HTS flywheel from R&D to pilot energy storage system

Abstract

A 5 kWh / 250 kW engineering prototype Flywheel Energy Storage System (FESS) was designed and assembled in a joint project ATZ with L-3 Magnet- Motor Corp. The 0.6 t rotor is magnetically stabilized between a 1 ton magnetic HTS bearing on top and a new PM bearing. Based on the measured bearing load (max. 10000 N), Stiffness (3-4 kN/mm axial, 1.8 kN/mm radial) and rotor eigenfrequency (∼ 6.5 Hz) optimum operating conditions are obtained. For industrial use the flywheel periphery is described and evaluated. A comparison and evaluation showed, both the composite rotor as well the HTS magnetic bearing are utilized more efficient in systems with larger energy storage capacity. This can provide UPS function as well as power quality (load levelling) economically and correspond to industrial requirements and demands. In a third phase starting in 2009 the parameters for larger energy storage capacity 25 - 50 kWh are calculated, investigated and the basic elements studied. © 2010 IOP Publishing Ltd.