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The PV-to-user line resistance is taken downstream the array output, up to the end-user (vehicle). It should not be confused with the PV-array ohmic resistance, which is distributed along the PV-array connections (see shema).

With undefined load profile (i.e. illimited load), the array output voltage is assumed to be the given "Main power supply" parameter. In this case the voltage at the user level is the nominal voltage minus the line ohmic loss; the supply-to-user line resistance is meaningless, as well as the overvoltage protection.

When a load profile is defined,  the "Main power supply" is the conventional supply nominal voltage. The program determines the user voltage (after the Supply-to-user line resistance voltage drop),  and the PV output voltage (user voltage increased with the PV-to-user voltage drop). The PV current is then calculated according to the array I/V characteristics. The load current is the difference between the PV current and the user's need current. If the PV array cannot deliver it's current due to low load, it's voltage will increase according to the array I/V characteristics, and could reach the overvoltage limit.

All these currents and voltages are interdependent, and have to be calculated from current balances in a loop procedure.