A critical-conduction-mode single-stage power-factor-correction electronic ballast

Abstract

A critical-conduction-mode single-stage power-factor-correction (PFC) electronic ballast is presented in this paper. The proposed ballast combines the power-factor-correction stage with a conventional half bridge DC/AC inverter into a single-stage to reduce the cost. The power factor correction stage is a boost-like converter operating in critical conduction mode so that a high power factor is achieved naturally. By exploiting voltage divider, the ratio of line peak voltage to DC-bus voltage can be chosen as a large value of near one, yet a good power factor can be achieved. Theoretical analysis and experimental results for two 45-watt fluorescent lamps are presented.