But this ‘assistant’ takes contol over my system and destroys everything I achived.
It is now day #4 that the inverter could power my loads but since 4 days but I’m struggeling to make it putting out power as I want and not doing what I do not want it to do (e.g. take control of my chargers).
Is there a way to command the inverter ‘isolated’ from the system? so not to connect it to the Venus and communicate directly? (like I do with the Lumentree)
I read that the MK3 protokol is ‘not trivial’ so hard to implement. If I would take that challenge - will it be possible just to command the output setpoint?
After what I read here you are much better informed in this matter than I am, but I control and monitor the installation with Node-Red. It can’t get any easier than that, I think?
hi @Diederik , thank you! I think Node-Red (Venus large) is no solution since there are proprietary components with proprietary communication (no adapter) in the system required in time ‘critical’ closed-loop control. I did not try with Node-Red, but with Home Assistant (java script) it was dead end quite soon. I can’t imagine that with ‘graphical programming’ or yaml it will be easier…
It is not simply setting some flags or values commanding just something. It is a system with a sophisticated control loop core and lots of proprietry components and code…
ps. ‘commanding’ the MPII from Node-Red would not solve the issues with the overpowering edgy assistant… (I guess)
Aspects that do not harmonize are
- the other inverter Venus does not know and does not ‘see’
- my way of using PV surplus differently from only feeding into the grid
- my charge controlling to e.g. 80% SoC during summer
- the 3~ energy meter not supported by Venus
- …
Sounds interesting. Good luck with the solution.
@alexpescaru Alex, do you know where to find the https://community.victronenergy.com/storage/attachments/29992-presentation-ess-systems.pdf nowadays? the link does not work anymore and I like to completely reset my MPII. Perhaps that might help solving the ChargeVoltage-set-to-zero issue…
Don’t know, but maybe this helps: Victron MultiPlus ESS Einrichten einfache Anleitung
What is your grid meter update frequency if running closed loop control with external grid meter? Most meters are very slow to provide measurements so you never be able to settle set point. In the end that not really matter if don’t change setting too often as net metering will balance out during net period.
Do you have topology drawing about your system design and how control loop intended to work?
hi @JaniEronen !
sorry I was so busy with the other thread that somehhow I missed this… I do not hav no drawing but here the setup is described short and sweet.
The control loop is not easy to describe (in fact it is not only one…).
Inputs:
- grid power
- SoC
- MPP operation mode
- domestic hot water
- battery voltage
- battery current
- gradient of load change / pulsing of load
Outputs:
- inverter setpoint(s)
- charge voltage
- dom hot water heating (3 stages, 50Vdc)
Priorities:
- zero consumption
- accu 80/85% SoC (at least during summer)
- dom. hot water hot
- surplus feedin (up to certain level, officially I’m restricted)
SoC control done in a simple extra loop limiting the charge voltage in case, otherwise charge voltage ‘curve’ from BMS
The power control loop is quite complex since it acts e.g diffferently to different gradients of load and on switching/pulsing loads depending on winter or summer. the algorith is several hundred of lines of code.
You are right, the grid meter signal is some kind of slow, but in Germany we are restricted to 400W/s gradient so you can not 100% compensate a kettle getting switched on anyway. The 1.4kW pid expresso machine pulsing in sub-second frequency is even harder (impossible with 1 Hz grid info), this is why I’m doing different in summer/winter. The MPP operation mode also reacts quite slowly on a 280Ah battery, but in general it works quite well even i’m still working on it…
but the original question was how to get the inverter doing what I tell it. this we figured out in the meanwhile (ESS mode 3) and we also managed to keep the solar chargers charing when an ess mode 3 inverter connected to the Venus OS (this took 4 complete days and the only solution seems to be a small Venus mod, I think there is a bug…)
thanks Alex @alexpescaru I will have a look at the linked stuff even we got a lot further in the meanwhile
@JaniEronen one question, please:
If I would connect a faster meter like Carlo Gavazzi or Victron and use one of the self consumption ESS modes, would then the ‘internal’ power gradient be higher? like
consuption: 0->100; MultiPlus: 0-> -100 => gradient to outside: ~zero (similar to if operated in island mode)
or will there still be the grid code limitation active to MP2? In other words: Would the gradient limit apply to the grid connection point or to the inverter output?
thank you!
Hi not sure if it helps BUT
using CT, Multi will compensate sudden demand from battery an then balance to settings.
Using external meter Multi will use grid then ramp up to settings.
One can set charging @ DVCC
Setting of multi inverter power is in ESS but see above.
These should be avail via MQTT
I use a custom written scipt based on openhab sycle on demand changes of more then 5-10% with priority on SoC, excess to boilers, towel heaters, underfloor etc…
As I am on a rural net 202-238V it is impossible to balance to zero
Hi Martin @LifeInGalicia !
thank you. I think this is a different aspect since you seem to utilize AC-out, right? So not comparable with my current architecture (AC-in in grid-parallel only).
>> As I am on a rural net 202-238V
hihi, I remember these times in the 80’s while my communitiy service when we had to manage a small ‘castel’ on Cap de Creus, Cadaques, Girona, where electricity disappeared every second day (no PV these days…), house connections made by speaker cables (not our one but down in the city)… or my parents living in Jaraiz de la Vera, Extremadura, - also adventurous installations could be found… 
enjoy!
Hi I use Mikros combined to three feed in points before and after the Multi and an external CT supply point. It powers three houses only mine is direct on AC out 1 - Works well
As I pay for it I use my 3Kw allocation to shave peak loads.
hm, I think I did not get you really right - you said
but you do (red line in your graph)?!?
Could you pls describe your setup a little bit more in detail?!
- which ESS Mode?
- external grid meter connected? where? which/how?
- three houses?
- Micros?
- …
thank you!
Hi
red line resolution not showing -20 - +90 W draw from grid - setting is 40 W - peak demands fed from the grid do happen as well as the inverter is limited to 1Kw.
I have an external CT (Victron), extended by 5 meters, connected to the grid feed line after meter berfore distro panels.
My house and two holiday houses, which bypass the Multi .
I use type “Balkonkraftwerk” one to four panels on a Micro inverter connected to three different feed lines. Before the Multi and after the Multi (Rule 1:1). So all is AC cabling.
https://www.lemosverde.com/wp/solar-powered-life-lifeingalicia
Its work in progress so contains spelling mistakes etc.
ESS basic without battery life (I think)
Black start is not correct I have a feed in after Multi on AC out 1 (1.5Kw / Rule 1:1) to sustain bat when no grid.