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.

What type of bearing does a stationary flywheel use?

One of the few exceptions is the flywheel designed by Kinetic Traction Systems, which uses a hydrodynamic pin bearing as axial bearing. General architecture and bearing system of a stationary flywheel energy storage unit ( Active Power HD625 UPS ). (Image rights: Piller Group GmbH)

Why are bearings important for flywheel energy storage systems?

Bearings for flywheel energy storage systems (FESS) are absolutely critical, as they determine not only key performance specifications such as self-discharge and service live, but may cause even safety-critical situations in the event of failure.

What types of bearings are used in high-speed flywheel systems?

To reduce friction losses, two types of bearings are used: magnetic bearings and hybrid bearings. Magnetic bearings don’t touch the rotor or shaft, which means they have low energy losses, they last a long time and don’t need lubrication. These features make them ideal for high-speed flywheel systems.

What are the main bearing loads in an automotive flywheel energy storage system?

The main bearing loads in an automotive flywheel energy storage system are the gyroscopic reaction forces, the mass forces due to linear or angular acceleration, and the imbalance forces of the rotor.

What is a flywheel energy storage system?

Flywheel energy storage systems (FESS) are a great way to store and use energy. They work by spinning a wheel really fast to store energy, and then slowing it down to release that energy when needed. FESS are perfect for keeping the power grid steady, providing backup power and supporting renewable energy sources.