Optimum Transient Surge Protection for EV Chargers

This application note outlines the selection of optimal transient surge protection components for electric vehicle (EV) on-board chargers (OBCs). It discusses the severe automotive environment that poses risks to sensitive electronics, particularly during charging when exposure to overvoltage events from the power grid can occur. The document details various protection technologies, including Metal Oxide Varistors (MOVs), Transient Voltage Suppressors (TVS), Gas Discharge Tubes (GDT), and SIDACtor protection thyristors. It emphasizes the importance of combining these technologies to achieve optimal performance and cost efficiency. The note also highlights the challenges faced by design engineers in selecting the right components to protect power semiconductors from damaging voltage transients. Additionally, it references relevant standards such as IEC 61000-4-5 and IEEE C62.41.2-2002, providing guidelines for surge immunity and component selection criteria. The document concludes with a comparison of protection performance and the advantages of using a SIDACtor and MOV combination for enhanced reliability.