Power Quality Improvements in Isolated Twelve-Pulse AC-DC Converters Using Delta/Double-Polygon Transformer

This paper presents twelve-pulse AC-DC converters for constant current applications. The delta/ delta-star transformer based 12-pulse AC-DC converter doesn't meet power quality requirements. To overcome this drawback, a delta/double polygon transformer based AC-DC converter is designed, simulated and developed to compare its performance in terms of power quality parameters with that of delta/delta-star transformer based AC-DC converter. To meet power quality requirement over wide range of load variation, pulse doubling technique is used to make it 24-pulse AC-DC converter.