This paper proposes optimized design of On-Board Charger for electric vehicles. Currently, 6.6kW system
has widely used in electric vehicles. However, their efficiency has less than 91%. To improve the efficiency of
On-Board Charger for electric vehicles, optimized design is performed in component level. As a result,
the performance of this system is increased in vehicle level. The prototype is developed and test is performed to verify optimized design result including the efficiency. In addition, the validity is verified through experimental result for the target efficiency and charge status in actual vehicle level.