Abstract
Recently, high frequency inverters are widely used in the electronic ballasts for fluorescent lamps. A new combined voltage-resonant inverter is presented to suppress the input current harmonic distortion in the electronic ballasts. In this inverter, the voltage-resonant active filter and inverter are combined, and a switch of the active filter is used in common as that of the inverter. The purpose of this paper is to describe the operation of the combined voltage-resonant inverter with an added simple control circuit and to examine its fundamental performance characteristics. As a result, the high power factor, low input current harmonic distortion factor, low crest factor of the output voltage, low voltage stresses on the main switch and the smoothing capacitor can be realized by using the new control strategy in cases of ±10% change of the input voltage or ±20% change of the load resistance as a fluorescet lamp.