Modeling and control of a flywheel energy storage system for uninterruptible power supply

Flywheel energy storage has attracted new research attention recently in applications like power quality, regenerative braking and uninterruptible power supply (UPS). As a sustainable energy storage method, flywheel energy storage has become a direct substitute for batteries in UPS applications. Inner design of the flywheel unit is shown to illustrate the economical way to construct the system. A comprehensive model of Flywheel energy storage system (FESS) that bridging the gap caused by power outage for critical loads in commercial and industrial areas is presented. The basic circuit consists of bidirectional power converter and flywheel unit coupled with interior permanent magnet synchronous motor (IPMSM). Maximum torque per ampere (MTPA) and flux weakening are used in the control scheme on IPMSM. Detailed block diagrams of the control scheme are given. The FESS for UPS application is modeled, simulated, and analyzed in MATLAB/SIMULINK environment.