Suppressing noise peak single phase to three phase Ac-ac direct converter introducing deltasigma modulation technique

For ac-ac power conversion, a combination of converter and inverter is usually used. But this method increases the power conversion stages, and increasing conversion stage becomes disadvantage in respect of the conversion efficiency. Moreover, using two converters enlarges the equipment and results in a high cost converter. Ac-ac direct converter converts ac power to ac power directly and can reduce power conversion stage. By the way, according to extension of power electronics fields, the necessity of single phase to three phase power conversion increases. For the purpose of reducing high frequency output voltage noise peaks, this paper proposes a single phase to three phase ac-ac direct converter. The proposed converter introduces delta-sigma modulator and output voltage characteristics are compared with a PWM converter. As a result, it was proved that the proposed converter could reduce high frequency noise peaks and had an advantage of keeping noise regulation.