An input current shaper using a Class-DE rectifier to meet IEC 61000-3-2 Class-C standard processing a small part of the total power

Abstract

This paper proposed an electronic ballast that uses an input current shaper to reduce the total harmonic distortion of the line input current, that only process a small part of the total power. Base on the minimum value of the conduction angle to satisfy the requirements of the IEC 61000-3-2 Class-C standard, the conduction loss of the ICS stage can be reduced. The input current shaper is achieved by using a bridge rectifier which acts as the Class-DE resonant rectifier. By using this topology the conduction angle of the diode can be increased to high enough for satisfy the IEC 61000-3-2 Class-C standard requirements. The proposed electronic ballast is designed for 36-W fluorescent lamp and operated at a line rms voltage of 220 V, a line frequency of 50 Hz with the switching frequency fixed at about 76 kHz. The experimental results show that the total harmonic distortion is 29.5%, the power factor is 0.96, a lamp-current crest factor is 1.42, and 95.2% efficiency at full power.