Engineering Safe and Compliant EV On-Board Chargers

This whitepaper outlines the essential protection requirements for electric vehicle (EV) on-board chargers (OBCs), which are critical systems converting AC power to DC for charging high-voltage battery packs. The document details the four key pillars of OBC protection: overvoltage, overcurrent, electric shock, and overtemperature. It explains the risks associated with each category and how TDK's components are designed to mitigate these risks while ensuring compliance with stringent regulatory standards from organizations such as UL and IEC. The paper also presents a complete protection circuit example to illustrate the integration of these components in a real-world OBC architecture. Furthermore, it discusses the layered protection strategy necessary for OBCs to handle various electrical and thermal stresses, emphasizing the importance of robust design practices to maintain safety and reliability in EV charging systems.