1) A flywheel energy storage system consists of five main components: a flywheel, motor/generator, power electronics, magnetic bearings, and external inductor. 2) Flywheels store energy mechanically in the form of kinetic energy by rotating a steel or composite mass at high speeds. 3) Permanent magnet motors/generators are most suitable as they provide higher efficiency and smaller size compared to other types.

1. Flywheel Energy Storage
System
Name Harshal Bhatt
Department Mechanical 1st year

2. Introduction
A flywheel, in essence is a mechanical battery - simply a
mass rotating about an axis.
Flywheels store energy mechanically in the form of kinetic
energy.
Flywheels are one of the most promising technologies for
replacing conventional lead acid batteries as energy storage
systems.

3. Components
 There are five mainly five components in flywheel
energy storage system:
1) Flywheel
2) Motor/Generator
3) Power Electronics
4) Magnetic bearings
5) External Inductor

4. Flywheel
Flywheels store energy in a rotating mass of steel of
composite material.
Mechanical inertia is the basis of this storage
method.
Use of a motor/generator, energy can be cycled
(absorbed and then discharged)
Increasing surface speed of flywheel, energy storage
capacity (kWh) of unit increased.

5. Motor/Generator
Permanent Magnet (PM) machines have the most advantages,
including higher efficiency and smaller size when compared with
other types of motors/generators of the same power rating.
PM also exhibit lower rotor losses and lower winding
inductances, which make it more suitable for a vacuum
operating environment and the rapid energy transfer of flywheel
applications.
The motor/generator is designed to be operated at high speed for
minimize system size.

6. Power Electronics
Flywheel energy storage system is the three-phase
IGBT-based PWM inverter/rectifier.
The IGBT is a solid-states device with ability to
handle voltages up to 6.7 kV, currents up to 1.2 kA and
most important high switching frequencies.

7. Magnetic Bearings
Magnetic bearings consists of permanent magnets, which
support the weight of the Flywheel by repelling forces, and
electromagnets are used to stabilize the Flywheel.
The best performing bearing is the high-temperature super-
conducting (HTS) magnetic bearing, which can situate the
Flywheel automatically without need of electricity or
positioning control system.
HTS magnets require cryogenic cooling by liquid nitrogen.

8. External Inductor
The high-speed PM machines offer low inductances with
low number of stator turns and large operating magnetic air
gaps .
The low inductances result in High Total Harmonic
Distortion (THD) which increases the machine power losses
and temperature.
Using an external inductor in series with the machine in
charging mode is necessary to reduce the THD and bring it
within an accepted range.

9. Future work
 Advanced flywheel system rotate above 20,000 rpm in vacuum
enclosure made from high strength carbon composite filament will be
very efficient.
The flywheels are not the primary source of power generation.
Rather, when there is too much power on the grid, it is shunted to
the flywheel facility and used to set the flywheels in motion.
Then, when the power is needed a few seconds or minutes later, the
momentum of the flywheels is used to generate power back into the
grid.

10. Conclusions
The state of charge can easily be measured, since it is given
by the rotational velocity
 The fast rotation of Flywheel rotors is suitable for direct
generation of high voltage.
 Environmental friendly materials, low environmental
impact.

11. Some Pictures Of Flywheel
Energy Storage System

14. Thank you for your time....