Research Projects

The research aims to design and develop a universal L1-L2 on-board charger (UOBC) compatible with both 1-ph and 3-ph AC supplies, offering the respective benefits of time-multiplexed operation. The core objective is to create a novel, dual-active-bridge (DAB)-based, low device-count, single-stage, bi-directional dc-ac converter that can operate with both 1-ph and 3-ph AC supplies. The proposed circuit should be compatible with both 1-ph and 3-ph AC inputs, use fewer devices than conventional solutions, do not require electrolytic capacitors for energy buffering 1-ph operation, realizes soft-switching of switches, enable higher switching frequency, and allow bidirectional power flow. Various topological variations of the basic circuit will be investigated to compare performance, cost, and size. Main experiments will be conducted to validate the proposed concept and verify the basic operational feasibility of the circuit in both 3-ph and 1-ph modes. Experiments will also demonstrate the effectiveness of the circuit to work with 1-ph AC without requiring electrolytic capacitors. Successful implementation of the proposed approach will result in a compact and efficient universal on-board EV charger that can be charged both in commercial spaces and at the user's home, without any off-board charger requirement. This may offer cost advantages to end users and system installers as only electric vehicle supply equipment (without charger) would be necessary. Additionally, having an OBC solution that can be charged independent of the nature of available AC supply (1-ph/3-ph) and at different speeds can help alleviate "range anxiety" among end-users.