Power limiting bug (7.4) ?

[Sylvai Vitali]

Hello,

When I activate or deactivate the option to enable power limiting, it doesn't work.

For example, here, I had limited the power to 273 kW and although I deactivated the option, I still have an installation that will not produce more than 273 kW...

Even changing the sytem, and lauching again the simulation, the power limitation still in place, and a green light appear on the energy management box:

When I click on it and go on the power limitation, the box isn't activated... Am I wrong or is PVSyst bug? I've tried to restart and I can't remove the clipping.

In the past week, I add another Issue that wouldn't allow me to use the power limitation...

 

Thank you for your help.

Sylvain Vitali

[André Mermoud]

We don't know any problem of this kind.

Please send your project to support@pvsyst.com, by using "Files > Export project" in the main menu.  And tell us exactly what you are doing for getting this problem.

[André Mermoud]

I had a look on your project.

The problem is not linked to the grid limitation, nor the inverters nominal power.

In your simulation there is already a limitation at the PV array output  (EArrMPP), which never exceeds 289.78 kW. This limitation is due to the use of SolarEdge optimizers.

 

The output current of the optimizers S440 WW is limited to15 A. With SolarEdge inverters, the input voltage is fixed, here 750 V for this inverter.

Therefore a maximum power for one string = 750V * 15A = 11.25 kW.

In your system, you have 26 strings, i.e. a max. power of 26 * 11.25 = 292.5 kW.

After some losses (mismatch, wiring), there is 289.78 kW remaining at the output of the array.

 

NB: You will retrieve this loss in the loss diagram  "Current overload losses"

One solution for avoiding this problem would be to limit the number of optimizers in each string.