question

Hi

Need more details of what type system you have off grid, grid tie etc, battery type etc.

@Rob Duthie

This is how my grid tie system looks like.

Multiplus II ignore the grid except when SOC <30% when it start to charge the battery form the grid up to 50%.

Battery LiFePo4 230Ah connected to MP2 with 2x2m(6ft) 50mm2 welding cable.

Hi

Are you connected to the grid at all? if i was you run the ESS assistant ignore the PV inverters not required.

What country are you from installed?

@Rob Duthie

Grid is available, MP2 is physically connected to the grid to charge the battery if is not enough energy from the sun.

Grid fed in is allowed only for prosumers which I am not yet. From that reason I cannot use ESS and grid connection in this phase.

I will try ESS without grid connection to see if the system is stable.

Thank you for the hint.

@Rob Duthie

The charging-discharging is still there.

The MP2 is set with ESS and Fronius set to MG50 is connected at AC Out1. AC In is disconnected.

On every 3 to 5 seconds the MP2 is switching the current flow direction as below:

All the loads are connected to AC Out 1

Cerbo GX and MP 2 48-5000 firmware are up to date.

If all loads are connected to ACout1, why are there no critical loads shown? is the inverter ac output in use enabled?

@Baxter

AC Out1 is critical (essential) load. My microgrid setup looks like this:

AC Out 2 is with relay and is not enabled and not connected.

More about the issue:

And what GX device is showing:

You are writing that all loads are connected to ACout1, so critical loads or no break loads. If you are running ESS enable the inverter AC output setting

@Baxter

I did the settings you indicate but charging/discharging the battery is there

Same issue...

I've got a similar problem. Battery is charging and discharging in the same setup as above. I've found when I disconnect the grid meter, then the inverter changes to passthru and the battery state is stable again....

With or without meter, is the same.

Yesterday I found that if the production is high enough (>800W) charging quasi constant and the system is stable.

To be continued ...

I found today that the AC voltage is fluctuating when the system becomes unstable.

The bulb lights flickering.

Another stability issue ESS microgrid AC coupled PV inverter connected to utility grid.

Fronius Zero feed in = Yes in Cerbo GX so modbus tcp communication are ok (and hard wired not WiFi)

This is anything but zero:

The load is around 115W and in the what is showing in the AC Load tile is actually the power that both PV inverter and multiplus are feeding to the grid. I measure the AC In1 current and the measurement confirm it but Grid tile say "0".

And this with AC in disconnected from the utility grid and

Fronius Zero feed in = No in Cerbo GX.

Have you encounter this issue?

Any suggestion where this is coming from?

Thank you in advance.

Temporary Solved using 3.5mm jack trick!

Continued here:

https://community.victronenergy.com/questions/136049/critical-load-shows-high-values-how-can-i-check-th.html

Dears,

Off grid AC coupled microgrid issue is still not solved.

AC voltage is going up and down 2-3 times per second between 210 and 240V

This is happening only when solar power is low (<800W) and close to the load, way before Multiplus is starting to increase the frequency to control Fronius.

Actually when frequency shift starts, the system is very stable.

Fronius PV support was involved. They want to install older firmware in the Primo but it looks that Primo does not accept that old firmware version (32071). They tested the Primo uploading the current firmware 33151 version via web and works fine. I did it via USB and works just fine.

Fronius PV suport team doesn't come back to me with a firmware or other solution. Maybe they are working on a firmware but it is a week since last mail from them.

Bulb light flickering is only the annoying part but charging and discharging the battery 2-3 times per second at +/-10 to 30 Amps half of an hour or more everyday it cannot be something good for the battery.

Above, Rob, suggest to ignore PV inverter in ESS.PV inverter is already in place. Maybe I will add an another Mppt Controller and more panels in the future but now I have to deal with microgrid and this Victron - Fronius mix of species.

Any idea?

@shaneyake

Thank you for explanation. You confirm that my understanding based on ESS documentation and webinar is correct.

The size of Primo is 5000W and size of Multiplus is 5000VA the battery is LFP 230Ah

Flickering issue is taking place where is no frequency shift at all and PV power is <800W.

Looking closer, AC output voltage variation is dependent on PV power. Lower the power higher the AC pulse amplitude and less pulses per second. Close to 800W the AC voltage is pulsating faster (10 times/s) at lower amplitude. If PV power increases above 800W no more flickering.

While AC frequency is 49.9 50.1 Hz.

Today is a sunny day and PV power is above 800W already so I miss the opportunity to do any tests.

Any suggestions?

@shaneyake

Zero fed in feature is used when Multiplus is connected to the utility grid. Then Victron cannot change the frequency of the grid and Fronius is throtled by Victron. This is working just fine.

In off grid mode, the flickering issue take place when Victron let the PV inverter to provide all the power from PV and frequency shift does not start to throtle Fronius.

The newest Fronius firmware fro33160 has some effects on the AC pulsation issue:

- starts at 100W PV power vs <100W,

- ends at approx 500W, and highest pulse amplitude is close to 250W PV power vs. 800W and 400W max amplitude;

Much better but not as it should be.

Nobody want strange noises from the fridge and strange lamp flickering without considering other aspects.

I will contact Fronius and Victron again and again to solve the issue. They offered this microgrid option, I did a choice based on that, they should make it work.

Thank you .

Update.

Nothing good happened. Fronius Tech Support contacted me by mail.

They tried to upload the firmware 32071 via Web but they failed. They send me the file 32070 for USB upload but I got error 743 and 735 from Primo.

Finally I got the message from Fronius that they have in plan to solve the issue by the end of October 2022.

Update

Fronius PV support contact me again by mail.

They really do their best to help me to solve the AC voltage fluctuations.

They admit that the firmware version 32071 is not accepted by new Primo's.

They send me a fix procedure and code to access the menu where I can tune the a power increase or decrease gradient. Default value was 0.3%/s. I tried 0.1, 0.05, 1, 10, 100.

No improvements.

Meanwhile the installed solar power was increased to 6.4kWp in two equal strings. This does not help. The issue is still there.

It looks that Fronius changed something in Primo without taking in account that the changes will affect microgrid functionality.

To be continued...

Hi

I have systems running with the Fronius Primo in MG mode with no issues running the latetest firmware,etc. I own one runs in MG mod at home.

All with the Victron Multiplus2. 5kW units

Have you checked the grid impedance etc?

Regards

Rob D

NZ

@Rob Duthie which serial number range are your Primos? I have a new one with serial number 33334xxx and can not perform a rollback to a previous firmware version and the Primo currently runs with FW: fro33160. I also get the described flickering issue.

@popnic did you find a solution to your problem? I am all curious.

@Oliver

Thank you for reply.

I contact Fronius PV Support in English. (sorry for my English)

Since my last post, an another guy from PV Support contact me by mail again with "downdate" the firmware to 32071. They do not read previous emails from others from same team. I have more than 10 messages from them, one per week or one per two weeks. They really try to solve my "CAS"

My hope is that the firmware from Oct 2022 will solve the issue as one support team member who took the issue seriously write to me.

Meanwhile I use the MP2 5k connected to the grid, set ac input limit to 30W.

This setting avoid grid fed in (disabled in Cerbo) but I still have approx 1kW /day to pay. This is the price that I have to pay in addition because I have a new Fronius and I want to keep my system stable.

Anyway more restrictive rules are applied starting from May 2022 for prosumers in RO, EU. We have to put a counter from distribution operator to measure directly the PV aside of the necessary bidirectional counter.

PV energy surprising me every day.

@Rob Duthie

The stability issue take place when the grid is not connected.

I use 6mm2 copper conductors between Fronius and Victron. Now there are 12m between them.

All my important load are connected with 4mm2 and 2.5mm2 with max 12m length all copper and strong connections. My first idea was that the conductor resistance is the cause but I found that with 2m of conductors the behavior is the same.

I will ask an installer to measure the house grid impedance in MG mode if is possible.

Thank you for suggestion.

I have written to Fronius service a week ago, but so far did not get any answer. I found the following observation interesting: The flickering does not happen while in power state mode 560 (P(f) is ON). When in this state I can observe that in my case reactive power shows a negative value (e.g. "-1"). When flickering/pulsating happens this value is positive. In the advanced settings you might be able to set a reactive power (kind of introducing an offset)? Or a dirty workaround could even be to set the F limit frequency down to 50.0 Hz forcing the Fronius to work in Power State 560 always. As the Multiplus frequency is very stable at 50 Hz only a very tiny power reduction would happen. (I wonder if power reduction % is happening from inverter P nominal? Or from highest P daily?)

But honestly I wished Fronius would provide a solution soon. @popnic (your English is great, I perfectly understand all of what you are writing)

@Oliver

Fronius PV Support will contact you for sure.

They emailed me today and they offer two options to me:

Wait to the middle of October when a beta version of firmware will be available or

Replace the inverter with older hardware version one.

I chose to wait until October, see how it works.

In MG mode, normal mode, Victron set the frequency very close to 50Hz and Fronius will deliver all the power is possible from PV panels.

If Victron need to control the power form Fronius it increase the frequency. For my understanding this is roughly how frequency shift works.

In Profi menu you can set a lot of things but I think that you must know what you are doing. Maybe you can find a solution.

Good luck!

Any news about this case @popnic ?

I'm in the same case (fronius Primo in bus AC mode) and also experiencing flickering while disconnected from grid

@jeanmarie

Thank you for your interest in the subject.

Last message from Fronius PV Support - two weeks ago - was that they close my case. This was because I decide to wait the firmware version that fix that flickering issues for new hardware inverters promised at the middle of October this year.

The fix firmware is not available yet.

Best wishes,

Nic

Hi popnic,

I'm aslo from Romania and I'm using Victron Easyplus II in conbination with a Fronius Primo 3.5-1 on AC coupling. I had also notice the battery state changes from charging/discharging couple of times per second but only when the battery is almost full and bulk is finished. This was happend before to become prosumator and also now as a prosumator feeding the grid.

Do you have your system on VRM World? You coud see mine as RoMo - Cumpana.

Related to unstable microgrid with MP2 and Fronius Primo.

Fronius PV Support closed my case. I contact them again asking about the status of the firmware for new hardware version of Primo's. I will come back with updates if any.

@RoMo

What battery you use and what floating and absorption settings in charger section of Easyplus you have?

@RoMo

Charger settings are more or less ok.

In VRM I see that your system does not go into absorption nor in float so the charging cycle is not complete.

Maybe absorption time set to 0.25 and some settings in general settings as SOC when bulk finished set to 95-98.

A battery current and voltage widget added to VRM will show some additional clues...

Hi,

Victron has change something with their recent firmware updates, I have an AC/DC coupled system that used to function well, AC coupled side covered the daytime loads no problem while the DC coupled side just trickled away. Now all the loads are being covered by the DC coupled side and the Fronius is shutdown on 52.8Hz until the loads increase beyond the capacity of the DC coupled side to handle. The system has been biased towards the DC coupled side now which is defeating the whole point of the more efficient AC coupled system covering the loads directly in the daytime.

I have turned off my two 150/70 MPPT's to force the system to use the Primo now until Victron fix this issue.

Cheers

Hi All

Latest update loaded new firmware fro upd33350 for Primo 5kw, flickers real bad at any loads.

I have swapped to Fimer Uno inverter 5kw version as a test, no problems at all perfect. The issue is with Fronius inverter firware updates so changing over to Fimer now.

Is Fronius listening?

Change log below they say they fixed in this changlog note on pg161 for Primo MG50-60 modes.

Note: installed a Fimer UNO inverter 5kw no issues with microgrid mode go figure.

Regards

Rob D

NZ

Fronius SE_FW_Changelog_Fronius_Galvo_Symo_Primo_Eco_DE-EN (8).pdf

Thank you @Rob Duthie for reply. It is sad that new Fronius firmware updates are generating problems.

Fronius updated the firmware 333350 in my still experimental installation this morning at 4AM local hour.

The flickering effect is not more or less than before but it is there.

I am still waiting for firmware that works...

Fronius firmware 333350:

I had a chance look closer to the system while is cloudy and AC coupled PV inverter production is low and quasi equal to consumption approx (200-400W).

When it start to flicker, the voltage amplitude variation is less than before but still 217-242Vac and the pulsating hum form MP2 is also less. In same time the battery current is -7 to +8Adc half than it was before.

It is still bad but now I am more confident to let the system to do its job disconnected for the grid for a 1 day.

@jeanmarie , @Oliver , have you tried this 333350 firmware?

not yet.

I just checked for it, but seems my inverter doesn't find any newer firmware than the installed one (3.23.6-1)

Dear all,

Fronius PV support fix the problem for my experimental installation.

As I posted above, the latest firmware upd33350 did some improvements but was not enough so it was necessary to adjust parameters in Fronius Primo Profi Menu.

I think that Fronius will share the fix method to installers soon.

Thank you all for your support and patience.

Thank you for the feed back @popnic

Hope they will share it widely also for self installers

Hi All

Down graded to version fro 32070.upd so after after testing no flicker so far.

Used USB to upload the downgraded firmware.

Regards

Rob D

NZ

There seems to be an official answer from Fronius that doesn't involve firmware.

Sorry it is in french, must exist in english/german, should ask fronius :

Hi

Interesting Fronuis, they dont advise us down here in NZ about that one.

Regards

Rob D

NZ

Success!!!

The Installer gave me a Fronius (2years old) from his home installation to use to test in my installation. We installed that yesterday morning and we have now had two sunsets and one sunrise to test it thouroughly. The firmware version on it is 0.3.14.8. It works like a dream!

The next step is to get my inverter back to the Fronius distributer / agent to see if they can downgrade it from 0.3.28.0 to 0.3.14.8 or find a problem in the hardware.

Please see the answer from Fronius below. IT WORKS! Just note that in my case the flicker occured during sunset/sunrise, under low load and running off grid (Micro Grid) and even if the battery is not fully charged:

"The operation algorithm of the Fronius SnapInverter series (includes Fronius Primo) has been modified.

This modification affected the performance on off gird systems (Micro Grid systems).

The Victron Inverter/Charger increases the frequency to reduce the output power of the Fronius Primo.

In certain constellations, the modification causes a voltage flicker when the battery is fully charged and the consumption on site is very low.

Therefore, and special update file vic35069.upd has been developed to solve the flicker issue. On Fronius Solar.web this update file is shown as fro32071.upd.

This update file operates another algorithm which does not cause the voltage flickers.

Please do not perform any firmware update on the unit, otherwise the device will start to operate with the original algorithm and it will flicker again."

Regards

Spatula