A moving field inductive power transfer (MFIPT) system for supplying power to electric vehicles while driving along the route is described. This MFIPT system uses primary coils arranged below the pavement. The primary coils transmit the energy via an alternating magnetic field to a secondary coil located at the vehicle below its floor. Only those primary coils located below the secondary coil of a vehicle are excited. By this way losses and radiation in the environment are minimized. The operation principle of the moving field inductive power transfer system is based on a switched DC-to-DC converter which converts the DC power supplied by the stationary power line to DC power delivered to the moving electric vehicle. The dynamics, the operating regimes and the power balance of the moving field inductive power transfer system and the costs for the implementation of the system are discussed. The contactless power supply of electric vehicles on highways makes it possible to get along with battery capacities otherwise suitable only for shorter range. The batteries are used only in local traffic and on side roads where no moving field inductive power transfer system is installed. In areas where there are no inductive supply roads available, the inductive energy transmission system may still be used in stationary charging stations. Since only the primary coils below the vehicles are activated, high efficiency is achieved and the magnetic field is shielded against the environment. The MFIPT system is especially interesting for intelligent autonomous electric vehicles. In transportation systems based on this combination the electric vehicles will exchange information with traffic management systems and with each other and thereby achieve a steady, energy-efficient traffic flow even at very high vehicle densities.
«