A General Impedance-Emulating Digital Control of Single-Phase Rectifier for High Power Factor

This article presents a general impedance-emulating control method for single-phase rectifiers. To repress the harmonic currents due to the distorted input supplies, a general harmonic impedance based on the concept of repetitive control is emulated. To realize unity power factor, a negative inductor-emulating technique based on the extremum-seeking scheme is applied. In this method, the input voltage sensor is not needed, so the cost is reduced and the reliability is improved. The experiments are conducted to verify the effectiveness of the proposed method.