부산대학교 도서관

This paper presents a two-stage single-phase 3.5 kVA on-board charger (OBC) for an electric vehicle (EV) charger that is suitable to be connected to a low-voltage household network. The proposed OBC consists of a front-end converter and a back-end converter. The two-phase bridgeless interleaved converter is used as a front-end converter since it will reduce the current stress on the power electronic switches and improve the overall charger efficacy. For the back-end converter, the LLC resonant network single-active bridge is used to provide galvanic isolation, and it operates a switching frequency high than the resonance frequency to achieve zero-voltage switching. Also, the presented control strategy loops make the proposed OBC have three operating modes (current control mode, fixed input power mode, and voltage control mode) with a smooth transition between the modes during the EV charging process. Finally, the proposed OBC simulation and experimentation are carried out to verify the safe charging operation. Finally, the performance of the proposed OBC and the proposed control strategy was verified using PSCAD/EMTDC simulation, such as first the performance of the current control mode was first tested, and the full charging cycle was simulated.