Technological feasibility of coaxial contactless power transmission for traction power supply

This paper discusses feasibility of contactless power transmission technology for power supply in electrical railways. In recent years, contactless power transfer has been developed because of convenience for charging electric vehicles and electric railways. However, the efficiency of the contactless power transmission is lower than conventional contact power transmission. Furthermore, in order to transfer megawatt power, large size core is required. To accomplish high efficiency and high power density, new power transmission system based on a coaxial cable model with an air gap is presented in this paper. Mathematical model and some simulation results are shown for verification of the proposed system. Power transmission efficiency of 92.7 % is achieved in preliminary experiments.