Expected behavior: power assist only kicks in when AC current limit is reached.
Example:
AC current limit is set to 10A;
AC voltage is 230V;
As long as power consumption is below 2300W power assist never kicks in.
Yes, I understand that some power consumption peaks might be significantly higher than average power consumption figures.
Actual behavior (wrong): power assist kicks in constantly while consumption is not even near the AC input current limit.
Example:
I have some load which on paper can consume up to 2000W in total which it never does according to 3 different power meters that I tried (including Quattro-II itself);
According to VRM the AC input power never exceeded 700W;
According to VRM the AC output power never exceeded 900W;
According to VRM the AC input current never exceeded 8.5A;
According to VRM the AC input voltage never dropped below 206V (at that moment the current was 7.8A).
And here’s the problem:
Power assist keeps kicking in constantly when I set AC input current limit to 10A, 13A, 16A, 25A and even 32A!
When I set AC input current limit to an insane 63 Amps it finally stops doing that!
I believe all loads have switching power supplies , you might have interference between the mp and the loads. To solve this you’d need a massive filter, or you could try a 500-1000 w heater as ballast for the mp.
There’s definitely something wrong with the inverter firmware.
Not the load, not the AC input sinewave or voltage or anything else.
I now confirmed my theory for several times.
The power assist starts to kick in periodically then more and more often up until it kicks in once every few seconds or so. I can only stop it from doing so by setting the AC input current limit to crazy figures like 60 or 70 amps which the Quattro-II is not even capable of according to the datasheet.
Are you using the inverter like a ups type set up?
Possibly something to try. Just disable the power assist function. And set the input current limit where you want it to be.
3D printer and some laptop power supplies are nasty things. Their power factor among other things looks ugly on an osciliscope. So ludo is not offtrack there.
I will try to disable the power assist and I was thinking about it. My concern is that instead of power assistance it will turn my loads off because of detected overload.
But I’ll give it a try anyway.
Not sure what it is but these 3d-printers definitely do something weird to the power source so I totally get it. If I only could do anything about it.
You would likely only get an overload if you exceed the inverter set up ability at the temperature it is operating in. But otherwise there should not be an issue
I’ve discovered the feature called dynamic current limit.
It’s designed not to help in a situation when the AC input power is not sufficient but rather for the cases when AC input is provided by a generator which doesn’t deal with power consumption spikes very good. So the higher the consumption is the higher the generator’s RPMs become.
I’m going to try to disable this feature. I will try it when I receive my Smart dongle. It looks like it will let me disable dynamic current limit via Bluetooth without powering my Quattro off.
What is the requirement for PowerAssist in this use case? It is typically used when the AC source (shore power/generator) is not capable of supplying the full load behind the inverter?
My Quattro powers mission critical loads and works as UPS.
So I need a 100% reliable power without interruption. Most of the time grid (aka utility) is available so it’s just a passthrough. When grid’s not available the batteries become an energy source for a while. But if grid’s not there for a long time I need to use generator before batteries are low.
Hence the generator will power both the loads of mine and the charger at the same time. It’s only 1.8 kW so I have to be very careful with power distribution. I have to make absolutely sure not to overload it.
When running from the grid I need neither dynamic current limit nor a power assist. When running from generator I better have both enabled: DCL to make sure that the generator can keep up with the load change and PA just in case my overall consumption exceeds what generator can provide without overloading.
Yes.
Disabling of dynamic current limit worked so far (when the 3d-printers start printing the short spikes don’t cause power assist to kick in).
Although I there’s no easy way to toggle dynamic current limit. VictronConnect app doesn’t let me do that. Only remote VEConfigure does.
I wish I could configure Dynamic Current Limit algorithm (like threshold values at least), not just enable and disable. Also it would be great to be able to toggle it via Cerbo GX interface or via Bluetooth (using Smart dongle).
