A single-stage high-power-factor electronic ballast with ZVS buck-boost conversion

This paper proposes a novel single-stage high-power-factor electronic ballast via the integration of a derivative buck-boost converter and a half-bridge resonant inverter. The derivative buck-boost converter employs two coupled inductors with an appropriate turns-ratio to conduct the current from the input line source into the designated power switches. With the tactful topology and delicately designed circuit parameters, both the active power switches of the resonant inverter can retain the zero voltage switching (ZVS), resulting in a high circuit efficiency. A prototype circuit designed for a T8-36W rapid-start fluorescent lamp was built and tested to verify the analytical predictions, and satisfactory results were obtained experimentally.