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positron avatar image
positron asked

Faulty glitch on Multiplus II output

Hi,
I'm currently testing a new ESS installation based on Victron Mutiplus II 8 kVA + Cerbo GX + 6x Pylontech US2000C.
My PV installation works since 2019: Fronius Primo 6 kVA + 6700 Wc of LG solar pannels.
I would like to setup a classic AC coupling ESS (grid connected, with backup).
I'm based in France.
0-schema-general-v2.png


IP connectivity is OK. I have a VRM account and can see the different sub-systems.

MODBUS TCP connection with the Fronius is OK. I can see correct inverter output power.

BMS CAN connection with Pylontech master is OK. I can see SOC and battery state (idle/charging/discharging).

I used VRM + VE Configure to setup the ESS & battery parameters.


For the moment, I'm testing the system without grid:

- AC IN not connected

- AC OUT1 connected to main switch board of the house + Fronius Primo inverter

- SOC battery > 50%


When I start the system early in the morning, the Victron inverter starts discharging the battery and powers the house.

Everything is fine. My EM112 meter indicates correct parameters (230 V, 50.0 Hz...)


When the sun rises, the Fronius synchronizes and starts injection.

After a while, production is high enough and battery flow switches to idle, then charging...


After few minutes, the Victron Multiplus starts to do some strange noises / vibrations and I observe a lot of malfunctions in the house:

- LED bulbes blinking

- oven clock goes faster !

- UPS inverter (that protect routers) stops and trigs an alarm

- EM112 meter indicates crazy frequency of 60 or 80 Hz during few seconds, then back to 50.0 Hz...


I decided to use my digital oscilloscope to display the 50 Hz sinus provided by the Victron:

the result is big glitch on the output, matching the noisy events. (see pictures)


Oscilloscope captures: yellow = VRMS, blue = AC OUT current

- 3-pv-low-discharging-high.PNG : PV low, battery flow = discharging (high) --> VRMS & IRMS in phase (ok)

3-pv-low-discharging-high.png


- 4-pv-high-charging-high-ok.PNG : PV high, battery flow = charging --> VRMS & IRMS opposite phase (ok)

4-pv-high-charging-high-ok.png


- 5-pv-high-charging-high-glitch.PNG : PV high, battery flow = charging --> glitch


5-pv-high-charging-high-glitch.png


Should it be a configuration problem ? or a hardware issue ?
Maybe an incompatibility between the Multiplus II and the Fronius Primo ?
Can you suggest me some additionnal tests to do ? Or advices ?
I'm a bit disappointed...

I have updated the Victron firmware to last version last week (v497), but issue is still there...
Thanks a lot for your help

Multiplus-II
0-schema-general-v2.png (141.1 KiB)
3-pv-low-discharging-high.png (82.8 KiB)
4-pv-high-charging-high-ok.png (85.7 KiB)
5-pv-high-charging-high-glitch.png (89.1 KiB)
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4 Answers
jeanmarie avatar image
jeanmarie answered ·

Hi @Positron , I allow me to refresh your post.

I'm new in the Victron world and I'm on my way to get an ESS, basic one : multiplus 2, RS450, CerboGX, Fronius and LFP.

I'm following this trend as I already saw several threads on the same subject like those as most recent:

https://community.victronenergy.com/questions/134143/unstable-microgrid-multiplus-ii-fronius.html

https://community.victronenergy.com/questions/152748/victron-and-fronius-ac-couple-light-flicker.html

but also older ones

I encountered also some flickering issues with my installation but was unable to proceed with more test as I'm probably one of the unluckiest man on earth having one multiplus broken out of the box and my cerboGX in the affected list with power supply issues, this has blocked me from searching any further but I follow it up and I think there could be something there, unable to define what unfortunately

I would also be grateful if any specialist of the victron's world would join this subject to share their opinion

- there seems to be an issue with fronius firmware, ok

- is there anything known with, for example, wifi connected fronius and/or Cerbo instead of wired ones?

- anything else?


Any help in understanding this case would be warmly welcomed


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positron avatar image
positron answered ·

Hi,

It seems my mistake was on the Fronius side: I forgot to apply the MG50 profile !

I did a 3-hours test yesterday morning with this profile on the Fronius and the power generated by the Victron in micro-grid mode was clean. No flickering, no noise :-)

Now, I must test the case of full battery (frequency shift) and also the grid-connected mode...

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Oliver avatar image
Oliver answered ·

@Positron I have the same issue with a new Primo, serial number 33334xxx. The flickering happens when the Victron transits into "charge" mode and the smaller the charging current the more prominent the "flickering". Which serial number range is your Primo? Are you running the fro33160 firmware? Operation mode is MG50.


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positron avatar image
positron answered ·

I have a Fronius Primo 6.0-1 S/N = 29362xxx (march 2019).

I don't know the firmware version... How can I get it ? I never updated the inverter...

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