Design of a high-power factor offline led driver employing a ?uk-based low frequency pre-regulator

摘要

This paper presents a discussion about the use of a low frequency ?uk-based pre-regulator as an offline LED driver and its application to a street lighting LED luminaire. This AC-DC converter may provide high power factor, low input current distortion and compliance with IEC 61.000-3-2 Class C standard, which limits the emission of harmonic currents of lighting equipment. The analysis of the ?uk pre-regulator is revised and a simplified method of microcontrolled control is proposed. Experimental results are shown to an LED luminaire which delivers around 80 W to the lighting devices. For the presented prototype, no electrolytic capacitors are required, which define an extended lifetime for this driver. Moreover, the proposed LED driver can make use of conventional choke inductors employed in nowadays HID-ballasts.