Test Results of a Compact Disk-Type Motor/Generator Unit With Superconducting Bearings for Flywheel Energy Storage Systems With Ultra-Low Idling Losses

摘要

A 3 kW experimental disk type permanent magnet motor/generator—designed for a superconducting flywheel energy storage system—was constructed and tested. The special design of the machine itself aimed to decrease the no-load losses so that they become equal or less than the losses of the superconducting bearing itself. To achieve this, no-load losses had to be decreased by several orders of magnitude compared to the similar losses of ordinary machines. Hence, we applied a special double-rotor, ironless stator construction, with copper windings made of Litz wire.