Flywheel Energy Storage System (FESS) is an electromechanical energy storage system which can exchange electrical power with the electric network. It consists of an electrical machine, back-to-back converter, DC link capacitor and a massive disk.
Their efficiency is high during energy storage and energy transfer (>90 %). The performance of flywheel energy storage systems operating in magnetic bearing and vacuum is high. Flywheel energy storage systems have a long working life if periodically maintained (>25 years).
Fig. 7.8 shows the integration of the flywheel energy storage system with the grid. In this method the stored energy is transferred to the grid by a generator, alternative current (AC)/direct current (DC) rectifier circuit, and DC/AC inverter circuit. Figure 7.8. Flywheel energy storage system topology.
In 1999 , the University of Texas at Austin developed a 7-ring interference assembled composite material flywheel energy storage system and provided a stress distribution calculation method for the flywheel energy storage system.
The major components that make up a flywheel configured for electrical storage are systems comprising of a mechanical part, the flywheel rotor, bearings assembly and casing, and the electric drive part, inclusive of motor-generator and power electronics.
Prof. Dr.-Ing. Günter Keller references including diagrams, figures and sketches. ... The input energy for a Flywheel energy storage system is usually drawn from an electrical source coming from the grid or any other source of electrical energy.