Contributions in the magnetic energy storage devices shielding and energy confinement

A magnetic energy storage system made in an ellipsoidal enclosure and associated variable height superconductive coils is analysed and a comparison with other systems possessing the same superconductive material volume V_{s} and operating current I is performed. Two sets of geometrical dimensions are proposed, one associated with V_{s} =0.01 m ^{3} and I=80 A and the other corresponding to V_{s} = 1.437 m ^{3} and I=540 A. An efficiency evaluation dependency W_{m}/V_{S} −V _{Threshold}/V_{Overall} , taking into account the safety magnetic field threshold B_{Threshold} =0.5 mT distance, is introduced. The results show a remarkable improvement achieved with the ellipsoidal structure in terms of stored energy as well as better shielding in respect to the equivalent system solenoid.