Implementation of an HB-LED driver with PFC and output power control

This work presents a novel HB-LEDs driver designed to solve some of the problems found in commercial LED lamp drivers. This driver includes dimming capability designed for intelligent lightning applications and incorporates a power factor correction method (PFC) to prevent negative effects of current distortion over the mains circuit. The circuit is composed by two main sections: power section and control section. The power section consists on a multi level electronic power converter where the first stage has a boost topology with a current controller performing the PFC function, based on hysteresis comparison.

The second stage has a buck topology and it is designed to regulate the powerdelivered to the LED strings. Both stages are coupled with a digital controller which additionally serves to establish and track a power reference for the LED strings in order to vary the light intensity. A prototype was built based on the design for evaluation. The design implementation provided data that was analysed in terms of efficiency, harmonic distortion and power factor according to regulatory standards. The results were compared with commercial LED lamp drivers characteristics, obtaining significative improvement in energy quality indicators.