Numerical Analysis of Amplitude Reduction Using Electromagnetic Shunt Damper with an LCR Parallel Circuit in a Superconducting Magnetic Levitation System

Abstract

An electromagnetic shunt damper is a type of a dynamic vibration absorber; however, the subsystem consists of an LCR series circuit instead of a supporting mass. When this is utilized to a superconductive levitation system, the optimal value of the resistance within the circuit is quite small. The value is difficult to be precise in practice, hence there are chances that the damper will be ineffective. However, there are possibilities that the restriction due to the optimal resistance value can be eased by using an LCR circuit where the resistance and the capacitance is parallel. In this study, the authors studied the vibration characteristics of a levitating magnet with an electromagnetic damper. The theoretical frequency responses of the amplitude were derived for both conditions: the system with a series circuit and a parallel circuit. Numerical calculations were also performed to confirm the effectiveness of the damper.