High power factor neutral point type converter

This paper presents a new single phase AC/DC rectifier circuit namely neutral point type converter. The circuit offers high switching frequency operation with input current harmonic kept at minimum through the use of active filtering technique. Two active devices are used in this circuit but when applied to the electronic ballast, no additional switching elements and control circuit is required. The converter was applied to the electronic ballast and tested with NIPPO FLR36T6W and results shows that it runs safely and achieved unity power factor. Furthermore the neutral point type buck-boost converter reduces inrush current by eliminating the closed circuit between the input voltage and the electrolytic capacitor. Compared to conventional electronic ballast for fluorescent lights, this circuit manages to achieve the same power factor with reduced circuit elements and control circuit.