A Magnetic-less DC/DC Converter with Pulse Charging for 800 V Powertrains from 400 V DC Fast Chargers

In this letter, a magnetic-less DC/DC converter with a pulse-charging scheme is developed to achieve voltage compatibility between a DC fast-charging station and a high-voltage battery in an electric vehicle. It supports charging an 800 V battery system by typical fast-charging converters having an output voltage of 280 V to 420 V. The converter has a smaller component count than the existing ones, resulting in cost savings and loss reduction. In addition, the topology is operated at a low switching frequency to reduce the switching loss. Battery impedance has been examined by electrochemical impedance spectroscopy to determine a range of pulse frequencies, and the feasibility of the topology has been validated through an experiment with lead-acid batteries.