An integrated insulated buck-Flyback converter to feed LED´s lamps to street lighting with reduced capacitances

This paper presents an integrated insulated converter to feed power light emitting diodes (LEDs) for street lighting system applications. A Buck converter was used to implement the power factor correction (PFC) and a Flyback converter to perform the power control (PC). The integration between the power stages was made to increase the system reliability by reducing the number of controlled switches. The system aims to have high power factor and low total harmonic distortion (THD), according to the IEC 61000-3-2 standard. Also is proposed a control technique to regulate the ripple of LEDs´ current, aiming to reduce the necessary capacitance values. This turns possible the use of film capacitors that have a bigger life time them electrolytic caps, general used in these systems.