A One-Body, Laminated-Rotor Flywheel Switched Reluctance Machine for Energy Storage: Design Trade-Offs

A critical aspect of distributed generation systems focuses on the installation of Electrical Energy Storage Systems in customer-side facilities. In this scenario, flywheel technology is challenged to provide high levels of safety, compactness and competitive cost. This work presents a novel, one-body flywheel scheme based on a switched reluctance machine, whose laminated rotor fulfils both the motor/generator and energy storage functions. The one-body architecture enhances compactness and robustness, whereas the laminated rotor ensures high safety. The design of this flywheel scheme is characterised by a widely different set of trade-offs compared to conventional schemes. In order to prove the feasibility of the proposed scheme and to highlight its design trade-offs, a 60kW, 2.2kWh one-body flywheel is presented as a case study, along with some preliminary experimental results.