question

Lawrence avatar image

Frequency Shift staying high all Night

Hi, I have an installation with an 8kw Quattro and a 3kw Fronius AC coupled. 30kw of BYD Premium LVL. Also has 5kw solar on MPPT.

The Quattro shifts the frequency as expected when the battery is full, but doesn't drop it back to 50htz when the sun goes down. In some cases it drops it back at 2 or 3 am, and in the case of the attached PDF, it held it up until 6.50am the next day. Note the battery is down to 83%SOC. Freq graphs.pdf

frequency
freq-graphs.pdf (360.2 KiB)
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1 Answer
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

Hi @Lawrence,

This behaviour is described here - https://www.victronenergy.com/live/assistants:pv-inverter-support#q1_-_the_system_is_locked_to_53_hz_and_does_not_resume

Please check that the Multi is correctly configured for lithium batteries and the absorption/float voltage.

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Hi @Guy Stewart (Victron Community Manager)

Its not locking out at 53hz, its sitting at 52.72.

And i did read that and check all my settings. VE config settings.pdf

When the sun goes down with only 200w load the battery voltage is sitting at 53.1 on both the Battery monitor (BYD via CAN) and the VE Bus

I have a 3kw diversion load on AC2 out running off assistants. Ive noticed that once the Quattro lifts the frequency, it does it in one jump from 50 to 52.7, once up, it stays up the rest of the day, even with the 3kw diversion on and only 1500w coming from the MPPT

I might have to pass this one up to the chain, but before I can. The first thing they will ask is can you please confirm firmware version on the Quattros and the Assistant (in VE.Configure) to make sure that they are current latest release?

Lawrence avatar image Lawrence Guy Stewart (Victron Community Manager) ♦♦ ·

Chip number in the Quattro is 2655430 and i updated it to 433 b4 it was installed. Not sure how to find if the assistants are up to date, but every time i open VE Configure and it asks to up date i always do.

The CCGX and the MPPT are both up to date as well. The BYD is the only thing that is not up to date as it was a last minute substitute. The FredomWon that we sold with the job was stuck at the port in South Africa. As we never intended to use the BYD, we don't have a spare ethernet port, although if needed i can put a long range wifi on the CCGX and use its internet connection for the BYD

Alright, Updating the firmware on the Quattro is the first thing that needs to be done. The current version is 476.

There are several ways to do it, you must back up all settings on Quattro first, as they will be lost.

Once the settings are backed up (!), it is easiest to do the firmware update in VictronConnect.

Alternatively, you can use now depreciated method in VE.Flash (after getting the specific firmware file from VicPro).

Lawrence avatar image Lawrence Guy Stewart (Victron Community Manager) ♦♦ ·

have updated it to 476 and also updated the byd to the latest. will monitor over the weekend.

Hi @Lawrence

While the tools are out, can you please confirm the grid code on the Fronius is set to MG50.

Another possible cause is that if the Fronius is not responding as expected to the ramping of the frequency shifting (which requires this special MG50 code), then the Inverter Charger will default to an all On (50hz) / all OFF (~53 hz) behaviour.

How to do this now the unit is commissioned is shown here:

https://youtu.be/Fm6FdpClLBo?t=1458

Lawrence avatar image Lawrence Guy Stewart (Victron Community Manager) ♦♦ ·

yes definetly set to mgfifty (the five on my keyboard jut died)

The hz dosent ramp, or if it does its within the 1 minute window that VRM captures. I note the BYD charge current limit goes from 432a to 0a in one jump, which is when the Victron bumps the hz up.

Lawrence avatar image Lawrence Guy Stewart (Victron Community Manager) ♦♦ ·

So after everything updated and checked we had good weather yesterday and the battery was full at 12.50ish. The frequency ramped up over about 10 minutes. Last solar from the MPPT was just after 7pm but the frequency stayed up until 11pm with the battery SOC at 86% at that time. Also note that due to the diversion, the SOC dropped to 98% at 2.18 pm, which is when the BYD increased its charge limit. Freq Shift Issue.pdf

freq-shift-issue.pdf (650.4 KiB)

Thanks for reporting back @Lawrence, we've got some ideas and are looking into a fix.

julzb avatar image julzb Guy Stewart (Victron Community Manager) ♦♦ ·

Hello guys. @Lawrence @Guy Stewart (Victron Community Manager) Any update on this issue. It seems like I have the same problem which just developed on a system of mine with a 10kva Quattro and 6kw Primo.

The frequency was upped when the batteries were full at 100% but it never shifted back down even after the battery voltage dropped to below the re-bulk state.

This just happened 2 days ago.

Not as yet, my site is still holding the frequency up sometimes as late as 2am by which time the battery is under 90% SOC.

No news or updates yet, not forgotten though, I have an open internal support ticket.

Good to hear from anyone else in the same situation - more data will help the engineers isolate the exactly cause and solution (for the most people).

julzb avatar image julzb Guy Stewart (Victron Community Manager) ♦♦ ·

Thanks for the updates @Lawrence @Guy Stewart (Victron Community Manager). I noticed something weird with mine last night. The frequency shifted from 50hz to 52.7hz in the middle of the night (about 9 pm, which means it was discharging as it happened. As of this morning, it is still stuck at 52.7hz. The charge controller kicked in with no issues but the Fronius is yet to resume because the Victron has not reduced its output frequency.

Lawrence avatar image Lawrence Guy Stewart (Victron Community Manager) ♦♦ ·

Hi Guy, So i compared the settings in a similar installation i have that uses a Freedomwon battery and is working fine. In that installation the Absorption voltage in VE confige charger tab is the same as the absorption in the MPPT. In Victron's Instrustions for setting up BYD it has the VE Config absorption at 55.2v but the MPPT is set to 56.5.

So i changed the absorption in VE config to match the MPPT setting today and watched it like a hawk as the battery approached 100%. For the first time, it kept the AC solar going to match the load, and regulated the MPPT and has kept the battery at its float voltage. Previously, when the battery hit 100%, the HZ jumped to 52.7 and the Fronius shut down for the day.

Can you see any problem with leaving this setting match to the MPPT? Is it perhaps an error in the setup guide as i note the Freedomwon setup guide has both setting the same.

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Lawrence avatar image Lawrence Guy Stewart (Victron Community Manager) ♦♦ ·

Hi Guy, Any updates on this? Up until now this issue hasn't affected performance of the system as the frequency has always returned to 50 hz by the time the sun comes up the next day. I've noticed three times in the last couple of weeks that the frequency has stayed high into the next day so it now is affecting performance as the battery never made it back to 100% the first day it happened.

We ran a few tests to see if we could identify where the issues was. Firstly we turned the Canbus off, just to see if the battery was holding the frequency high, no change

We then reduced the MPPT amps to 5 as there is a large DC component, no change there either.

We also reduced the PV size in the PV Inverter Assistant, that didn't change it either.

My distributor (Rod from Taspac) has suggested replacing the Quarto but i don't want to go down that track unless we are certain it will fix the issue.

Frequency Shift 3.pdf