Could anyone help explain what happens when a solar pv grid tied inverter is connected to a voltage optimiser? I thought that the pv inverter exported power to the grid by raising its voltage slightly above the grid voltage, could lowering the voltage stop the inverter from exporting?

 

A PV grid tied inverter usually acts as a current source with a 'isolation' inductor/filter between the inverter output and the grid. If the utility voltage is below the grid inverter line qualification limits (anti-islanding) then yes, it will stop exporting.
The inverter's output matches voltage and frequency to the grid and pushes current to deliver power as if the grid was a infinite load.

 

An optimiser is designed to go between supply and load, and a grid-tied inverter belongs on the supply side of the optimiser, not the load side.

 

So if the grid voltage is 246v and the optimiser is lowering it to 230v will the pv inverter be syncing to the 230v that it is seeing on the supply side of the optimiser? And would there be any issues with it being able to push current back into the grid? Also the inverter is bidirectional so it draw power from the grid to change the connected batteries
Thanks guys.

 

So if the grid voltage is 246v and the optimiser is lowering it to 230v will the pv inverter be syncing to the 230v that it is seeing on the supply side of the optimiser? And would there be any issues with it being able to push current back into the grid? Also the inverter is bidirectional so it draw power from the grid to change the connected batteries
Thanks guys.

I don't think the inverter will qualify (export power) the grid-tie connect on the load side of a 'optimizer' unless it sees a low impedance connection to source current into but it's worth a try as some inverters (PV, Hybrid and AC coupling) have limited 'island' capabilities.
https://www.solaris-shop.com/sma-su...-ready-dc-disconnect-ul1741sb-120-240-208vac/

Edit: change to load side of optimizer.

 

So if the grid voltage is 246v and the optimiser is lowering it to 230v will the pv inverter be syncing to the 230v

Again, the grid-tie inverter goes on the GRID side of the optimiser, NOT the load side. So in your example here, the inverter will always see the grid voltage = 246V, not the optimiser output of 230V.

 

I don't think the inverter will qualify (export power) the grid-tie connect on the supply side of a 'optimizer' unless it sees a low impedance connection to source current into but it's worth a try as some inverters (PV, Hybrid and AC coupling) have limited 'island' capabilities.
https://www.solaris-shop.com/sma-su...-ready-dc-disconnect-ul1741sb-120-240-208vac/
[/QUOTE

Again, the grid-tie inverter goes on the GRID side of the optimiser, NOT the load side. So in your example here, the inverter will always see the grid voltage = 246V, not the optimiser output of 230V.

sorry i should have been a bit clearer in my original question, i have come across this setup in an existing install and i'm unsure about what effect it will have on the system, the customer was told it was installed the mitigate voltage spikes that were causing the inverter to shut ( i don't know if that is actually true)

 

sorry i should have been a bit clearer in my original question, i have come across this setup in an existing install and i'm unsure about what effect it will have on the system, the customer was told it was installed the mitigate voltage spikes that were causing the inverter to shut ( i don't know if that is actually true)

What's the KVA/WATTS size of the 'optimizer' (not sure exactly what that means here) and model number/name? The ones I've seen overseas on the utility AC side are usually a tapped autotransformer with MOV protection similar to this.