Bidirectional soft-switching DC/DC converter for highly efficient EV chargers: Comprehensive analysis of a 20 kW CLLLC converter prototype for

The increasing utilization of high-power chargers for electric vehicles (EV) and electricity from renewable energy poses major challenges. Emerging topologies such as the CLLLC converter can be key enablers for powerful yet inexpensive EV charging and may also improve integration of renewables into the grid. The CLLLC converter, a bidirectional, galvanically isolated, soft switching DC/DC converter, can be used to charge EVs or return energy to the grid. This paper presents theory, design and results of a 20 kW CLLLC converter prototype using SiC MOSFETs and synchronous rectifying with an efficiency of 98 %.