Advanced Architectures and Control Methodologies for the Integration of On-Board Chargers and Low-Voltage DC-DC Converters in Electric Vehicles

Jian Sun; Yuetao Li; Bin Zhang

doi:10.54691/pmxevs90

Authors

Jian Sun
Yuetao Li
Bin Zhang

DOI:

https://doi.org/10.54691/pmxevs90

Keywords:

Electric Vehicles; Integrated OBC-LDC; Dual Active Bridge; Zero Voltage Switching; Magnetic Integration; Power Density.

Abstract

The integration of the On-Board Charger (OBC) and the Low-Voltage DC-DC Converter (LDC) represents a critical evolution in Electric Vehicle (EV) power electronics, aiming to maximize power density and minimize weight. However, conventional magnetically integrated topologies, such as those utilizing three-winding transformers, often suffer from severe cross-regulation and poor light-load efficiency during standalone LDC operation. This paper proposes a comprehensive analysis of a decoupled "2-Transformer" architecture that mitigates these drawbacks. We present a rigorous mathematical model of the Dual Active Bridge (DAB) and Phase-Shift Full-Bridge (PSFB) stages, deriving precise Zero Voltage Switching (ZVS) boundaries and voltage gain equations. Furthermore, a unified Dual Phase Shift (DPS) control strategy is analyzed to manage simultaneous power flows while decoupling the high-voltage and low-voltage control loops. Experimental data from recent literature is synthesized to validate the theoretical models, demonstrating that the proposed architecture can achieve efficiencies exceeding 96% in simultaneous mode while significantly improving thermal performance compared to legacy systems.

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References

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