Hi everybody,
I'm adressing this excellent community with the hope it'll help me solve a problem I've run into recently with my Victron off-grid solar installation.
First of all, the components:
12x 390W 144 half-cell solar panels, wired in 6 parallel groups of 2 in series panel.jpg
1x SmartSolar 150/100 MC4 MPPT (v. 1.59) mppt.jpg
1x Quattro 48/8000/110-2x100 (v. 4.30) inverter.jpg
1x ColorControl GX (v. 2.89) ccgx.jpg
3x PylonTech US3000C 48V Lithium Batteries battery.jpg
Up until now I'm incredibly happy with the setup, everything runs smoothly, I also have a small petrol backup generator I haven't had to use since 2020 wired to one of the AC inputs of the Quattro.
Now for the problem:
Recently I installed a pump for the well, which connects to a VFD regulating startup and some filters, everything wired to the AC output of the Quattro. The pump draws continuous 5000W of power. This has brought a problem to light which I had never noticed before:
The MPPT never draws more than 2600W from the panels! Or to be more specific, and this is what REALLY bugs me, it never draws more than a value that seems to be around the Charge Current Limit multiplied by the Maximum Battery Voltage; in terms of the solar array an interval centered around 33A at 75V. pumprun.jpg
Since the Pylontech batteries have their integrated BMS I can't really manipulate any values, all I can tell is that the CCL declared by the batteries is 44A, and the DCL is 111A (or 37A times 3 units, exactly the numbers from the manual). DVCC is activated with all sharings turned off, and the MPPT is running in networked mode as a Slave.
Now, I've checked and double checked, but at this point I think I'm going crazy. From what I understand, in 48V systems, shouldn't the SmartSolar 150/100 be able to produce up to 5800W (as per the datasheet)? Ideally, what I thought would happen, is that the MPPT would draw as much power as possible from the panels, and then "fill up" the remainder from battery power. What is actually happening is quite the opposite, the MPPT only draws up to the 2600W mentioned before and all of the remaining power is drawn from the batteries. During the day and with the panels in full sunlight and at a temperature of around 30ºC this seems quite stupid, as the battery capacity quickly becomes a bottleneck for the amount of time I can run the pump. What am I doing/understanding wrong?
The only thing I haven't tried yet is setting a limit for the charge current in the DVCC. Might this be the crucial point? How is point 4 in subject 8.4.1 in this link to be interpreted? And point 5?
https://www.victronenergy.com/media/pg/CCGX/en/dvcc---distributed-voltage-and-current-control.html
Any help is welcome! Thanks a lot in advance for any hints or ideas!