I use frequency shifting by a MultiPlus 48/3000/35-50 (firmware v430, off grid) to control electrical heaters via an AC Thor controller. The idea is to maximize PV power consumption. Layout:
My MultiPlus setup is the following (full settings attached):
Absorption voltage 55.50 V (absorption voltage of set MPPT = 57.4 V)
Float voltage 55.10 V (MPPT float 55.2 V)
PV inverter support assistant settings:
*) The solar converter will start reducing its output power at 50.10 Hz.
Output power will be reduced to minimum when the frequency is 51.00 Hz.
The converter will disconnect when the frequency is higher than 53.00 Hz.
*) Total installed PV inverter power is 1500 Watts.
Total installed PV panel power is 1500 Watts.
The issue is that the MultiPlus frequently gets stuck at the maximal value of the frequency control range, i.e. 51 Hz. So not at the "disconnect" value of 53 Hz, which seems to be reset according to what is written in the documentation of the PV inverter assistant (at a voltage equal to Float V - 5.2 V).
An example of this issue is shown in the graph below. At time = 0 h (midnight), the system is already stuck at 51 Hz from the previous day (green curve), despite the fact that the battery voltage is 49 V or lower (blue curve), which is well below the charger absorption voltage setting of 55.5 V (dotted blue line). I had switched off the AC Thor loads the previous day, to avoid battery draining.
In the morning I remotely reset the MultiPlus to get the frequency back at 50 Hz.
At around 12:00 pm, the system did what it should: when the battery voltage increased above +/- 55.5 V (blue curve), the frequency shifted. I switched on the loads again, and AC power was sent to the heaters by the AC Thor controller (red curve). I have two sequential heaters of different power controlled by the AC Thor, explaining the variation in AC power consumption.
One can also see that at the end of the day, around t =18 h , the system again was stuck at 51 Hz (and so power consumption maximal at 1500 W), despite the fact that there was not enough PV power available and that the battery voltage reached values as low as 48 V. This is far below the absorption (and float) voltage set for the MultiPlus charger, so one would expect the frequency to be shifted back to 50 Hz. The battery was drained to 80 %, at which time the AC loads were switched off automatically by a Multiplus relay that I programmed for this purpose.
The problem is of course this behaviour drains the battery unnecessarily.
Weirdly enough, the issue does not always happen. Many times it just works as it should (see bottom graph). I did not find any regularity, except that it seems to happen on days with alternating sunshine/clouds, and after the Multiplus returned from the "disconnect" frequency, 53 Hz in my case. Similar behaviour has been reported a few times before on this forum (mostly in the context of frequency shifting for AC coupled PV charging) but a definitive solution was not given.
Can this be solved by changing the settings somehow? I tried many charger voltage/ frequency range settings already, but always the issue pops up. Or is this inherent to the way the frequency shifting is programmed?
Multiplus settings: MP_settings.txt
A good (sunny) day - example of how it should work:
ive recently had a new system commissioned and I am struggling to get the Quattro to frequency shift for the AC Thor to kick in, we added the PV assistant in VE Configure and left the default settings, batteries are 100% and sun shining bright, I have 12.7kw of Solar panels with two 250/100 MPPTs.
Batteries are two sets of BYD 13.8.
Can anyone see what I’m doing wrong, AC Thor is set to frequency mode.
I wondered if there are anyone out there who knows about setting up MPII Assistants in VE Config.
Setup: MPII, CerboGX, Lifepo4 batteries.
Would anyone know how I set up assistants to Turn the Charger on at a certain time and then to turn if off after a few hours - e.g. Inverter ON at 8.30pm and Off at 1.30am?
I am from Czech Republic and I have following device setup:
3x MultiPlus-II 48/5000 in 3-phase configuration
DC coupled system with PV array (2 strings, 2 MPPTs)
VenusGX - devices are connected to the VE.Can (Battery & MPPTs) and VE.Bus (Multis)
Next, the software configuration:
VenusOS version: 2.92
Multiplus-II firmware version: 500
=== Multis settings: ===
The same settings on tabs: General, Grid, Inverter on all Multis; Charger settings only on L1 Multi
Grid code: "Europe (EN50549-1:2019)" on all Multis
== Assistantants: ==
ESS on all Multis
generator start and stop (load & battery SOC conditions on L1, load conditions on L2, L3)
general flag user
Goal of configuring assistants:
To be able evaluate load on L1, L2, L3 and based on defined conditions set "Ignore AC" to off and take additional power from grid.
So far I have been working with a 1-phase installation - it has worked well. But in this 3-phase system it doesn't work, no reaction on any assistant conditions.
Is there any recommended/supported settings for this solution?
I have used mainly following documentation for my setup:
Victron & Pylontech US2000, US3000 and Phantom-S [Victron Energy]
Thanks in advance for the responses and advice.
is it somehow possible to program a time delay for the Multiplus (in an ESS system) before it switches back from battery to grid in case of an power outage?
In case of repair works on the grid I observed, that the first few minutes are often not stable and so the Multi switches to grid, back to battery then again to grid....
Is there a way to program a delay with assistants(?) with the goal to switch back to grid operation only if the grid is present continuously for about 5 minutes?
I have a hardware solution in mind but a software solution would be much more comfortable.
I'm pretty sure I know the answer to this. We have an upcoming system install with 3x Multiplus ii 5000/70 for an off grid install set up in 3 phase. The client needs 3 phase for about 4 hours per day. After that all loads are single phase with some bigger single phase equipment that will be used later in the day. These single phase loads are shop toold that maxes out a single Multiplus 2 ii 5000.
Can anyone imagine a way to have the system set up as 3 phase for part of the day and then paralleled for high load single phase loads the remainder of the time? I do realize that the actual wiring for the single phase will need to be creative if this is at all possible
I've racked my brain and don't believe it's possible other than increasing the number of parallel units but keeping the 3 phase.
I've got a system which I can't check on site if the disable fan logic is as expected.
It's not clear if disabling the fan for charge only will also limit inverter output maximum power, or just reduce the charge current?
Can anyone confirm if silence fans when 'charge' is selected just silences fans whilst charging and the inverter still has maximum power output with fans un-silenced whilst inverting heavier loads?
I expect fans will still come on when inverting heavier loads but I want to minimise them coming on for charging at the expense of the charge current.
This is for a DVCC setup holiday houseboat with a 6k Solar, Multi 5k, 4 x Pylontech US5000.
The main reason is the sound sensitive owner, and not being able to use assistants for disabling charger when ignore AC allows shore power to power assist heavy loads, but still have the charger enabled for cloudy low SOC times. - (Without a manual switch)
I have recently reconfigured some ESS Systems because of some changes. In VE Configure it wants me to update my ESS Assisant from ID 017E to 0184. However the assistants changelog in Victron Professional ends at 017E.
I also want to update the Systems to v.500 while I'm on it, but I am not sure whether I will run into problems without the Changelog?
Does anyone maybe from Victron knows where to get the changelog and / or if I run into problems with Firmware Version v.500 and 017E Assistant?
There was a problem posted here 10 days ago where someone couldn't get ESS running again after Updating to v.500
Upgraded 2x Multiplus II 48/5000/70 connected in parallel to Fronius 8.2 Primo, now with the upgrade have lost the ESS assistant.
I have been succesfully using the PV inverter support assistant of a Multiplus 2 to control an external heater (excess solar energy dump in off grid system) via frequency shifting. My system had lead acid batteries.
Now I changed to Pylontech batteries. Charge control is now done via DVCC.
This caused the PV inverter assistant to stop working. I can configure the assistant, and as long as I don’t plug in the VE.bus cable of the inverter in the Cerbo unit, it works: ac output frequency is increased by Multiplus, as expected.
However, as soon as I plug in the cable, and thus establish communication with the inverter, the DVCC seems to overrule the inverter and PV inverter assistant stops frequency shifting.
Is there a way to make this work?
My Quattro 48/5000 is connected to AC 1 with a Honda 2000i –AC1 current limit=15amp.
If I have a load of ~1400 W and my refrigerator starts, the load momentarily exceeds 15 amps and the “Power Assist” cuts in as it should. However, instead of AC1 supplying 15 amps and the balance coming from the battery, it splits the load approximately in half with ~ 750 W being drawn from the battery. This is a problem when the battery is in a low SOC because it drags the battery down when it should be charging. Also, even when the AC load reduces to below 15 amps, the “power assist” is still activated and stays activated –and taking power from the battery--until the load is significantly reduced to say ~300W.
Is there anything that can be done to correct this problem?
Not a Windows guy (100% Mac based) but would like to install an ESS Assistant. I have a Multiplus II, MK3-USB and a Cerbo. Is there a way?
Dear member of the community.
I have recently installed a Multiplus 24/1200/25 (which I will be updating sooner than later), and along with it, I have installed a micro-water turbine of 200W (AC, nominal voltage of 220). The problem I am having right now, is that this water turbine gives me frequencies between 63 and 38 Hz depending on the amount of energy I am generating with it, also de voltage ranges from 310 to 190 V, also depending on the energy generated.
I have read a bit about the 1140 Interface, but there is not enough information about it, for example, knowing which ranges of frequencies, voltages and current will be accepted by the assistant and also by the multiplus (given that the multiplus only accepts AC input of min 45Hz - 180V and max AC input of 65Hz - 270V. So, how would de 1140 work?
Also the problem, apparently, is tha the 1140 interface must be close to the water turbine, thing that is a bit difficult, because it is close to a river, (100 meters from the multiplus).
If there is another solution that is not the 1140 interface, please let me know. And if this is the only one, please explain to me how this works and how could I do it.
Thank you very much!
I have red many Victron documents, watched webinars and also searched through the Victron Community but was not able to clearly figure out how a Multiplus II behaves if no assistent is installed. Would be great if someone could provide some informations.
- ACin of the Multi connected to the grid, no feed back to the grid
- Critical loads connected to ACout1
- One Pylontech US2000C and a Cerbo GX
- no PV, no MPPT
a) Will the Multi keep the battery always 100% charged?
b) Will the load on ACout1 fed from ACin or from the inverter by discharging the battery?
c) In case of a grid loss, will the load on ACout1 fed by the inverter and battery?
- Same as scenario 1 but additionall with PV and MPPT
a) Will the battery primarily charged by the MPPT and in case there is not enough sun via ACin?
b) Will the load on ACout1 primarily fed by the inverter by discharging the battery and in case there is not enough sun via ACin?
Actually I would like to set up a self-consumption system with backup capability and the possibility to charge the battery with an generator in case of a long lasting loss of grid. For this an ESS seems to be the right choice. But Victron says, that an ESS should not be used in case of "Off-grid systems - either with or without generator". That surprises me because a long lasting grid loss leads to a kind of "Off-grid system".
Bonjour à tous
J'ai une installation avec des batteries BYD, des mppt, un multiplus II et... une éolienne. Le chargeur qui vient avec l'éolienne n'est bien entendu pas capable de communiquer avec le système GX et donc de profiter de DVCC, donc il faut trouver un autre moyen de piloter la charge de l'éolienne.
Pour cela, j'utilise un contacteur triphasé 63A NC qui met les phases de l'éolienne en court circuit pour la freiner quand la charge n'est pas nécessaire. Ce contacteur est relié à la sortie ACout2 du multi. C'est un contacteur NC par sécurité, donc ACout2 actif -> charge autorisée.
Je me sers d'assistants pour piloter le relais ACout2 du multiplus II de manière à piloter le contacteur. J'ai donc défini deux assistants relais :
1- désactivation (OFF) si SOC>85% ou si Vdc>56,5V pendant 4s
2- activation (ON) si SOC<75% ou si Vdc<53V pendant 300s
Ça fonctionne, MAIS je rencontre un problème qui est que même batterie > à 85%, si la tension baisse en dessous de 53V, le relais se réactive. Donc la question est : comment rendre les conditions "OFF" prioritaires sur celles de "ON" ?
En même temps au moment ou j'écris ce message, je suis en train de me dire qu'il doit suffire que j'inverse l'ordre des assistants... c'est bien ça ?