Working principle of rotating energy storage motor

How does a flywheel energy storage system work?

Flywheel Energy Storage Systems (FESS) rely on a mechanical working principle: An electric motor is used to spin a rotor of high inertia up to 20,000-50,000 rpm. Electrical energy is thus converted to kinetic energy for storage. For discharging, the motor acts as a generator, braking the rotor to produce electricity.

What is electromechanical storage system?

electromechanical storage system in which energy is stored in the kinetic energy of a rotating mass. Flywheel systems are composed of various materials including those with steel flywheel rotors and resin/glass or resin/carbon-fiber composite rotors.

What is the kinetic energy stored in the rotor?

The total kinetic energy stored in the rotor can be expressed as 2 where Izz is the rotational mass moment of inertia. It was assumed that the rotation of the flywheel is purely about the z-axis with a rotational velocity ω. with the masses mj, the rotor height h and the constant density ̺j of each rim.

Can a single-material flywheel rotor increase energy storage capacity?

Ha et al. (1998) optimized the design of a single-material multi-rim flywheel rotor with interferences and different fiber angle in each rim. They were able to increase the energy storage capacity by a factor of 2.4 compared to a rotor without interferences and purely circumferentially wound fibers.

How kinetic energy is stored in a flywheel?

Electric energy is supplied into flywheel energy storage systems (FESS) and stored as kinetic energy. Kinetic energy is defined as the “energy of motion,” in this situation, the motion of a rotating mass known as a rotor, rotates in a near-frictionless environment.

How much energy does a rotor store?

At 6400 rpm, each of the four rotors will store 121 MJ (34 kWh). In 45 seconds, they can store 122 MJ (34 kWh) and release it in 2–3 seconds. The flywheel energy densities are 28 kJ/kg (8 Wh/kg), omitting the torque frame, and 18.1 kJ/kg (5 Wh/kg) with the stators and casings.