ESS and DESS Issues and Grid Export

Q&A and troubleshooting DESS
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1

Hi,
I live in Australia and purchased the MultiPlus-II 48/5000/70-48 Inverter/Charger, latest model supporting Australia ESS Grid connect

  • Running firmware 552
  • BYD Premium LV Flex 5.0 battery 5kW x4 firmware 1.16
  • BYD BMU latest firmware as of last weekend
  • Cerbo GX latest firmware 3.54
  • Fronius Primo 5.0 firmware 0.3.30.2 and Data manager 3.32.1-2

The fronius is I believe connected to the AC Out of the Victron
Victron has grid code details as below.
Australia A: AS/NZS 4777.2:2020 stand alone app. M (no N-bypass)
AC input 1 Above selected gridcode plus LOM B (compliant)
TAB: AS/NZS4777.2:2020 Australia A (Stand alone appendix M)

I am not 100% sure but I believe that Stand alone appendix M does allow for feed back to the grid? This is what was set by the Solar company when adding the system to the grid.

My system setup above supports ESS and grid export according to all the literature, however setting the grid setpoint to negative does nothing at all.
In fact when I see from the VRM portal it attempt to export to the grid it hard reboots my Fronius and once completely dropped the grid with a grid failure.

Switching from inverter mode to on within the Multiplus drops the PV for about 30 seconds or more. I suspect they had missed some configuration on the Fronius for frequency shifting?

Yesterday with Multiplus on and in DESS mode self consumption (manual rough pricing entered), the PV was throttled or dropped off for large parts of day. I have no idea why this would be doing this it should be powering my house loads, not using the battery and the grid?

I tested automatic dynmaic ESS again yesterday, and even though on the VRM graphs it showed in the energy tab light blue forecasted battery to the grid, it did nothing at all.

I have all this system in home assistant as well using the Victron integration v0.5.0.

As an end state, once I can get the inverter to even export.
I have an IAM Meter 3 phase and single phase power monitor, well before I purchased this victron and batteries, I was hoping to use the data from this in home assistant and my localvolts power plan wholesale pricing data to control all of this based on 5 minute pricing data and forecasts. Since there is no support outside of Europe for this automatic feed to dynamic pricing.

Does this sound possible, and does there need to be changes to my system to get this all working? so I can get this company back out to fix it up and get it working as I was expecting?
Does my configuration require a Victron specific grid meter to get the grid export working?

2

Feedback is best set up using the ESS menu.

Confirm you are programmed according to the BYD page?
And you have this done on the fronius?

Switch off DESS for now and get the ess feed in working first. Then add the next levels of complexity with dess and home assistant.
With DESS it is important to set the battery costs up properly as well.

3

Hi,

Thank you for the information and pointers.
I believe all the settings were done as per the BYD to Victron page, I myself did them initially. Then had a solar company come out and complete the setup and join to the grid. So I will now need to go through all of this again and double check to be sure.

I switched off DESS as suggested as it is not very useful outside of Europe anyway due to no dynamic pricing. For what its worth with DESS the battery costs were setup as per the formula, I did this from a Victron ESS youtube video.

I was reading this Fronius link earlier today, I had assumed the solar installer did this when they installed the Fronius and configured ESS on the grid, as that was what they were commissioned to do. After reading this and the behaviour I do not believe they did. And I enabled Modbus the other day on the inverter in an attempt to add some registers into home assistant missing from the standard integration for monitoring.

Is there any additional logging (audit) that can be enabled on this that could be helpful?

I will report back

4

No it isn’t
There is a feature under scheduled charge to look at though. You can set priorities for solar or battery or grid use and set different SOCs.

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5

You should check with your Grid-Provider, if you are allowed to feedin AND if the Grid-Meter you have is suitable for that.

There are meters that have a mechanism to detect energy beeing feedback, and then cut-off the grid. (Tamper-protection on meters that otherwise would run backwards)

You mean, when the multiplus restores Grid Connection?

No, then this behaviour is intended and required: The multiplus will drive inverters connected on ACOUT into a fault state by first raising the ACOUT Frequency, so they don’t ramp up their power, while the multiplus is resyncing with the grid - where it would need to go back to normal frequency, first.

Otherwise - if your battery is fully charged - the PV Power would have no where to go and heavily overload the battery during the reconnect process.

6

Sorry I shouldn’t have generalised that comment, it would be fine for anyone who isn’t on a dynamic pricing.
I am on a dynamic wholesale power plan that changes every 5 minutes, so is not useful to me because one day from another at 6pm could be exporting 20c/kWh the next day $20/kWh. That is how volatile the Australian market can be with the generators and demand. We have a body called AEMO who set a “fair price” then the power company puts their cost at that 5 minute window to supply.

I can also confirm that the installer did not set any of those Fronius settings, thank you for pointing that out, I have now set these.

I now need to go through the Vitron BYD guide and verify all the settings

7

Yes I can export 5kWh max on single phase, this was working during the day prior for solar export. I will double check it there is a time window for this, although I do not believe this is the issue as I can’t export battery when I would have been previously with m old grid connected Growatt inverter

Thank you for the information on the PV, this part had not been fully setup by the installer, I have now completed these settings. Yes I understand about the battery charge state and this dropping off the PV (rebooting the fronius), but it wasn’t prior supplying house loads either?

8

If you could give me your vrm site id (the numeric one in the vrm url) I could look up if this may be DESS related, and if:

  • The system did not behave as planned
  • Or if the plan just did not match your expectation.

IIRC, Currently DESS supports hourly changing prices, but this is suspect to be changed. So, it may just be the Case that Dess assumes an average price for a certain hour, which then isn’t well suitable for the minutes above or bellow average.

9

Hi Dognose
ID is 712134.
At this point in time I am just trying to get my Victron to export any energy to the grid. Once I have ESS working to export to the grid that is a huge step forward. I have send a support request through to my power provider to ask if they have any restrictions on the time(s) I can export.

I still suspect it is the grid codes used by the solar company to join the grid blocking the export, but they are not being forthcoming in helping with this or answering questions.

The plans looked fine with basic information that I put in the DESS config, at first the times were in some other zone, as the logic was flipped, I rechecked the location and restarted the system, and it can right.

My final end goal once I can export is to run ESS with external control and control the charge and send to the grid via home assistant. The switching wouldn’t be every five minutes, but if there happens to be a price spike to ramp up export during that point and bring it back down once the price come back again. Which would generally be from 5pm to 9pm in Australia and again in the morning 5am to 8am where the export price would generally be above in battery price per kWh

10

I’m not an expert on Grid-Codes, but I can see that you set a negative setpoint of -1812 today, which the system didn’t do.

So, “something” inside your system configuration is telling the inverters to not feedin.

I’m noting, that your VRM Portal is showing no value for “Grid” and also your system reports “AC Input 1 connected: Not connected” - Can you check the LEDs on the multi? Seems like he is either NOT having a grid connected or rejecting that grid for whatever reason.

This may be related to a (wrong) Gridcode, when the actual parameters of the grid (voltage / frequency and many more) drop out of the grid-code parameters, then the multi will switch to off-grid mode.

Grid is “there” from time to time, but most the time not:

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So, your Issues of the system not feeding in is a consequence of what seems to be an unstable grid. Now you would need to figure out, if that is related to the grid code, caused by a faulty physical connection on your side, or eventually caused by your grid-provider / grid meter.

11

Thank you so much for taking a look into this.
At the time you most likely looked into this I would have switched the inverter to inverter so no grid, to stabablise the PV to charge the batteries and supply the loads.

In addition due to the dodgy way that Australia charges for grid usage for ON DEMAND from 4pm to 9pm I was switching to inverter only mode because I do not want to use power from the grid. I will explain it below, it should be illegal.
Every month you are charged for the highest day usage of power for that month, it is then applied to every day, so you are effectively paying for power that you didn’t use. I will provide a scenario.
A person is away for the almost all the month of February, say they arrive on the 28th and use power during on demand, when their bill arrives they will be charged that demand usage on the 28th and it will be applied for every single day of that month.

So therefore until I can get the batteries supplying the grid and not consuming during this period with ESS I have an automation that switches the system to inverter. Also when the grid price spikes too crazy I switch to inverter, because I can’t feed to the grid during these times at the moment to get paid for export rather than charged lots more to consume.

In terms on the grid setpoint that was me attempting to test if the system was going to attempt to export, after making a number of changes that the solar company did not do as part of the ESS commissioning.

I will get a sparky to run some tests and checks the cables etc that ultimately connect to the grid, because our grid is normally extremely reliable.

thank you again for looking into this.

12

That is really a crazy pricing policy.

Well, ofc, when you switch to inverter only, the system won’t feedin. But assume, you had it connected again when testing this.

So, would need to check what the grid values were during your testing attempt. Eventually it was supposed to reconnect to the grid, but didn’t do it.

13

@danwnz,
I also have a grid connected MP2 victron setup, connected to Home assistant. I don’t use the integration at all, rather map all the ModbusTCP addresses via yaml. There is a full list of registers available on the victron professional portal which you can sign up to access.

My HA does full control of the ESS setpoints based on wholesale pricing and battery SoC etc, so it’s all doable, for when you know what you are allowed to do.
I am not using Annex M on my MP2’s as i havn’t upgraded them to that yet.
I use my home assistant functions (via Node Red) to buy or sell automatically.
Hopefully you get to enjoy the same very soon!