Grid Limit for Stand-Alone BESS

I am trying to simulate a stand-alone BESS to extract the state of charge curves of the batteries and the power injected into the system. I am considering a grid limitation of 30 MW, however, this limit is only being respected during discharge. During battery charging, the system exceeds -35 MW. Is there any parameter I might be missing?

Moreover, there is a distortion in the power curve during charging. How can I fix this?

Hi Vitor,

The grid limits only constrain exports to the grid. They do not limit imports. This is explained in the Grid Limits Help topic:

 

Based on the manual dispatch parameters on the Battery Dispatch page, the battery is only allowed to discharge to the grid during Period 2 from 5pm to 8pm, and to charge from the grid from 10am to 1pm. The time series plot in the screenshot you shared looks consistent with this dispach schedule.

Best regards,
Paul.

Hi Paul,

Thanks for the reply! 

Is there any chance that the software will implement this feature of limiting energy import in the future? I believe it is very useful because the BESS can use the same power limit authorization for both energy import and export.

The distortion i meant was the spike when the battery starts recharging from the grid (as shown in the attached screenshot).

Hi Vitor,

I think that spike is a plotting artifact rather than real data. If you zoom in to the graph, you should see it disappear. You can also confirm that by looking at the data itself on the Data Tables tab (or by right-clicking the graph and exporting the data from there).

Adding a limit for grid imports is on our wishlist: github.com/NREL/SAM/issues/1957

Best regards,
Paul.