Quantification and Active Filtering-based Mitigation for Third Harmonic Component Attenuation in Totem-pole PFC for Onboard Charging Systems

To accurately model and characterize the harmonic spectrum of the input current of a totem-pole power factor corrector (TPFC) topology, a comprehensive mathematical model identifying the magnitude and phase of the various harmonic components is formulated in this study. As the effect of third order harmonic is most profound in the frequency spectrum of the input current, a closed-form mathematical model correlating the third harmonic component as a function of the load power, input voltage, and the closed loop controller coefficients of the TPFC is established. Further, with an objective to curb the third harmonic component, a novel digital filter based Active Mitigation Scheme (AMS) is proposed in this study. Extensive simulation and experimental results are included in order to validate the performance of the proposed theoretical model and affirm the effectiveness of the proposed AMS scheme. The results portray an accuracy of 97% of the formulated third harmonic model, when compared with the simulation and experimental results. Moreover, implementation of AMS results in a superior power quality with 0.77% reduction in the Total Harmonic Distortion (THD) while achieving a resultant power factor of 0.998 (lag).