Multimodule ISOP DC-DC Converters for Electric Vehicles Fast Chargers

Abstract

Battery chargers have been developed for many applications such as the automotive industry, utility applications, UPS systems, forklifts, and trucks. Battery chargers for Electric Vehicles (EVs) have been addressed in literature extensively from different perspectives. In this regard, providing a low-cost and high-efficiency fast battery charger is of high importance to enable fast charging solution for EVs, which will accordingly allow for greatly reduced charging times and high penetration of EVs. Since cost and performance are prime design goals, a compact and low-cost fast charger is highly desirable, which can be achieved via employing advanced power electronics technologies and soft switching techniques to yield a high-power density and high-efficiency design. A typical charger consists of two stages: AC-DC stage and DC-DC stage. However, due to the significance of the DC-DC conversion stage in supplying energy to the EV's battery, the main objective of this paper is to present a multimodule DC-DC converter that is series-connected at the input side and parallel-connected at the output side to allow for high input voltage supply and high output current. The Input-Series Output-Parallel (ISOP) DC-DC converter is studied in terms of its small-signal modeling and control strategy. A Matlab/Simulink is provided to present the control strategy that ensures equal power-sharing among the modules, where the output current is controlled based on reflex charging