Setup: Venus OS 3.66, Multiplus 5k with both Victron MPPT DC solar and SMA Sunnyboy AC coupled solar (on ACin).
I’ve setup Max feed-in limit to 2000W. I noticed that when battery is full and excess solar is being fed in, the AC solar is throttled down when there is more than 2000W total solar available, i.e. system decides to use DC solar via MPPT first before feeding in AC solar. While I was still running in ESS mode I had dc-solar feed in disabled. But DESS ignores this settings.
To me that’s not very logical, we have AC solar power available for feed-in but instead we use DC solar which has to be converted to 230V by the multi before feed in.
When PV needs to be throttled, the System will - if DCPV Feedin is allowed - always throttle ACPV, first, as the DC MPPTs are easier to control to cover consumption precisely.
AC Inverters just don’t “show” their conversion losses, as they only report their AC-Outputpower. They have the same conversion from DC to AC as a MPPT / Multiplus pair would do. Just invisible to the system.
Another technical reason is, that in case of a grid loss, it is more stable to have DCPV already producing than eventually losing ACPV Inverters and have to ramp up throttled DCPV.
Too bad though that DESS ignores DC-feed-in setting so I can’t control this. The reason I would like to feed in AC power iso DC power is … noise. My SMA inverter is completely silent, the multiplus running all the time creates a lot of noise in my garage.
Just disabled DESS so ESS is taking over, with dc feed in disabled, acpv is now fed in But I can only do that when feedin prices are not negative, so need DESS to direct this.
But I can only do that when feedin prices are not negative, so need DESS to direct this.