During peak solar times around the middle of the day, my MultiPlus II sometimes will disconnect from the grid in times of high voltage (as required), because it does not throttle back the power being exported (soon enough).
Powercor say my grid voltage is within specification, yet I find it usually is not possible to export 5kW to the grid without exceeding high voltage limits. (Maybe they keep the grid voltages high on purpose!)
To me, the problem lies with throttling back PV sources.....and I question whether it is the Grid code, V1-V4 values for Volt-Watt response curve that trigger the throttling?
My settings (pictured) do not match those that my distributor (Powercor) recommend, where they say V3=253 and V4=259.
In my case, I have a DC-coupled MPPT charger which does throttle back, albeit a little late....
Also I have an AC-coupled Fronius inverter which I was told before commissioning that it would be controlled via frequency shifting. This I believe cannot happen whilst connected to the grid and instead can only happen through a Modbus TCP connection. Throttling will work using Modbus, but again too late!
--> What settings will allow throttling to occur sooner?
Furthermore, when using Modbus the GX device shows the Fronius connection as (sunspec) and the Fronius status as "Running(Throttled),
versus not using Modbus it shows the Fronius connection as (solarapi) and the status as "Running".
When using Node-RED to retrieve data, sunspec & solarapi behave differently - with solarapi giving better information for Status and Error codes.
--> Can we use Modbus for throttling, and also use the solarapi connection?
Any help appreciated!