@inproceedings{29849,
  abstract     = {{DC-DC converters for on-board chargers (OBC) of electrical vehicles are usually galvanically isolated allowing modular single-phase PFC front-end solutions, but require transformers which are more bulky, costly and lossy than inductors of non-isolated DC-DCs. Furthermore, for vehicle-to-grid applications, bidirectional converters with transformers are generally more complex and have a higher count on semiconductor switches than transformerless solutions. However, when using non-isolated DC-DC converters within an OBC, the large common-mode (CM) capacitance comprising capacitive parasitics of the traction battery as well as explicit Y-capacitors connecting the high-voltage DC-system (HV-system) within specific HV-loads to ground has to be considered. For the PFC front-end stage, when supplied from the three-phase mains this means that generation of high-frequency and high-amplitude CM voltages, as it is common e.g. with the conventional six-switch full-bridge converter, has to be strictly avoided. For this reason, a modified topology is suggested leading to a different mode of operation and to a very low common-mode noise behaviour: The three-phase four-wire full-bridge PFC with split DC-link, whose midpoint is connected to the mains neutral provides very stable potentials at the DC-link rails and therefore it can be classified as Zero-CM-topology.For dedicated single-phase operation, as required for most OBC, an additional balancing leg may be added to the topology to reduce the required DC-link capacitance and allow non-electrolytic capacitors.The function of the bidirectional Zero-CM three-phase four-wire full-bridge PFC was verified by simulation and on an 11 kW-laboratory sample. The power factor is above 0.999 and an efficiency of 98 % is measured.}},
  author       = {{Strothmann, Benjamin and Schafmeister, Frank and Böcker, Joachim}},
  booktitle    = {{2021 IEEE Applied Power Electronics Conference and Exposition (APEC)}},
  keywords     = {{Three-phase four-wire, OBC, Y2G, PFC, CM, EY charger, balancing circuit}},
  publisher    = {{IEEE}},
  title        = {{{Common-Mode-Free Bidirectional Three-Phase PFC-Rectifier for Non-Isolated EV Charger}}},
  doi          = {{10.1109/apec42165.2021.9487462}},
  year         = {{2021}},
}