Peak Shaving Problems

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kevstone122 asked Nov 21, '23

Peak Shaving Problems

I want to open an thread with the Peak shaving problems.

Maybe i am wrong about this problem?

Maybe someone else knows additional problems?

I have Cerbo Version 3.10 / ESS System 3-Phase.

If Peak shaving is "always on", the battery get more and more empty and then suddenly it will recharge the battery full from grid and not slowly. What has this to do with peak shaving if we create a big peak for charging afterwards?
If we adjust the ESS to "keep batteries charged", i cannot adjust the "peak shave mode". It will be set to "always on" AND then a really dangerous thing happen. If the DVCC is at 0A, the system cannot reach this setpoint. I have always +25A until the battery get overcharged and BMS will switch off. DVCC must always control the limits as first priority and should not take care in this case about peak shaving!

What do you think?

Is there any option to force the peak shaving to OFF?

Thanks for every information!

ESS DVCC peak

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Modifications Space

Node Red Space

Answer 1 · 2023-11-22T04:58:17Z

Alexandra answered · Nov 22, 2023 at 04:58 AM

You can force a more traditional peak shave by lowering your input current limit.

And you can set the peak shaving to only above min SOC in case of grid faliure.

And if you set such weird combinations the system it is going to exhibit strange behaviours. What was the idea behind the DVCC 0 set point? To stop charging?

Is your system programmed one each component with all the correct voltages for charging? Is your battery can managed? Is it an officially supported BMS?

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kevstone122 commented · Nov 22, 2023 at 08:00 PM

Hello Alex, Thanks for your answer!

lowering input current: Good idea actually, but if there is a huge load in the house, i don't want to limit this. Like you said, yes i just control the batterie with the DVCC current. I am not a friend to charge a Lithium battery just with voltage which you measure just outside.
The charging current will be limited with more then the outside voltage. About this outside voltage i don't care. I control the charging current over each cell voltage, difference voltage from the highest to the lowest cell, 6x temperature, soc level. So the Batterie can be much better controlled then with voltage. The charging current was really bad with voltage limitation and settings like absorber and float voltage over some time ranges are total useless. During winter i want to collect every sun-power as possible and won't starting grid feed in because voltage exceeded. If each cell i in the level, keep going on. So in my case the DVCC level get set from NodeRed with some functions.
I had never a problem about this. Charging up to 460A is working without any troubles since 2 years. BMS is extra in case like some shi** happen, then this will switch off like now with peak shaving. If victron doesn't follow the DVCC adjustment.

Back to the topic: The DVCC adjustment is here to control the current to the battery. If i set this to 0A it is always working (DC coupled charging need to be off). But if peak shaving is on the troubles are starting. Why i get forced to use it with the ESS mode "keep batteries charged". If i use normal ESS mode without Battery Life i can also choose "only above SOC".

And this is coming just with the update and suddenly the system doesn't work...

Can i force it in NodeRed to OFF. ALWAYS OFF Don't need it, Don't want it :)

BMS is Chargery with normal serial communication. All values are inside NodeRed. But this has in my opinion nothing to do. DVCC is here to control the battery current and now it get ignored...

Best regards
Kevin

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Answer 2 · 2023-12-16T19:48:49Z

kevstone122 answered · Dec 16, 2023 at 07:48 PM

Also with 3.13 it will not work. If i adjust 0A at DVCC charging current, still there is more then 20A...How can i open a Bug-Ticket at Victron?

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