A New Hybrid Isolated DC-DC Converter Topology for Realizing Very High Efficiency Isolated AC-DC Chargers

The paper presents a new very high efficiency isolated ac-dc power converter topology. The proposed topology is employed as module to realize a high efficiency dc charger that can be directly supplied from the medium voltage ac grid: the realized function is therefore isolated medium-voltage-ac low-voltage-dc converter. The proposed solution allows higher efficiency than the pair distribution transformer low voltage ac-dc converter and lower cost, which makes it ideal economically, especially when the grid infrastructure needs to be adapted due to a large number of charging stations. A variant of the topology that enables bidirectional power flow is also presented, which allows the efficient and cost effective integration of renewable energies and energy storage. Simulation results are presented as well as an assessment of the losses obtained based on a high precision model that takes into account the losses of all active and passive components.