Project design > DC-grid system definition

This is to be applied to some Public Transport networks, which operate at DC voltage in the 600 - 1500V range. Upper voltages are difficult to carry out because of the maximum allowable voltage of the common PV modules. Such an installation doesn't require power conditioning, nevertheless very heavy safety disconnector devices should be foreseen for short-circuit protection in both directions.

Please :

- give the desired nominal power,

- give the operating DC-voltage of the grid, the maximum allowed voltage on the grid, and line resistance from the array's output up to the end-user (usually a vehicle). The line resistance from the conventional supply to the user should be defined only if a load profile is specified.

- chose the regulation behaviour when the PV-array output voltage overcomes the maximum grid safety voltage.

- choose a PV module model

=> the program determines the number of modules in series and in parallel.

You can now play with these parameters. The program cannot determine the exact optimum of the number of module in series. Therefore you should find this optimum by performing several simulation runs and compare the maximum system yearly efficiency.

If desired (in a second step), you can

- define a user's load profile

- modify the PV-array specific loss parameters (thermal, wiring resistance, module quality, mismatch, IAM) with the "Detailed Loss" button.