question

seriusrod avatar image

ESS fails after a blackout

My system is composed by:

  1. 4.5 kWp solar array
  2. 1x 150/85 VE.Can mppt
  3. 1x MultiplusII 48/5k (single-phase)
  4. 1x GX Venus
  5. 1x smartShunt
  6. 11kWh 48v lithium battery
  7. External BMS, not connected to the system.
  8. Modbus meter connected to the GX and measuring grid

ESS & Multiplus Configured for:

  • Mode: Optimized w/o BatteryLife
  • External meter on Ac-In, just after the grid connection.
  • House loads on ac-out1, ac-out2 not connected to anything
  • Sporadic car charger on Ac-In (between meter and multi) / Ac-In setup as in use.
  • DVCC disabled.
  • Charge and Inverter limits disabled.
  • Feed-in disabled.
  • Grid setpoint 20w
  • Minimum SOC 30%
  • Battery voltages: Absorption 55,3v / Float 55v / Low shutdown 44,8v
  • Battery capacity 200Ah
  • Lithium system with other BMS (not connected)
  • Mppt & smartShunt configured with the same parameters.

In my zone it's normal for a period of the year to suffer grid blackouts. They can be from minutes to several hours, but I have no problem with quality.

When a blackout happens, the system behaves correctly.
When the grid returns, the multi charger starts itself, sometimes faster than others, but the loads on ac-out1 only receive energy from the grid. The mppt continues to serve energy from the panels, but only for the battery charge and all loads are supplied from the grid.
Also, it seems to be a problem with energy flow management as it's intermittently reporting big loads on ac-in, when I don't have anything connected to it.

The problem persists (waited hours) until the Multiplus is hardware-restarted by completely turning it off, waiting and then turning on again (switch at the bottom)

This is a big problem for me, as I mention there will be blackouts. I like the possibilities of ESS but If I can't solve this, I'll be forced to migrate it to virtual switch, and that's not optimal for the size of my system.

Also I noticed that while the blackout, the charging phase always show "Inverting" and the Victron nodes, mqtt, etc, all output alike. I would like to know where I can report this as an issue, like in some git project. Not reporting the battery charging phase does disallow making automations based on this data. It's valuable for diverters, for example, as the setpoint should be different on every stage.

With the pass of days I'm seeing that the changes/problems are more extense. I'm concerned about two of them:

Before, it charged the battery until absorption at full throttle. Now it charges at low power (@1500w max.) even when more solar yield is available, as it is applying some kind of manager that wants to extend the charge to the full day. That's not good because in my region the available sun is scarce, and I have to get the battery full as soon as possible.

Then there is a strange behaving after the absorption phase. I have Float 0,3v lower than absorption. Before when absorption ended it gently left the battery alone (power between 0 and 20w, and slowly with the normal use it reached float. Now it applies a constant -200w load that is steady for more than 1 hour. I don't know if that's a false measurement (possibly), but the effect is that no other diverting appliances can be used in float, as it always reports negative power to the battery, while loads are successfully supplied by solar.

Thanks!

Multiplus-IIESS
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1 Answer
Alexandra avatar image
Alexandra answered ·

@seriusrod

Your system firmware needs to be updated.

What version is the inverter on?

Mppts, gx device? Looks like the venus needs an update.

Usually see issues like this when only part of the system is up-to-date and others not.

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Dear @Alexandra,

My inverter is at version 487, that is the latest.
Also the mppt is at the latest: v3.07

And the GX device is running v2.80~11.
I think still there's one fresh version for the Venus Os, but I don't think that would be a question to be on the edge, isn't it?

Alexandra avatar image Alexandra seriusrod ·
@seriusrod

I guess that is not the issue then.

So if you have w/out battery life is there a soc set point you have that the multi charges to then? Usually w/ pit batt life it doesn't bother charging from grid.

The other question i have is what is number 6 on your list? Solar but no charge controller? A pv inverter that has no comms with the gx?

The multiplus 2 is it two multiplus (parellel or split phase?) or one MP2

What mods have been done to the system? You have mentioned reporting something on git hub?

seriusrod avatar image seriusrod Alexandra ·

Hi Alexandra. I've completed my question with detailed info.

As for your questions:

I've never seen my system charging from the grid.
My solar equipment is a "smartsolar mppt 150/85-tr ve.can" to be more precise. And I don't have any Pv inverter.
Single phase, only one MP2
No mods have been done to the system. I mentioned github as I was asking for a way to report issues in firmware versions. I thought it could exist a git repo only for reporting.

With the pass of days I'm seeing that the changes/problems are more extense. I'm concerned about two of them:

Before, it charged the battery until absorption at full throttle. Now it charges at low power (@1500w max.) even when more solar yield is available, as it is applying some kind of manager that wants to extend the charge to the full day. That's not good because in my region the available sun is scarce, and I have to get the battery full as soon as possible.

Then there is a strange behaving after the absorption phase. I have Float 0,3v lower than absorption. Before when absorption ended it gently left the battery alone (power between 0 and 20w, and slowly with the normal use it reached float. Now it applies a constant -200w charge that is steady for more than 1 hour. I don't know if that's a false measurement (possibly), but the effect is that no other diverting appliances can be used in float, as it always reports negative power to the battery, while loads are successfully supplied by solar.

Alexandra avatar image Alexandra seriusrod ·
So all was working then components were updated, now the behaviour is different?

What energy meter do you have and I assume it is hooked up to the gx? Has anything changed with that? If you (areable to or allowed to) disable or remove it from the gx does the ess behaviour change?

Hi Alessandra,

After upgrading the Venus device, There isn't any difference. A picture from now, almost in real time. Is getting energy from the grid although there's plenty of sunpower. Production should be +3800w. There was a small blackout during the night. No voltage or frequency irregularities where registered.

20210923-132929-from-grid-without-necessity.png

I haven't changed anything, still have the modbus meter connected at the grid entrance and correctly setup in the GX. Remote console shows it's data in devices and it's configured as grid meter. I've tried disabling the loads on ac-in and use the internal meter of the multiplusII but that wasn't an improvement.

Edit: The values shown in the picture are steady. They are not a peak or something.
From time to time it gets stable and works as expected. That's why I know the PV system capabilities.

20210923-134009-after-a-moment.png

But after a while, it loses itself and goes crazy with grid management again.

I still dont understand how your system is setup.

1. Is your grid meter metering before the multiplus? If it is why is it showing as a critical load?

2. Is there anything connected to the AC out at all? it is always reading zero except where there is confusion in the first video.

3. Is the ess assistant actually programmed on the victron? Are there options in the menu of the gx under ess?

If you lower your input current limit does the solar provide nore to the loads?

I'll explain:

1. The grid meter is directly connected to the grid (after a protections module, but nothing more). The MultiplusII receives the grid after the meter.
2. The entire house is tied to Ac-Out1. So all home loads are on the output of the multi.
Except the EV (my car) charger that is connected to Ac-In, between the meter and the Multi. But I don't really use my car charger because there a pay-free nearby.

3. Yes, the ESS assistant is configured in the Multiplus and the ESS options appear in the Remote Console.

vec3-mp2-10.png

gx-3.png

vec3-mp2-10.png (25.4 KiB)
gx-3.png (62.5 KiB)