A flywheel energy storage system is an electromechanical energy conversion and storage device, which belongs to physical energy storage. The flywheel energy storage system stores kinetic energy in the form of high-speed rotation of the flywheel body, and completes the conversion between kinetic energy and electrical energy through an electric generator coaxial with the flywheel body. In layman's terms, flywheel energy storage is like a gyroscope that can store electrical energy.

Composition of flywheel energy storage device

A flywheel energy storage device is mainly composed of the following core components:

Flywheel body: The flywheel body is the core component of the energy storage system, usually made of high-strength carbon fiber composite materials to increase the limit angular velocity and reduce weight, thereby maximizing energy storage.

Bearing system: The function of the bearing system is to support the flywheel rotor, reduce friction resistance, and ensure efficient and reliable operation of the device. Common bearing types include magnetic bearings, which can significantly reduce mechanical losses.

Motor/generator: The motor/generator integrated in one component is responsible for realizing the conversion between electrical energy and mechanical energy. In the energy storage mode, the motor drives the flywheel to accelerate the rotation and convert the electrical energy into mechanical energy for storage; in the energy release mode, the motor operates as a generator and converts the stored mechanical energy back into electrical energy for use by the external load.

Power conversion device: The power conversion device is used to improve the flexibility and controllability of the system, and the output electrical energy of the flywheel energy storage system is frequency modulated, rectified or constant voltage processed to meet different load requirements.

Vacuum chamber: The vacuum chamber mainly provides a vacuum environment to reduce the wind resistance loss when the motor is running, thereby improving the efficiency of the entire system.

Working principle of flywheel energy storage

The flywheel energy storage system is an energy storage device that uses physical methods to achieve energy conversion.

During energy storage, the electrical energy is converted by the power converter to drive the motor to run, and the motor drives the flywheel to accelerate. The flywheel stores the energy in the form of kinetic energy, completing the energy storage process of converting electrical energy to mechanical energy. The energy is stored in the high-speed rotating flywheel body. After that, the motor maintains a constant speed until it receives a control signal for energy release.

When releasing energy, the high-speed rotating flywheel drives the motor to generate electricity, and the power converter outputs the current and voltage suitable for the load, completing the energy release process of converting mechanical energy into electrical energy.

The entire flywheel energy storage system realizes the input, storage and output process of electrical energy.