Street lighting system using light emitting diode (LEDs) supplied by the mains and by batteries

This paper presents a topology and its design methodology to a street lighting system using light emitting diodes. The proposed topology has its main application street lighting systems without energy consumption from the mains during peak-load time or emergency lighting systems, supplying the circuit by batteries when necessary. These applications are justified by the reduction in energy demand from the electric power system and by the increase in the lighting system reliability. The LEDs are supplied via the mains with high power factor by the integrated Buck-Boost Flyback converter, which is also used to charge the batteries. Besides, the same circuit is used to supply the LEDs through the battery, reducing the number of components. The experimental results have been shown that it is possible to implement the proposed topology employing a 20μF non-electrolytic capacitor. This design methodology can also be used for other topologies and applications.