Vibration Suppression of HTS Maglev System Based on Negative Resistance Electromagnetic Shunt Damper

The high-temperature superconducting (HTS) maglev system has tremendous possibilities for future high-speed transportation application owing to its salient advantages of self-stable levitation and zero pollution operation. However, previous study indicated that the relatively low damping of HTS system may lead the undesired large-amplitude nonlinear vibration in system. Thus, electromagnetic shunt damper (EMSD), which usually consists of electromagnets, permanent magnets and shunt impedance connected to the terminals of the coils, is introduced in the system to improve the damping of the system. The effect of EMSD is to transfer the mechanical energy to electrical energy and consume it in the form of Joule heat. For better vibration suppression performance, this paper proposes a negative resistance electromagnetic shunt damper (NR-EMSD) in HTS maglev vehicle model. The negative resistance can offset the inherent resistance of the electromagnet coils and as a consequence, the induced current of the circuit will increase as well as the induced electromagnetic force. Also, the change of total resistance of the circuit will influence the vibration reduction performance. In this paper, the effect of NR-EMSD is tested by experiment under different working conditions compared with the model without EMSD. The results are analyzed and basic conclusions are summarized. This work may provide references for further practical application in HTS system.