In the mechanism of wireless power transfer in on-line electric vehicle (OLEV), the design of magnetic field
is the key technology to determine its electrical performance of power transfer capacity, transfer efficiency,
and electromagnetic field (EMF) level. To satisfy all the requirements, systematic approach for optimization
of design parameters is required. Even though shielding for reduction of EMF can be applied independently,
the shielding effectiveness of the applicable shielding method should be considered in optimization of design
parameters. In this paper, we introduce the wireless power transfer mechanism and the EMF reduction
techniques, and perform design parameter optimization to maximize transfer power efficiency while
satisfying power transfer efficiency and EMF regulation.