V3.70-beta single unit on three phase system peak shaving question

It appears that with the latest FW, the peak shaving does not work properly with a three phase system. I would expect it to limit per phase, in order to avoid burning fuses. It seems to limit total L1+L2+L3 amps, which is not as useful.

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@jkoljo Can you tell me what the last firmware was where this still worked correctly? I ask because there was only one small change in ~34, which only applies if you have “Self consumption from battery” set to “Only critical loads”. Can you give me more information, do you have this setting set? Can you give a date and time when the issue was observed?

Hi Izak, thank you for your reply. Unfortunately our electricity use profile has just recently changed because we bought an EV and the heating season is starting. While I have had peak shaving configured since summer and it has worked great to limit blowing one main fuse with L1 MP2 + L1 EV charging, I suppose I might not have had significant load on other phases to reveal the issue (especially during summer time when no heating is needed).

Sorry for the non answer. I will gladly test any potential fixes.

@jkoljo , I did look at your site yesterday (you only have one linked to this email address), and it looks like it has a single Multi on L1, in a three phase system. There are some known issues, not easy to solve, with doing peak shaving in this kind of setup, specifically because the system also tries to feed energy back to cancel loads on the other phases. It will be fixed in future, but in the mean time, this is at least not a new problem. It has been around for as long as peak shaving has been around.

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@iburger Because the other topic is closed ( Venus OS v3.70~61 available for public testing - #289 by kr0815 ) and therefor I could not reply to your suggestion, I do it in this topic as it’s also relevant for @jkoljo :slight_smile:

With the latest 3.70 beta half of the issue is indeed fixed! Very happy with that. You can see in the prints below that max limits on L1 are now respected. First picture is with ESS Peak Shaving import limit set to 5A and the next to 10A. Both are working fine now.

For the ESS Peak Shaving export limit set to 5A and setting a grid setpoint of -4000W to get the export going the issue is still present. It sums up all the fases instead of looking to L1 only. (2.5A + - 5.3A + -2A = -4.8A total)

Maybe the developers can check what they changed in Peakshaving and apply the same sort of fix to the export limits. Anything I can provide to help?

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