Onboard Charger for Plug-In Electric Vehicles

Abstract

A compact and high-performance onboard charging system for plug-in electric vehicles is introduced, integrating advanced power conversion stages for improved efficiency and power quality. The proposed architecture employs a bridgeless interleaved boost Power Factor Correction (PFC) converter for the AC–DC interface and a Phase-Shifted Full-Bridge (PSFB) converter for isolated DC–DC power conversion. Through the adoption of Zero Voltage Switching (ZVS), the system effectively suppresses switching losses while simultaneously reducing conduction losses and harmonic distortion, thereby achieving enhanced power factor and conversion efficiency. A laboratory-scale hardware prototype is developed to experimentally validate the proposed design. The obtained results confirm stable output voltage regulation, high operational efficiency, and dependable battery charging characteristics, demonstrating the suitability of the proposed onboard charger for next-generation electric vehicle applications.

Introduction

The increasing adoption of electric vehicles (EVs), especially small EVs like e-scooters and autorickshaws, has created a need for efficient and compatible charging solutions. Existing systems lack onboard charging capability, limiting flexibility and reliance on external chargers.

This work proposes a two-stage onboard charger (OBC) to improve efficiency and power quality. The first stage uses a Bridgeless Interleaved Boost Power Factor Correction (PFC) converter to convert AC to DC with reduced losses, improved power factor, and low harmonic distortion. The second stage employs a Phase-Shifted Full-Bridge (PSFB) converter to provide voltage regulation, electrical isolation, and efficient power transfer using soft-switching techniques.

The system ensures high efficiency, near-unity power factor, reduced losses, and stable battery charging, making it suitable for modern EV applications. Simulation results validate improved performance, reliability, and compatibility with public charging infrastructure.

Conclusion

The project focused on the design and simulation of a high-efficiency onboard charger intended for plug-in electric vehicle applications. The developed system combines a Bridgeless Interleaved Boost Power Factor Correction (PFC) stage with a Phase-Shifted Full-Bridge (PSFB) DC–DC converter to achieve improved input power quality, stable voltage regulation, and enhanced conversion efficiency. The AC–DC stage effectively improved the input power factor and reduced harmonic distortion, ensuring better interaction with the utility supply. The PSFB stage provided galvanic isolation and controlled voltage step-down using phase-shift modulation and Zero Voltage Switching (ZVS), which reduced switching losses and improved overall reliability. Both simulation and prototype evaluations demonstrated stable DC output, minimal ripple, and consistent battery charging behavior. The results indicate that advanced power converter topologies can be successfully implemented in compact onboard charging systems. With further refinement and scaling, the proposed design has strong potential for practical deployment in small and medium electric vehicles, supporting efficient and sustainable charging solutions.

References

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Copyright

Copyright © 2026 Darshandev K B, Meera Lal, Sajin S Sajeev, Surya Saji, Binoj Thomas, Smitha Paulose. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.