A Review of Electric Vehicle Auxiliary Power Modules: Challenges, Topologies, and Future Trends

The auxiliary power module (APM) is a vital component in electric vehicles (EVs) that enables efficient power transfer from the traction battery to low-voltage electrical loads and the 12 V battery. As the EV industry continues to evolve, APM design is facing increasingly stringent challenges, including the need for higher power ratings, higher voltage ranges, higher reliability, and higher power density, with a continued need for efficient operation. However, there is a lack of literature that comprehensively reviews recent APM topologies based on these evolving requirements. This article fills this research gap by comprehensively reviewing current APM topologies from both academia and industry, including unidirectional and bidirectional topologies, single-stage and two-stage topologies, and multifunctional topologies. Furthermore, this article explores several potential future trends for APM design and development.