A Study on Stabilities of Field Windings for Superconducting Power Generators

Abstract

Stabilities and heat flux in liquid helium in a high gravitational field up to 2, 000G at a rotating speed of 3, 600rpm, are studied to establish the fundamental design criterion of field windings of superconducting generators. It is clarified that magnet stability is greatly improved in a rotational field compared with stationary state, because of the enhancement of natural convection for the cooling of the coils caused by a high gravity. The heat transfer coefficient measured from a copper surface to liquid helium is 0.75×10⁴Wm^-2K^-1 at about 1, 000G, and it is identical to the calculated value based on the normal zone propagation velocity under the same condition.