A Comparative Analysis of DC–DC Resonant Converter Configurations, Modeling Methods, and Modulation Control Strategies for Battery Chargers

As electric vehicles (EVs) continue to gain widespread adoption, the need for highly efficient
charging infrastructure capable of enabling faster charging has become increasingly important.
Modern EVs are equipped with larger battery capacities and extended driving ranges, which
require advanced fast DC charging solutions to meet their rapid charging needs. Resonant DC–
DC converters are extensively utilized in electric vehicle (EV) applications because of their
superior efficiency, ability to achieve soft switching, and reduced electromagnetic interference
(EMI). Among these, LLC and CLLC topologies offer high power density and reliable
performance over a wide operating range. This article reviews resonant converter
configurations, modeling techniques, and control strategies, and addresses the challenges
associated with nonlinear resonant tank behavior. Various converter configurations were
analzsed with respect to their efficiency, scalability, and regulation complexity. This also
highlights that the unidirectional LLC resonant converter provides an optimal balance between
simplicity, cost, and performance for EV charging applications.