Desenvolvimento de um sistema eletrônico com alto fator de potência para iluminação de exteriores empregando LEDs

Abstract

The use of LEDs in lighting systems has been increasing each day, due to its long life cycle and luminous efficiency. However, they need a driver to be triggered. The main objective of this work is to develop a topology to drive the LEDs that has long service life and meets IEC 61000-3-2 standard, which imposes limits on the harmonic content of the driver input current. It will present the design of a driver that consists of two converters, buck-boost and buck, to correct the power factor and power control the load, respectively. Both converters are integrated, sharing a single active switch, making it a single stage driver. It will be also developed a control loop for the driver to correct the LED current. One of the paper goals is to reduce the bus capacitor. Generally electrolytic capacitors high capacitances, but on the other hand these capacitors have shorter life than the other components used in electronic circuits, hence it will limit the life of the driver, limiting one of the advantage of LEDs that is its long life cycle. For those reasons, it is sought to reduce the bus capacitor to apply high lifetime capacitor technologies, making the life cycle of the driver compatible with the LEDs.