How to simulate a DC coupled system

[bshare]

Is it possible to do basic "peak shifting" for a given DC coupled inverter and battery file? What I mean is, store PV energy that would otherwise be clipped in a battery, and then us the extra to extend the AC production for the system into the afternoon as the peak sun window closes for that day? I have tried to use the peak shaving storage scheme to produce this effect but the batteries don't charge at all and the extra energy is still clipped.

Do I need to modify the inverter file, or the storage scheme? What am I missing here?

[André Mermoud]

What you need is indeed provided by the "Grid system", using the "Grid storage" option, "Peak shaving".

However this option doesn't define a DC converter in parallel with the Inverter yet. The Inverter is supposed to deliver the extra-power for the battery, so that it should be sized for accepting the peak power during the best days.

We will develop this feature in a next version. In the mean time, the results with an oversized inverter sould be quite equivalent to a separate DC converter.

[gonecrawfishin]

I think I'm trying to accomplish the same thing. I've used the peak shaving method, and am still finding quite a lot of losses due to batteries being fully charged. When I dove into hourly results, I see that the state of charge of my batteries almost never goes below 50%, despite my minimum discharge being set to 10%. The batteries are not "ready" to absorb the day's solar peak, and they are not discharging their full capacity during load peak hours. The model also does not seem to cycle the batteries every day. Is there a way to force a daily BESS operation in this way?

[IgLoo]

As I see it is still a problem in 7.2 version....

[JNutter]

Hello, I am looking to model a system with DC converters in parallel with inverters. Is the above comment to oversize the inverters to account for the DC converters still the recommendation?

[André Mermoud]

Yes, the DC converters diectly connected to the PV array are not yet implemented in PVsyst.

Please have a look on the help  " Project design > Grid-connected system definition > Grid systems with storage > Grid storage, system architecture "