Efficiency Assessment of Permanent Magnet Synchronous Machines for High-Speed Flywheel Energy Storage Systems

The paper presents an accurate efficiency assessment of a novel Permanent Magnet Synchronous Machine (PMSM) to be employed in a High-Speed Flywheel Energy Storage System (HS-FESS). Particularly, the proposed machine configuration aims to minimize core losses by reducing the overall amount of steel. In this regard, some of the specific design solutions adopted are introduced and briefly discussed. Much more details are given on PMSM core losses estimation, which is carried out through an extensive Finite Element Analysis (FEA) by means of JMAG. The FEA results allow the definition of a suitable lumped-parameter electrical model of the proposed PMSM, based on which a detailed PMSM efficiency assessment can be achieved. This is particularly important for identifying the most suitable PMSM operating speed range, within which the overall HS-FESS performance can be optimized.