Due to growing globalisation, efficient passenger transport becomes increasingly important. Eddy current brakes will make a decisive contribution in achieving this task, as already demonstrated successfully on ICE3 trains. Providing additional braking forces which are totally independent of any adhesion, the problem of limited force transmission between wheel and rail can be solved as well as the thermal limitation of classical friction brakes. Thus, the cruising speed can be increased and larger track gradients can be handled. Furthermore, the cost intensive wear of friction materials can be reduced significantly. Through a next generation of eddy current brakes, further potential shall be accessed. The primary focus for this new generation lies on the improvement of the robustness and the reliability of the eddy current brake with the purpose of increased availability. Fundamental target therefore is the reduction of energy consumption. Today's eddy current brakes require a continuous and high power supply involving the traction unit. The new generation will be characterised by switching current-free "on" and "off" states. The significantly reduced energy demand allows the application of simpler energy storage devices leading to a selfsustaining and self-locking brake system. This analogy to classical pneumatically driven friction brakes paves the way to the desired availability. Key innovation therefore is the use of permanent magnet technology. By the application of permanent magnets the magnetic field required for braking is generated without losses in contrast to current fed and lossy coils of today's eddy current brakes. The paper presents this innovative braking technology and demonstrates the technical possibilities, resulting from the application of permanent magnets. A detailed comparison of today's eddy current brakes with the new generation of permanent magnet excited eddy current brakes will be included.

Marc Leßmann, Torsten Grunwald, Thomas Volk, Gert Fregien, Henry, Lehmann, Volker Jörg - Knorr-Bremse