Electrolytic capacitor-less, non-isolated PFC converter for high-voltage LEDs driving

This paper introduces electrolytic capacitor-less, non-isolated power factor corrected converters for high-voltage LEDs driving. To increase lifetime of the power supply, electrolytic capacitor is substituted to small polyester film capacitor and to insure input power factor(PF) higher than 0.9, conventional Boost and Buck-Boost PFC converters are chosen to drive high voltage LEDs driving due to its simplicity and low cost. The converters operate in boundary mode condition between CCM and DCM to achieve soft switching and high efficiency. 20W Boost and Buck-Boost PFC converters were designed and tested to drive 400V and 200V LEDs each with 0.2uF polyester film capacitor and through experiment 0.99 PF and over 92% efficiency were achieved at full load.