When permanent magnet materials are successful, flywheel energy storage is on the rise!

In recent years, the energy storage track is hot, in which, lithium-ion batteries, sodium-ion batteries, flywheel energy storage, compressed air energy storage and other new energy storage technology, is updated at an unprecedented rate of iteration.

Flywheel energy storage is a kind of mechanical energy storage, with a long life, green advantages, quite popular in recent years.

The working principle of flywheel energy storage is that the flywheel is driven by electric energy and other energy to rotate, and will be converted into mechanical energy for storage, when needed, and the flywheel rotating mechanical energy stored in the form of electric energy and other forms of release.

Structure, flywheel energy storage system generally consists of five major components, including energy storage wheel body, motor, shell, power electronic system and servo system.

The energy storage wheel body determines how much energy can be stored in the flywheel storage, and there are two common types.

The first is made of alloy steel low-speed wheel body, speed is generally less than 10.000r/min, the advantage is lower cost, simple manufacturing, the disadvantage is the quality of large, high requirements of the installation site.

Second is made of carbon fibre high-speed wheel body, speed is generally greater than 10.000r/min, the advantage is the quality of light, the disadvantage is the higher cost, manufacturing difficulties.

Motor is the key to flywheel energy storage to achieve electrical energy - mechanical energy conversion. The motor suitable for flywheel energy storage needs to have four characteristics.

First, the motor is required to operate under both motor and generator conditions, and can achieve two-way conversion of electrical and mechanical energy.

Secondly, in order to ensure the long-term operation of the flywheel energy storage system and the efficiency of energy conversion, the no-load loss rate of the motor, the conversion efficiency also has high requirements; Thirdly, the normal operation of the flywheel energy storage system, the motor has four characteristics.

Third, when the flywheel energy storage system works normally, the speed range is large, and the motor needs to meet the requirements of wide speed range, simple and reliable speed regulation; Fourth, the energy density of the motor is required to be high.

Fourth, the energy density of the motor should reach a certain level, to ensure that the output torque and power.

At present, the industry believes that with the development of permanent magnet materials, permanent magnet motors have greater potential.

The flywheel shell generally includes a vacuum chamber, bearing system and heat dissipation system, etc. The main role is to ensure the safe operation of the flywheel.

The vacuum chamber can ensure that the electric power drive flywheel wheel body rotation, high speed without wind resistance; cooling system generally use air cooling and air conditioning refrigeration and other methods, mainly to avoid demagnetisation of permanent magnets, to ensure system stability; bearing system includes passive magnetic bearings and active magnetic bearings of two kinds.

The power electronic system is responsible for regulating the motor rotation, charging and discharging, which is the ‘brain’ of the flywheel energy storage.

Servo system consists of lubrication system, monitoring system, vacuum system, etc., is responsible for monitoring the flywheel operation parameters, once the parameters are abnormal, it will alarm in advance.