High Power Factor Hybrid Rectifier
This paper presents the analysis of a new single-phase hybrid rectifier with high power factor (PF) and low harmonic distortion current. The proposed rectifier structure is composed of an ordinary single-phase diode rectifier with parallel connection of a switched converter. It is outlined that the switched converter is capable of shaping the input line current waveform, assuring high PF and low total harmonic distortion (THD). The power rating of the switched converter is less than 50% of the total output power; assuring reliability in the proposed hybrid rectifier. A pulse width modulation (PWM) control strategy was developed, imposing quasi-sinusoidal line input current waveform and limiting the switched converter power contribution. It was found that the line input current harmonic spectrum is in accordance with the harmonic limits imposed by IEC61000-3-4. The principle of operation, the mathematical analysis, and simulated results are also presented in the paper.