This paper proposes a control method of reducing the dc-link voltage double line frequency ripple in AC-DC converters. The proposed method utilizes variable duty cycle control, allowing for a reduction in the dc-link capacitance, thereby decreasing the size and cost of the converter. Additionally, the proposed control method eliminates the need for a current sensor, which is typically required in conventional harmonic input current injection techniques. This paper provides detailed mathematical analyses and design procedures for a boost PFC converter with the proposed control method. Furthermore, computer simulation and experimental results are included to validate the effectiveness and performance of the proposed control method.