Project design > Stand alone systems definition

During the early stage of a stand-alone system study, the main issues are the global system sizing, i.e. the determination of the Battery pack, the PV array power, as function of the user's needs and the meteo conditions. After the quick pre-sizing evaluation, the results (PLOL, unused energy) have to be assessed with a detailed hourly simulation.

The exact regulator strategy doesn't matter. To get rid of the control constraints, PVsyst introduces a general purpose "generic" universal controllers, for the 3 different strategies: Direct coupling, MPPT converter or DCDC converter.

During the sizing process (specification of the battery pack and PV array), these special devices will adapt their parameters to the system, in order to always stay compatible with a normal behavior without control losses during the hourly simulation.

The main parameters to be adapted are:

-	The control thresholds: their default values are specified in the "Hidden parameters" in terms of SOC. But you can change them for threshold's dependency studies, and eventually define them in terms of Battery voltage..

-	Temperature corrections for the battery voltage thresholds

-	With Power conditioning units, the input Voltages and Power according to the modules of the array, as well as the efficiency curve. The efficiency values (Euro and Max efficiencies) may be explicitly modified.

-	The maximum Charging, Load and Back-up currents,

-	Management of the back-up control if a Genset is specified.

All these parameters are stored in your calculation version, therefore keeping also your modifications.

If you want to keep a specific configuration for further use, you can always save this Universal converter with the present parameters. In this case please give it a significant name to the Manufacturer and Model parameters. You are advised to save it under a name like "Manufacturer_Model.RLT in your own database.

Universal controller

Universal controller