Street lighting system based on integrated buck-flyback converter to supply LEDs without energy consumption during the peak load time

This paper presents a street lighting system with high power factor based on light emitting diodes (LEDs). The use of LEDs allows energy saving, high luminous efficacy and high useful life to the proposed system. However, the main characteristic of this work is to develop a circuit that supplies the LEDs by an alternative source (battery) during the peak load time. The peak load time is considered as the period in which the demand for power from the mains is maximum, and therefore the generation of the power plants and transmission lines must be able to meet this demand. In this work, a bidirectional flyback converter with two outputs is used to supply the LEDs by mains and still charge the battery. To supply the LEDs by battery, the same converter is used. Besides, a buck converter is used as Power Factor Correction stage. The integration of these converters is performed in order to reduce the number of components and consequently, the volume and cost of the circuit. The complete circuit was implemented and experimental results are shown in order to validate the design methodology.