Study of different topologies of DC-DC resonant converters for renewable energy applications

DC-DC resonant converters are increasingly used in renewable energy systems and hybrid electric vehicles because of their high power density and high efficiency. This paper establishes a global study of the most popular topologies of DC-DC resonant converters that is series, parallel, series-parallel, LLC and CLLC resonant converters. First harmonic approximation method (FHA) is used to define the equivalent circuit and to analyse the gain characteristics and limitations of each topology.