Insulation design of pool-boiling He-cooled superconducting coils. Coil parameters affecting insulation spacing [SMES application]

An insulation design procedure for SC (superconducting) coils for electric power apparatus is proposed and applied to a small scale SMES (superconducting magnetic energy storage system) consisting of two modules of pool-boiling helium-cooled SC coils. Coil operation parameters affecting insulation spaces are discussed on the basis of an estimated time-dependent ratio of insulation withstand voltage to induced voltage for different quenching states according to the proposed procedure.