Evaluation on thermal loss of superconducting coil caused by levitation control in superconducting-hybrid magnetic levitation system for high-speed Maglev

In superconducting-hybrid electromagnet (SH-EM) used for the large-gap electromagnetic suspension (EMS) system, superconducting coil is affected by the control current of suspension system because it is magnetically linked with a pair of control coil. This paper deals with thermal loss characteristics of superconducting coil caused by levitation control in large-gap EMS system. The thermal losses are experimentally evaluated with a prototype SH-EM fabricated for this study. Results show that the thermal loss is generated in the SH-EM when the control coil is activated by a time-varying form of current. And the loss generated by the operation of the control coil has the characteristics of dependency on the amplitude and frequency of the control current. The value increases as the control current and frequency increases. And the loss is also dependent upon the levitation gap, but it becomes less as the levitation gap Increases.