Harmonic mitigator based on 12-pulse ac-dc converter for switched mode power supply

A novel harmonic mitigator based on the 12-pulse ac-dc converter, which is capable of suppressing up to 11th harmonics, is presented with reduced magnetic rating and low total harmonic distortion (THD) of ac mains current. A set of power quality indices on input ac mains and magnetic ratings for various autoconnected transformer configurations for the 12-pulse converter feeding a low voltage, high current and 12-kW switched mode power supply is also presented so that the best autoconnected transformer configuration can be chosen according to the requirements for this application. A laboratory prototype of the proposed ac-dc converter is developed and the test results are presented to validate the design and model of the converter system.