Thermal Management and Electronic Packaging of a 3.3 kW High Frequency On-Board Charger for EV Applications

Global electric vehicle (EV) adoption continues to surge, driven by advancements in power electronics and battery technologies, has significantly increased the demand for fast and efficient charging solutions. On-Board Chargers (OBCs) are preferred over off-board chargers for their portability, compactness, and ease of integration. However the challenge in OBC are effective electronic packaging with efficient thermal management. This paper presents the development of a 3.3 kW OBC, emphasizing innovative thermal management and packaging strategies tailored for compact, high-performance twowheeler applications. To meet the design demands of efficiency and compactness, wide bandgap (WBG) devices, particularly Gallium Nitride (GaN) transistors are used. The proposed OBC operates at high switching frequencies, to reduce the component size. Further, these advancements lead to significant challenges in thermal management. Thermal simulations were conducted in SOLIDWORKS ${ }^{T M}$ and analyzed with heat distribution, optimized cooling strategies, and validated the innovative enclosure-integrated heatsink design with electronic packaging. The system’s performance was experimentally validated, and the results confirmed effective heat dissipation paths, thereby ensuring safe operation within specified operational limits. The final design achieved a power density of $40 \mathrm{~W} / \mathrm{in}^{3}$ with the converter peak efficiency of 97%. The compact design also complies with IP65 standards, making it highly suitable for twowheeler applications. This research highlights advanced thermal management techniques and optimal power electronic packaging to achieve higher power density and efficiency in OBCs. The proposed OBC design paves the way for the development of faster and more efficient DC charging solutions in EV applications.