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wernerhoelzl avatar image
wernerhoelzl asked

Venus OS v3.30 – Peak shaving limit export current not working

Hi,

I'Ve installed the Venus version 3.30 and also updated the ESS assistant to the recent version. Unfortunately when activating peak shaving export limit it does not work. It will throttle my Fronius 10kW inverter permanently.

I've an old Solutronic inverter (4.5kW) connected to AC in which can't be throttled. On AC out sits the Fronius inverter connected via Modbus. Additionally I've an MPPT connect on the DC side and a Pylontech battery. The ESS consists of 3 Multiplus 5000.

I've activated both peak shaving limits with 35A. Today in the morning the total power was around 2 to 3kW and everything was used on AC loads and charing the battery. There were no charging limits and the system was far away from full power. The grid point is 0W and there was no load. I really was wondering when I saw, that the Fronius inverter was throttles to around 1/4 of the possible power. But why? No load on the grid and the battery was far away from the charing limits. After deactivating export current limit it was working again with full power. I could reproduce it by activating it again. The system feed in setting was deactivated, but feed in limiting showed active every time I've activated the export current limit.

Do I miss anything? I believe that there is a bug in the new version.

Regards,

Werner

ESS
4 comments
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Alexandra avatar image Alexandra ♦ commented ·
A pylontec battery?
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wernerhoelzl avatar image wernerhoelzl Alexandra ♦ commented ·

Yes, it is a Pylontech battery

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Alexandra avatar image Alexandra ♦ wernerhoelzl commented ·

More specifically one single pylontec battery?

I am wondering how far from charge limits the system actually is?

Please clarify your description.

And did you update all the MP firmware as well? Or just the assistant?

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wernerhoelzl avatar image wernerhoelzl Alexandra ♦ commented ·

4x US5000, SoC around 30%, charing limit set to 300 A, grid was around 0 W. All firmwares are up to date.

I've two screenshots from Grafana:

1st shows load on grid and battery charing:

bildschirmfoto-2024-03-27-um-195109.png

2nd shows inverters and MPPT:

bildschirmfoto-2024-03-27-um-195011.png

The yellow line is the Fronius, green the Solutronic, and blue the MPPT. Before 9:20 you can see, that the yellow line sometimes is dropping while the green and blue rise or at least stay constant. Total production is still very low, since it is early in the morning. At 9:20 I turned the Fronius off because I thought there is a malfunction. After restarting it, it was not better. After I turned off peak shaving at 9:45 it worked as expected.

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bildschirmfoto-2024-03-27-um-195011.png (361.3 KiB)
bildschirmfoto-2024-03-27-um-195109.png (290.3 KiB)
2 Answers
nickdb avatar image
nickdb answered ·

Do you have a grid meter?

It won’t work without one.

It is also not intended for use when you are cascading inverters, something that isn’t supported anyway.

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wernerhoelzl avatar image
wernerhoelzl answered ·

Of course I have a grid meter. This is my setup. The left inverter can't be controlled, the right is the Fronius, connected via Modbus. To be honest, I don't understand why this should not be supported.


bildschirmfoto-2024-03-27-um-181430.png



bildschirmfoto-2024-03-27-um-181430.png (238.4 KiB)
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