Self-limiting Tunnel Lighting System, Powered by a Photovoltaic System

The lighting system of a one-way tunnel serving a junction is considered. Instead of a photometric system for measuring the adaptive luminance L 20 (in the field of view of the driver of the vehicle) sensorless control of daytime adaptive lighting is provided - L 20 . It is calculated by the input voltage U DC_STRING of the photovoltaic system used to power the tunnel. As the panels are oriented to the south and the tunnel entrance is to the north-west, the relationship between the two quantities is determined by hours of the day, for the 12 months of the year, taking into account the unequal irradiation of the two surfaces.