[TRNSYS-users] multiple inverters

[David Bradley]

David,
>
> 1) Would it be better to use the combined PV inverter model or have 
> separate PV and Inverters?
>
I would tend towards trying to keep the simulated system as close as 
possible to the actual system ; so separate PV and inverter models. The 
exception is that most of the PV models have a maximum power point 
tracker built into them while in reality, MPPTs are usually part of the 
inverter or the charge controller.
>
> 2) As my actual system uses 4 inverters how can I make them common 
> with the main power conditioning unit? I can't link these in the 
> simulation studio. In the real system this controls whether we use 
> power from the PV array, battery array, mains or diesel generator.
>
Again, I would take guidance from the actual system. If the PV strings 
are each connected to their own inverter and those inverters all feed 
into the power conditioning unit, you can probably combine the inverter 
output with an equation and pass it on to the power conditioning unit. 
If the power conditioner is doing clever things with the power at its 
input then you may be best off writing a new component to model how it 
interacts with the PVs and with the load since this tends to be very 
specific to a given project. You might look at the project profile that 
was written on a hybrid power system that included wind, pv, fuel cells, 
a battery bank, and an electrolyzer a few years back. We tried for 
awhile to use existing controllers but quickly realized that the logic 
that was built into the actual system's controller would be much better 
modeled with a custom component. 
(http://www.trnsys.com/ProjectProfiles/FuelCellsProjectProfile.pdf)

Kind regards,
 David




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