A detailed seminar presentation on the technology.

1. A SEMINAR ON
KINETIC
ENERGY
RECOVERY
Supervised by:
MR. M NAGARAJ SYSTEM
Prepared By:
HARSH GUPTA (KERS)
Mechanical Engineering- 5th Semester
JSSATE, NOIDA

2. CONTENTS
 KERS- INTRODUCTION
 BASIC ELEMENTS
 WORKING PRINCIPLE
 TYPES OF KERS
 ELECTRICAL KERS
 MECHANICAL KERS
 KERS IN FORMULA ONE
 CONCLUSION

3. KERS EXPLAINED
 KERS is a collection of parts which takes
some of the kinetic energy of a vehicle under
deceleration, stores this energy and then
releases this stored energy back into the drive
train of the vehicle, providing a power boost to
that vehicle.
 For the driver, it is like having two power
sources at his disposal, one of the power
sources is the engine while the other is the
stored kinetic energy.

4. WHAT IS KERS?
 The acronym KERS stands for Kinetic Energy Recovery
System.
 Kinetic energy recovery systems (KERS) store energy when
the vehicle is braking and return it when accelerating.
 During braking, energy is wasted because kinetic energy is
mostly converted into heat energy or sometimes sound
energy that is dissipated into the environment.
 Vehicles with KERS are able to harness some of this kinetic
energy and in doing so will assist in braking.
 By a touch of a button, this stored energy is converted back
into kinetic energy giving the vehicle extra boost of power.

5. BASIC ELEMENTS OF KERS
 First, a way to store and then return energy to
the power train and
 Second, a place to store this energy.
In essence a KERS systems is simple, you
need a component for generating the
power, one for storing it and another to control
it all. Thus KERS systems have three main
components: The MGU, the PCU and the
batteries/flywheel.

6. MGU (MOTOR/GENERATOR
UNIT)
 While a motor-generator set may consist of
distinct motor and generator machines coupled
together, a single unit motor-generator will have
both rotor coils of the motor and the generator
wound around a single rotor, and both coils share
the same outer field coils or magnets Working in
two modes, the MGU both creates the power for
the batteries when the car is braking, then return
the power from the batteries to add power directly
to the engine, when the KERS button is deployed.

7. PCU (Power Control Unit)
 It serves two purposes, firstly to invert &
control the switching of current from the
batteries to the MGU and secondly to monitor
the status of the individual cells with the
battery. Managing the battery is critical as the
efficiency of a pack of Li-ion cells will drop if
one cell starts to fail. A failing cell can overheat
rapidly and cause safety issues. As with all
KERS components the PCU needs cooling.

8. WORKING PRINCIPLE
 Basically, it’s working principle involves storing the energy
involved with deceleration and using it for acceleration.
That is, when a car breaks, it dissipates a lot of kinetic
energy as heat. The KERS tries to store this energy and
converts this into power, that can be used to boost
acceleration.
 A standard KERS operates by a ‘charge cycle and a ‘boost
cycle’. As the car slows for a corner, an actuator unit
captures the waste kinetic energy from the rear brakes.
This collected kinetic energy is then passed to a Central
Processing Unit (CPU) and onto the storage unit. The
storage unit are positioned centrally to minimize the impact
on the balance of the car.

10. TYPES OF KERS
 There are two basic types of KERS systems:
 Electrical
 Mechanical
 The main difference between them is in the way they
convert the energy and how that energy is stored within
the vehicle.

11. ELECTRICAL KERS
 In electrical KERS, braking rotational force is captured
by an electric motor / generator unit (MGU) mounted to
the engines crankshaft.
 This MGU takes the electrical energy that it converts
from kinetic energy and stores it in batteries. The
boost button then summons the electrical energy in the
batteries to power the MGU.
 The most difficult part in designing electrical KERS is
how to store the electrical energy. Most racing systems
use a lithium battery, which is essentially a large
mobile phone battery.

12.  Batteries become hot when charging them so
many of the KERS cars have more cooling
ducts since charging will occur multiple times
throughout a race.
 Super-capacitors can also be used to store
electrical energy instead of batteries; they run
cooler and are debatably more efficient.

13. WORKING PRINCIPLE

14. MECHANICAL KERS
 The concept of transferring the vehicle’s kinetic energy using flywheel
energy storage was postulated by physicist Richard Feynman in the
1950.
 The mechanical KERS system has a flywheel as the energy storage
device and it does away with MGUs by replacing them with a
transmission to control and transfer the energy to and from the
driveline.
 The kinetic energy of the vehicle ends up as kinetic energy of a
rotating flywheel through the use of shafts and gears.
 Unlike electrical KERS, this method of storage prevents the need to
transform energy from one type to another. Each energy conversion
in electrical KERS brings its own losses and the overall efficiency is
poor compared to mechanical storage.
 To cope with the continuous change in speed ratio between the
flywheel and road-wheels, a continuously variable transmission
(CVT) is used, which is managed by an electro-hydraulic control
system. A clutch allows disengagement of the device when not in

15.  Braking at the wheels dissipates the kinetic energy of the
vehicle that is therefore completely lost. Conversely, KERS
may store the kinetic energy of the vehicle during braking and
return it under acceleration.
 The system utilises a flywheel as the energy storage device
and a Continuously Variable Transmission (CVT) to transfer
energy to and from the driveline to the rotating flywheel.
 The transfer of the vehicle kinetic energy to the flywheel
kinetic energy reduces the speed of the vehicle and
increases the speed of the flywheel. The transfer of the
flywheel kinetic energy to the vehicle kinetic energy reduces
the speed of the flywheel and increases the speed of the
vehicle.
 The CVT is used because the ratios of vehicle and flywheel
speed are different during a braking or an acceleration event.
can change steplessly through an infinite number of
effective gear ratios between maximum and minimum values.
This contrasts with other mechanical transmissions that offer

17. ADVANTANGE OF MECHANICAL
KERS OVER ELECTRICAL KERS
 Battery-based electric hybrid systems require
a number of energy conversions each with
corresponding efficiency losses. On
reapplication of the energy to the driveline, the
global energy conversion efficiency is 31–34%.
The mechanical hybrid system storing energy
mechanically in a rotating fly wheel eliminates
the various energy conversions and provides a
global energy conversion efficiency exceeding
70%, more than twice the efficiency of an
electric system.

18. ADVANTAGES OF KERS
This potential advantages and features of this technology
in the field of automobiles are:
 High power capability
 Light weight and small size
 Long system life of upto 250,000 kms
 Completely safe
 A truly green solution
 High efficiency storage and recovery
 Low embedded carbon content
 Low cost in volume manufacture

19. KERS IN FORMULA ONE
 KERS was introduced by the International Automobile Federation (FIA) with a
view to increase overtaking during Formula One Grand Prix races, as the
boost button provides extra power. In effect, the KERS has also been used to
act as a defensive tool to block a faster car, inhibiting overtaking.
 In the 2009 season KERS was not a huge success, the system had a FIA cap
on the amount of energy that could be re-used, only 400kJ could be
stored, which when used for 6.7s per lap, the car gained some 80hp. Thus
although a 0.3s boost to lap times was achieved, the system was ultimately
limited in its potential to improve lap times.
The original CVT based Formula One KERS

20. FEATURES OF KERS IN F1
 The original Kinetic Energy Recovery System (KERS) was a small
and light device designed to meet the FIA regulations for the 2009
Formula One season.
The key system features were:
 A flywheel made of steel and carbon fibre that rotated at over
60,000 RPM inside an evacuated chamber
 The flywheel casing featured containment to avoid the escape of
any debris in the unlikely event of a flywheel failure
 The flywheel was connected to the transmission of the car on the
output side of the gearbox via several fixed ratios, a clutch and a
Continuously Variable Transmission
 60 kW power transmission in either storage or recovery
 400 kJ of usable storage (after accounting for internal losses)
 A total system weight of 25 kg
 A total packaging volume of 13 litres

21. FLYWHEEL HYBRID CARS
 A consortium led by a Jaguar Land Rover is
developing a flywheel-hybrid system that it says
boosts performance by 60 kilowatts (about 80
horsepower) while improving fuel efficiency 20
percent. Jaguar is testing its purely mechanical
flywheel system, which reportedly weighs 143
pounds, in an prototype XF sedan.
 At the 2011North American International Auto
Show Porsche unveiled a RSR variant of their
Porsche 918 concept car which uses a flywheel-
based KERS system that sits beside the driver in
the passenger compartment and boosts the dual
electric motors driving the front wheels and the
565 BHP V8 gasoline engine driving the rear to a
combined power output of 767 BHP.

22. CONCLUSION
 It’s a technology for the present and the future
because it’s environment-friendly, reduces
emissions, has a low production cost, increases
efficiency and is highly customizable and
modifiable. Adoption of a KERS may permit
regenerative braking and engine downsizing as a
means of improving efficiency and hence reducing
fuel consumption and CO2 emissions.
 The KERS have major areas of development in
power density, life, simplicity, effectiveness and
first and foremost the costs of the device.
Applications are being considered for
small, mass-production passenger cars, as well
as luxury cars, buses and trucks.

23. REFERENCE
 Wikipedia
 autosport.com
 saeindia.org
 Cross, Douglas. "Optimization of Hybrid
Kinetic Energy Recovery Systems (KERS)
for Different Racing Circuits." SAE Digital
Library. SAE International. Web. 25 Sept.
2009.
 Sorniotti, Aldo, and Massimiliano Curto.
"Racing Simulation of a Formula 1 Vehicle
with Kinetic Energy Recovery System." SAE
Digital Library. SAE International. Web. 25
Sept. 2009.