Power Clipping

Hello Everyone, I have a question regarding power clipping.
I have 2 DEYE 5KW inverters in my property in Philippines working in a Master / Slave operation. The system can be considered to be 10KW so I believe I should have that power available when all panels are generating to their full capacity (Give or take for losses0
I have 4 solar arrays
2 arrays for each inverter.
I have 2 lithium batteries, one of these is 200AH and is connected to the master, the second battery is 228AH and connected to the Slave. They are connected in parallel to the inverters and linked together with a comms cable
The panels are Trina Solar I2, Pmax 460 W.
I have 7 panels on the Master inverter string 1 and 6 panels on the Master inverter string 2 meaning the master inverter is served by 13 panels X 460 = 5980 Watts. I think this is too much.
I have 7 panels on the Slave inverter string 1 and 6 panels on the Slave inverter string 2 meaning the Slave inverter is served by 13 panels X 460 = 5980 Watts. I think this is too much.
I use "zero export to CT" with solar sell enabled. The energy pattern is "load first"
The system is in the Philippines, the sun shine is pretty reliable most days from 06:00 am to 18:00 pm
This system suffers from "power clipping" I have attached a screen shot from the 17th June which appears to be a classic example of power clipping
The only time this does not happen is if I allow the battery to discharge during the night. Once the sun appears the system charges the battery and will generate up to 9.8 KW during the charging process. As soon as the battery SOC reaches its set point the PV power is once again reduced to below 5KW

Does anyone know why this happens? Why can I not generate up to 9KW of power from the system during a normal day ? I am considering reducing the amount of solar panels to 11 per inverter to bring to array power more in line with the inverter to see if this helps.

Any advise would be most appreciated

Thanks

Dave Jobes

It's only going to produce what can be used.
When the battery is full, you only need enough power for the house loads.
So, that's all that is produced.

We use net metering with this system. Once the battery is charged and we are supplying the house loads I thought we would be able to export the excess power back to the grid. We use zero export to CT with solar sell enabled as per below

Zero export to CT, tells me that nothing is allowed to export past the CT.
Solar sell, allows it to export power through its grid (input) connection.
So the two settings together allow it to send power to the main panel, and stops it from going past the CTs. (As best it can, Zero export is never guaranteed)

There was a good analogy - a pool.
So, your system cannot overload the pool, when it's full [eg your battery] and no Export to a grid allowed - hence the production clipped.

I think maybe better just to use this mode. I was advised by the inverter manufacturer to use zero export to grid but it doesn't seem to be right. This reads as if it will be the better option

I am still wondering if I should reduce the amount of panels as currently I am 980 watts too high on each inverter

Dave12111964 said:

I am still wondering if I should reduce the amount of panels as currently I am 980 watts too high on each inverter

Click to expand...

If your Vdc and Idc at each inverter/MPPT are in a mfg range, then the clipping is OK. It's an oversizing, it will produce more energy in your favor.