In this paper, a 24-pulse AC-DC converter is designed, modeled, simulated, and developed to feed non-isolated varying loads. The proposed AC-DC converter configuration consists of an auto-transformer based on zigzag connection to overcome current harmonic problems in AC mains. It improves power quality at AC mains and it meets IEEE-519 standard requirements at varying loads. A set of power quality indices on input AC mains and on DC buses for a load fed from 6-pulse and 12-pulse AC-DC converters is also given to compare their performance. It is observed that input current total harmonic distortion(THD) of less than 8% is possible with the proposed topology of AC-DC converter at varying loads.