Hybrid Multimodule DC-DC Converters for Ultrafast Electric Vehicle Chargers

Abstract

To increase the adoption of electric vehicles (EVs), significant efforts in terms of reducing the charging time are required. Consequently, ultrafast charging (UFC) stations require extensive investigation, particularly considering their higher power level requirements. Accordingly, this paper introduces a hybrid multimodule DC-DC converter-based dual-active bridge (DAB) topology for EV-UFC to achieve high-efficiency and high-power density. The hybrid concept is achieved through employing two different groups of multimodule converters. The first is designed to be in charge of a high fraction of the total required power, operating at a relatively low switching frequency, while the second is designed for a small fraction of the total power, operating at a relatively high switching frequency. To support the power converter controller design, a generalized small-signal model for the hybrid converter is studied. Also, cross feedback output current sharing (CFOCS) control for the hybrid input-series output-parallel (ISOP) converters is examined to ensure uniform power-sharing and ensure the desired fraction of power handled by each multimodule group. The control scheme for a hybrid eight-module ISOP converter of 200 kW is investigated using a reflex charging scheme. The power loss analysis of the hybrid converter is provided and compared to conventional multimodule DC-DC converters. It has been shown that the presented converter can achieve both high efficiency ( and high power density (10.3 kW/L), compromising between the two other conventional converters. Simulation results are provided using the MatLab/Simulink software to elucidate the presented concept considering parameter mismatches.

Hybrid multimodule DC–DC converters accelerated by wide bandgap devices for electric vehicle systems

“…The present study supports the beneficial results associated with multilevel converters in cascade topologies, as previously documented in the literature. Specifically, the suggested paradigm is influenced by a multimodule pattern described in reference 50 . This novel idea seeks to tackle the present obstacles related to ultra-fast electric vehicle (EV) chargers, with a particular focus on the simultaneous achievement of both high power and high switching capabilities 51 – 53 .…”

Special Issue on Power Converter of Electric Machines, Renewable Energy Systems, and Transportation

“…The last two papers deal with the integration of energy storage in power systems. The paper "Hybrid Multimodule DC-DC Converters for Ultrafast Electric Vehicle Chargers", authored by Mena ElMenshawy and Ahmed Massoud, introduces a hybrid converter configuration, based on multimodule dual-active bridge topology for the ultrafast charging of electric vehicles [9]. Finally, the paper authored by Gianluca Brando, Efstratios Chatzinikolaou, Dan Rogers and Ivan Spina, focuses on an analytical investigation of electrochemical cell power losses in modular multilevel converters and their dependence on the injected common mode voltage.…”

Fast-charging anodes for lithium ion batteries: progress and challenges

“…Despite numerous efforts, it is regrettable that the charging speed of the most EVs still cannot meet the requirements of the United States Advanced Battery Consortium (USABC) for fast-charging technology (achieving an 80% state of charge in batteries within 15 minutes). 30,31 Therefore, developing an advanced fastcharging technology is currently the top priority in the battery industry (Fig. 1b).…”