An Updated Cylindric Linear-Motor Type Flux Pump With Rapid Current Variation Capability

Abstract

In comparison to traditional DC power supplies, linear-motor type flux pumps present a number of advantages, including a reduction in dimensions, a lower cost, and decrease in energy consumption. Therefore, it is useful to use a flux pump to power superconducting magnets in a non-contact manner. In order to facilitate the rapid excitation and current modulation of superconducting magnets updated flux pump was designed to deliver a higher DC voltage output. The distribution of magnetic flux density was analyzed using COMSOL Multiphysics, which helped in determining the optimal design parameters. We extended the coupling interval of the updated flux pump to 447 mm. The updated flux pump was tested at 77 K in liquid nitrogen, with a maximum output voltage of 118.24 mV, the updated flux pump can charge an insulated (INS) double pancake coil (DPC) with 75 turns per layer to a maximum current of 88.90 A in 9 s, exceeding the critical current (${I}_{C}$) for the DPC. This updated flux pump can power superconducting rotors in superconducting motors, magnetic resonance imaging (MRI) and other devices. This study verifies that extending the coupling length can effectively increase the output voltage of flux pumps, which has far-reaching effects on the application of linear-motor type flux pumps.