Abstract-The working principles and design equations of four different isolated, bi-directional DC to DC converter topologies (a dual active bridge converter, a series resonant converter and two multiple stage topologies) for a 2kW bi-directional battery charger that can be operated in a wide input and output voltage range are presented in this paper. The results of a detailed mathematical analysis of the converter topologies as well as digital simulation results are used to select the most efficient topology for this specific converter application, where the twostage series resonant converter is identified to be the most promising, with up to 90% efficiency at rated power
