A null-current electro-dynamic levitation system

All electro-dynamic levitation systems (EDS) have peak drag forces and peak and average power consumption to deal with in order to be viable in Maglev applications. Both factors affect the energy cost and the capital cost of the propulsion system. A significant improvement for EDS systems is a so-called null-current configuration. It consists of two Halbach arrays, one above the track and one below the track. The two arrays are oriented with respect to one another so that their horizontal field components add while their vertical field components oppose. In this way, the levitating field component is enhanced while the field component that excites the currents in the ladder-track between the two arrays is weakened. The basic idea is that the lower induced current and the higher levitating field component produce the necessary levitation force. At the same time the drag force is much lower, since it depends on the product of the induced current and the vertical field component.