EMI Modeling and Optimized EMI Filter Design for PFC Topologies

With the emergence of electric transportation and the infrastructure for electric vehicles (EVs), numerous viable approaches and topologies have emerged. In order to improve the power quality of the grid, it is essential for Onboard Battery Chargers (OBC) for electric vehicles to maintain a power factor closer to unity. This study mainly focuses on two prominent PFC topologies, Totem-pole PFC (TPFC) and H-Bridge PFC (HPFC), which are simple to implement and capable enough of providing high operating efficiency. This study elucidates the comprehensive comparison of the TPFC and HPFC converters using the comprehensive mathematical modeling approach, simulation models, and the hardware experiments. Also, the comparison of the EMI filter requirement and design of DM EMI filter for both the topologies is also extensively illustrated in this study. Firstly, focusing the comprehensive mathematical models of TPFC and HPFC converters, which includes the mathematical formation of the duty cycle for both the converters incorporating the discretized input current controller into the mathematical model which gives more closer comparison when it is compared to simulation models and the hardware experiment model operations. The input current FFT analysis and the THD modeling are also covered in the mathematical modeling of TPFC and HPFC converters. Moreover, the EMI noise is modeled, and the corresponding EMI filter is also designed for both the PFC topologies. Further, the simulation models of TPFC and HPFC converters are also developed and the outputs of the simulation models show an input AC current is precisely following the input AC voltage and also the output voltage of constant 400V is attained for both the PFC converters. Similarly, for the experimental results, the constant 400V regulated DC output voltage is obtained and the input AC current is following the input AC voltage with the power factor of 0.983 for TPFC and 0.99 for HPFC converter. Moreover, the implementation of the EMI filter at the front end of the converter succinctly attenuates the EMI noise and complied within the FCC Class A limit for both TPFC and HPFC converters.