Simple flywheel energy storage using squirrel-cage induction machine for DC bus microgrid systems

A simple flywheel energy storage using a squirrel-cage induction machine is proposed in this paper. The suggested motor/generator system operates with an open-loop Volt/Hertz control scheme and utilizes only the nameplate data as machine parameters. Therefore complex controller tuning or machine parameter measurement is not required. Also, any communication between storage units or with other controllers is not necessary because the system uses bus voltage information for charge/discharge operations. The proposed system has an advantage on parallel operation because adding/replacing of units are straightforward. Hence it can easily operate with different types of storage or distributed energy sources in DC bus microgrid systems. Moreover, the proposed control scheme improves the overall stability of the DC bus system. The proposed system has been validated with Matlab simulation and an experimental setup is under construction for verification.