question

Martin Gasthuber avatar image
Martin Gasthuber asked

Manage and control power in ESS config - incl. PV and battery as source and/or sink

Hi,


I'd like to pick two topics being discussed previously in several theads but never gotten proper conclusions or mitigations. Base is an 3-Phase ESS config, 30kWh BYD LVL battery, historic PV on AC-IN (with active payment on feed in), PV and CHP on AC-OUT1 and or course all consumers (rest of the house) on that. Meeting all criteria (1:1 rule, batt capacity, Fronius Inverter, ... all on latest greatest firmware levels) and the not really up-to-date documentation with real SW running i have to ask here some questions and made simple proposal (RFE in other words).

The 'Zero feed in' - Fronius PV power regulation while AC-IN is active - is by far too pessimistic. In a system with a trustworthy battery system and their calculated and published limits (SOV, max charge current, ...) i would consider the current behaviour 'need polishing++'. While the battery (in my case) shows >480A charge limit even as 99% SOC, this should be the main parameter the 'zero feed-in' mechanism is looking at. The mechanism today is bound mainly to the AC consumption and not the DC current capabilities.

Several (public) papers and other threads here have mentioned the 'best practices for LIFEPO SOC levels' to maximize cycles and lifetime. If not impleneted in the core SW (venus+Multi) it should be possible to achieve decent results allowing to set (i.e. via Modbus) a target SOC (obviously lower than 100% in summer times) the system should apprroach. In order not not dig into the inner ESS control loop (ESS mode 3 and further), it would be nice to allow these types of 'hints' being generated ouside of venus (i.e. external control scheduling - i.e. using solcast to process forcast data and react on that). To ensure proper operation in all kind of error consitions, these 'hints' needs to be updated on a regular base (i.e. in the order of hours) and if no update comes in time, go back to the default classical limits.

Did i miss other existing features solving that by a different way ? i'm happy to know ;-)

best regards,

Martin

ESSAC PV CouplingBYD
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

0 Answers