Max inverter power

Hi all,

I'm trying to understand what the various datasheet figures actually mean and how they interact - perhaps you can shed some light...

We have a hybrid 5.0 inverter with a 9.5kWh battery and 6.56kWp PV array made up of 2 strings of 8 panels.

Battery charge/discharge performance matches the figures listed above. And my understanding was that anything above 5kW on the PV inputs would be clipped. But the other day we hit a peak of 5.75kW solar:

So what's going on here? The input/output numbers above appear to add up. So is it simply that the 5kW is a minimum datasheet value, and in reality it can go above that under favourable conditions? Or that it can do up to 3.3kW battery charge and up to 5kW to house and/or grid at the same time? (Seems unlikely.) Or something else going on? And is the 7.5kWp/string limit just a "you can put this much in without breaking stuff" limit for the purposes of system design?

I'm not unhappy about it, but a little curious!

Cheers,
Jo

Josephiah Or that it can do up to 3.3kW battery charge and up to 5kW to house and/or grid at the same time?

Yes. 5kW is the max AC output. But the battery comes out of the DC budget. (The inverter also consumes some power. I'm not sure if that comes off the AC 5kW output, or from the DC side.)

My current plan is to try to ensure there's some space in the battery around noon, so that, if generation exceeds 5kW, there's somewhere to send the excess, to avoid clipping.

DD ah yes, thanks, that makes sense - there was me overlooking one of the main points of the hybrid architecture!

I'm now wondering if I was perhaps thrown by system sizing calculators that don't treat that aspect correctly - i.e. you put in an inverter size of 5kW and it just lops off everything above that. Well, that's a happy bonus I wasn't expecting 🙂

Had my teardown not been pulled you could see internally how all the DC busses converge:
51.2V Bus gets stepped up to ~ 350V
PV side gets stepped up or down to ~ 350V (depending on what its doing)
both join together to form the same bus then get fed into DC > AC conversion stages and out to the house (which is where the 5kW limit applies)

You will get clipping if your battery becomes full or reaches 100%.

https://givenergymonitor.wixsite.com/tutorials/clipping

Rubikcube that's an interesting complication. I can sort of see what's going on, and can see what the suggested strategy is aiming to do, but without a proper legend (what's the orange trace?) and no Y-axis values, I feel like I'm fighting with one hand tied behind my back!

hoggy thanks, that's a helpful description. Would be nice to have a diagram!

Josephiah posted it a few years back here:
https://community.givenergy.cloud/d/1016-failed-eps/11

I though I understood this…

I’m a bit curious;

Why isn’t the battery charging at 3.3kW then and 1.9kW being exported to the grid (seeing as the battery is only at 57%) ?

Is it because you have got a reduced setting for battery charge selected somewhere? Or maybe the snapshot is lagging? Or something else?

Pete UK yes, sorry, should have pointed this out:
Our original battery was self-limiting (to ~ 300W) after charging for a while at full rate, due a defect causing one of the cells' voltages to be out of line with the others. So I have been running at a reduced charge rate for the last few weeks. GE have accepted it's faulty, and the replacement should be getting installed this Tuesday - looking forward to being able to make full use of it!