A bridgeless boost PFC converter fed LED driver for high power factor and low THD

This paper deals with multi-string light emitting diode (LED) driver using a bridgeless (BL) boost converter. This converter is designed for large area LED lighting with illumination control. A multi-mode LED dimming technique is used for lighting control. The BL-boost PFC converter feeds power to an isolated flyback DC-DC converter. The regulated low voltage from the flyback converter is a source of power to the synchronous buck converters for multi-string LED driver and forced cooling system for LED junction. The BL-boost PFC converter inductor is designed based on discontinuous inductor current mode (DICM) which provides good PFC at low cost. The performance of the LED driver is evaluated for a full brightness control capability with low THD at universal input supply (90V–265 V). The power quality parameters observed at AC mains are found within an IEC 61000-3-2 Class C standard.