Improvement of the Damping Factor at Low Speed in Electrodynamic Suspension System for the JR Maglev

The electrodynamic suspension system (EDS) is one of the magnetic levitation system and has advantage of stable levitation without the gap control. However, the damping factor of the EDS system is not enough. Once the oscillation of the bogie occurs by the external disturbance, it does not converge immediately. The additional damper system is needed, so the damper coil system is installed. By the semi-active damper system, the levitation stability is improved. This paper discusses about superconducting Maglev system as application of the EDS system. Superconducting Maglev has been the magnetic levitation system developed by Central Japan Railway Company and Railway Technical Research Institute. The operation speed of the train is v = 120[m/sec]. At low speed range such as v = 60-80[m/sec], the damping factor is smaller than that of the normal operation v = 120[m/sec], and it is difficult to keep the stable levitation. In this paper, running simulation when the bogie passes large displacement at low speed is undertaken, and the improved switching method for the semi-active damper system at low speed and large displacement is discussed. From the results, to increase the period that the damper coil works. The damping factor becomes larger, and the bogie keeps the levitation. (paper)