Permanent-Magnet Motors for Flywheel Energy Storage Systems The permanent-magnet synchronous motor (PMSM) and the permanent-magnet brushless direct current (BLDC) motor are the two primary types of PM motors used in FESSs. PM motors boast advantages such as high efficiency, power density, compactness, and suitability for high-speed operations.
Energy storage systems (ESSs) can alleviate the problems associated with renewable energy power generation technology. Electrical energy storage systems (EESSs) enable the transformation of electrical energy into other forms of energy, allowing electricity to be stored and reused when needed.
Energy storage systems act as virtual power plants by quickly adding/subtracting power so that the line frequency stays constant. FESS is a promising technology in frequency regulation for many reasons. Such as it reacts almost instantly, it has a very high power to mass ratio, and it has a very long life cycle compared to Li-ion batteries.
Magnetic bearing systems are characterized by minimal losses, high efficiency, and negligible friction losses. They either require minimal power or are self-sustaining, which contributes to reduced energy loss during prolonged energy storage. The need for lubrication and sealing is eliminated with magnetic bearings.
Moreover, it boasts high temperature resistance, cost-effectiveness in manufacturing, reliability, and minimal maintenance requirements. However, its drawbacks include pronounced torque ripples, elevated noise levels, suboptimal efficiency, and notable rotor wind friction losses. 2.4.3. Permanent-Magnet Motors for Flywheel Energy Storage Systems
More recent developments include the REGEN systems . The REGEN model has been successfully applied at the Los Angeles (LA) metro subway as a Wayside Energy Storage System (WESS). It was reported that the system had saved 10 to 18% of the daily traction energy.