What is flywheel energy storage system (fess)?

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.

What components make up a flywheel configured for electrical storage?

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.

Are flywheel energy storage systems suitable for commercial applications?

Among the different mechanical energy storage systems, the flywheel energy storage system (FESS) is considered suitable for commercial applications. An FESS, shown in Figure 1, is a spinning mass, composite or steel, secured within a vessel with very low ambient pressure.

What is a flywheel energy storage unit?

The German company Piller has launched a flywheel energy storage unit for dynamic UPS power systems, with a power of 3 MW and energy storage of 60 MJ. It uses a high-quality metal flywheel and a high-power synchronous excitation motor.

How does a flywheel energy storage system work?

The flywheel energy storage system mainly stores energy through the inertia of the high-speed rotation of the rotor. In order to fully utilize material strength to achieve higher energy storage density, rotors are increasingly operating at extremely high flange speeds.

How do different flywheel structures affect energy storage density?

Different flywheel structures have important effects on mass distribution, moment of inertia, structural stress and energy storage density. Under a certain mass, arranging the materials as far away as possible from the center of the shaft can effectively improve the energy storage density of the flywheel rotor per unit mass.