Reduced switching state multilevel improved power factor converter for level-3 electric vehicle applications

Abstract

In this study, an off-board multi-terminal dc charger with active input current shaping for level-3 electric vehicle (EV) charging applications is proposed. The configuration is based on reduced switching state multi-point clamped, three phase improved power factor converter and supplied by the standard ac grid. The topology has the advantage of reduced device count along with reduced maximum device stress. This will increase the speed of EV charging and enables the reduction of capital and maintenance costs of the charging facilities, enhancing further expansion of the eco-friendly transport. In addition, one of the key performance indicator, i.e. the fault ride-through capability, is investigated in the proposed topology under various unbalanced input conditions. Further, steady-state and transient performance of topology during load, as well as, dc-link voltage change is presented. Minimum distorted and balanced line currents are drawn from supply by implementing negative sequence elimination control algorithm. The validation of the proposed topology is verified with simulation and a down-scaled experimental setup. ©The Institution of Engineering and Technology 2019.