A novel single-stage HPF electronic ballast with coupled inductors for fluorescent lamps

This paper proposes a novel single-stage electronic ballast with high-power-factor (HPF) for supplying fluorescent lamps. The presented electronic ballast integrates a dual boost converter with coupled inductors and a half-bridge series-resonant parallel-loaded (SRPL) inverter into a single-stage power conversion topology. The features of the ballast are cost-effectiveness, high power factor (PF>0.98), low input current total-harmonic-distortion (THD<;12%), low level of crest factor (CF<;1.4) and zero-voltage switching (ZVS) obtained on both two power switches. Operational principles, design equations and experimental results of one T5-type fluorescent lamp with a rated power of 21 W operating at 50 kHz switching frequency with 110V-rms line input voltage are presented. Satisfactory results demonstrate the feasibilities of the proposed ballast.