Can PVsyst model a mini-grid system ?

[André Mermoud]

In the present time, the Stand-alone option of PVsyst works with an "energy bus" in DC, directly connected to the battery.

And the user's needs are specified in terms of energy, whatever the way it is used . PVsyst doesn't involve an inverter for Standalone yet (this is in preparation).

Now big Stand-alone systems architectures (like mini-grids for a village) are organized around an AC power line distribution, which is very close to a normal grid. In these situations, they may involve:

- standard Grid inverters for the connexion of the PV array to the mini-grid (with some precautions concerning the grid management),

- specific bi-directional rectifiers/inverters for the charge/discharge of the batteries.

- other sources like diesel gensets, wind turbines, etc, connected to the AC bus.

- a sophisticated grid control system for the stability of the AC-bus distribution behavior.

This is not yet implemented in PVsyst.

Benefits of PVsyst

I admit that this seems indeed rather limited in terms of system management.

However we can consider that the main objective of the PVsyst simulation will be the sizing (and performance analysis) of the whole system, i.e. the battery capacity and the necessary PV array, as a function of the user's needs. The simulation also evaluates the real battery use (charging/discharging energy) for the evaluation of its lifetime.

This "equilibrium" of the whole system and its evolution along the year is not much dependent on the system devices involved in the reality.