Flywheel energy storage (FES) works by accelerating a rotor () to a very high speed and maintaining the energy in the system as. When energy is extracted from the system, the flywheel's rotational speed is reduced as a consequence of the principle of ; adding energy to the system correspondingly results in an increase in the speed of th.
Many storage technologies have been developed in an attempt to store the extra AC power for later use. Among these technologies, the Flywheel Energy Storage (FES) system has emerged as one of the best options. This paper presents a conceptual study and illustrations of FES units.
What is a flywheel energy storage system (fess)?
According to Al-Diab (2011) the flywheel energy storage system (FESS) could be exploited beneficially in dealing with many technical issues that appear regularly in distribution grids such as voltage support, grid frequency support, power quality improvement and unbalanced load compensation.
What is a magnetic bearing in a flywheel energy storage system?
In simple terms, a magnetic bearing uses permanent magnets to lift the flywheel and controlled electromagnets to keep the flywheel rotor steady. This stability needs a sophisticated control system with costly sensors. There are three types of magnetic bearings in a Flywheel Energy Storage System (FESS): passive, active, and superconducting.
How to connect flywheel energy storage system (fess) to an AC grid?
To connect the Flywheel Energy Storage System (FESS) to an AC grid, another bi-directional converter is necessary. This converter can be single-stage (AC-DC) or double-stage (AC-DC-AC). The power electronic interface has a high power capability, high switching frequency, and high efficiency.
What is a flywheel system?
Flywheel systems are composed of various materials including those with steel flywheel rotors and resin/glass or resin/carbon-fiber composite rotors. Flywheels store rotational kinetic energy in the form of a spinning cylinder or disc, then use this stored kinetic energy to regenerate electricity at a later time.
A 30 MW flywheel grid system started operating in China in 2024. Flywheels may be used to store energy generated by wind turbines during off-peak periods or during high wind speeds. In 2010, Beacon Power began testing of their Smart Energy 25 (Gen 4) flywheel energy storage system at a wind farm in Tehachapi, California.