Im having trouble with an ess system. When there is a power failure in the early afternoon, there is also still plenty solar power available. The problem is that freq shifting is not cutting back power fast enough on the gridtie inverter leading to overvoltages on the battery.
The setup consists of 10kWh lithium pack with 8kVA quattro and 4.4kWp of solar panels on a 4.6kVA solis. The system uses a ac current sensor to monitor pv production.
I have already tested with higher freq values, but still response times are too slow.
Is there a specific grid code which will work better. Currently i have nrs 097 selected.
Any suggestions on what im missing?
Initially power on the gridtie cuts back nicely, but then ramps up and continue to produce at max power until the battery or invertter switches off.