BEV/PHEVs provide a number of advantages including superior driver comfort and lower emissions. However, there are a number of technical challenges which still impede their widespread adoption, such as the unexpected and unbalanced load on the grid, and cost and range anxiety. Therefore, power suppliers and automotive manufacturers are working towards V2G technology to reinforce the reliability and capability of the grid, enable end customers to reduce overall BEV/PHEV cost with V2G paybacks, and provide faster bi-directional charging capabilities to alleviate the range anxiety. In this project we will develop a novel universal modular on board charging system implementing the single-phase and three-phase bi-directional charging at a reasonable cost. This new technology will enable the BEV/PHEV charging systems to achieve V2G capability with reduced volume, maximised commonality while addressing concerns of reliability, fault protection and operating in the severe automotive environment with high efficiency. This will provide the vehicle manufacturers with V2G on board charger to install within their vehicle and so encourage the uptake of electric vehicles. Developing high efficient bi-directional OBC is challenging due to the new requirements of bi-directional power factor correction and soft switching, etc.. This project will develop a superior OBC by implementing advanced devices, packaging technology, and control method to push the envelope beyond the state-of-the-art.