The automotive landscape is on the brink of a significant transformation, driven by advancements in power electronics. A recent study led by Alessandro Reali, from the Department of Electrical, Electronic, and Information Engineering “Guglielmo Marconi” at the University of Bologna, reveals a groundbreaking development in on-board charging technology that could redefine electric vehicle (EV) performance and efficiency. The research, published in the journal Micromachines, introduces a 6.6 kW on-board charger (OBC) that utilizes gallium nitride (GaN) power switches, a move that promises to elevate the standards for electric and hybrid vehicles.
In an era where the electrification of transport is not just a trend but a necessity, Reali’s team has harnessed the unique properties of GaN to create a charger that operates at higher switching frequencies than traditional silicon-based systems. This innovation is particularly relevant as the demand for efficient power converters grows alongside regulatory pressures to reduce carbon emissions. “The integration of GaN technology allows us to achieve a power density that was previously unattainable with silicon devices,” Reali stated, highlighting the potential for reduced size and weight in future EV designs.
The 6.6 kW OBC is designed to facilitate bi-directional power flow, meaning it can not only charge the vehicle’s battery but also discharge energy back into the grid or power other devices. This flexibility is crucial as the automotive industry shifts towards more sustainable energy solutions. The charger operates on a wide range of AC input voltages and is optimized for use with 400 V nominal voltage battery packs, which currently dominate the market. Interestingly, while the share of 800 V systems is anticipated to grow, around 80% of battery electric vehicles (BEVs) still rely on the 400 V architecture, making this development particularly timely.
The research emphasizes the importance of high efficiency in power electronics. The prototype charger achieved an impressive 96% efficiency and a volumetric power density of 2.2 kW/L, including its cooling system. This level of performance not only meets but exceeds current industry standards, suggesting that future iterations could push these boundaries even further. “We are just at the beginning of what GaN technology can achieve in automotive applications,” Reali remarked, hinting at a future where such innovations could significantly lower costs and enhance performance across the board.
The implications of this research extend beyond performance metrics. As manufacturers seek to meet stringent environmental regulations and consumer demands for faster charging times, the adoption of GaN technology could become a key differentiator in the competitive EV market. With the continuous evolution of battery technologies and the growing infrastructure for electric vehicles, the integration of such advanced charging solutions is not just beneficial; it is essential for the industry’s future.
As the automotive sector continues to embrace electrification, the findings from this study could pave the way for a new generation of power electronics that prioritize efficiency, compactness, and sustainability. The collaboration between academia and industry in developing these technologies will be pivotal in shaping the next wave of electric and hybrid vehicles, making them more accessible and appealing to a broader audience.
For more information on this research, visit the Department of Electrical, Electronic, and Information Engineering “Guglielmo Marconi” at the University of Bologna. The article is available in the journal Micromachines, which translates to “Micromachines” in English.