A study of an Electrical Vehicle Battery Charger's DC-DC Stage

This paper presents a comparison between a LLC converter and a phase shifted converter in an electrical vehicle (EV) charger application. The aspects considered for this comparison include efficiency, size and cost. The application will target the Level 1 on-board charger class with an aimed maximum output power of 1 kW A short presentation of the EV market trends and the emerging standards in this industry will help outlining the battery charger classification and demands. A step by step design procedure is further described for the two topologies. The mathematical models used are validated by simulations (carried out in PSIM), and provide a mean of computing the power components ratings and constructing a preliminary bill of materials for each of the proposed topologies.