List of abrevation ………………………….. ………………………….. …………………………….. [626591]

Contents
List of abrevation ………………………….. ………………………….. ………………………….. ………………………….. ………. 3
ABSTRACT ………………………….. ………………………….. ………………………….. ………………………….. …………………. 4
INTRODUCTION ………………………….. ………………………….. ………………………….. ………………………….. …………. 5
CHAPTER I ………………………….. ………………………….. ………………………….. ………………………….. ………………… 7
1.1Regenerative Brake System ………………………….. ………………………….. ………………………….. …………….. 7
1.2 Braking performance and brake force distribution ………………………….. ………………………….. ……… 10
1.3 E -motor ………………………….. ………………………….. ………………………….. ………………………….. …………. 13
1.4 Brake energy recovery potentia l ………………………….. ………………………….. ………………………….. ……. 14
CHAPTER II ………………………….. ………………………….. ………………………….. ………………………….. ……………… 17
2. Kinetic Energy Recovery System (KERS) ………………………….. ………………………….. ………………………….. .. 17
2.1 K.E.R.S ………………………….. ………………………….. ………………………….. ………………………….. …………… 17
2.2 SYSTEM COMPONENTS ………………………….. ………………………….. ………………………….. ……………….. 18
2.2.1Elect ric Propulsion Motor/Generator ………………………….. ………………………….. ……………………. 18
2.2.2 System Control ………………………….. ………………………….. ………………………….. ……………………… 18
2.2.3 Power Control Unit (pcu) ………………………….. ………………………….. ………………………….. ……….. 19
2.2.4 Flywheel Energy Storage ………………………….. ………………………….. ………………………….. ………… 19
2.2.5 Batteries ………………………….. ………………………….. ………………………….. ………………………….. ….. 19
CHAPTER III ………………………….. ………………………….. ………………………….. ………………………….. …………….. 20
3.WORKING PRINCIPLES OF KERS ………………………….. ………………………….. ………………………….. …………… 20
3.1 Stored Energy ………………………….. ………………………….. ………………………….. ………………………….. …. 20
3.2 Charge mode ………………………….. ………………………….. ………………………….. ………………………….. ….. 20
3.3 Discharge mo de ………………………….. ………………………….. ………………………….. ………………………….. 21
CHAPTER IV ………………………….. ………………………….. ………………………….. ………………………….. …………….. 22
4 Formula One KERS ………………………….. ………………………….. ………………………….. ………………………….. 22
4.1.1 FIA KERS ………………………….. ………………………….. ………………………….. ………………………….. ….. 22
4.1.2 Drivers ………………………….. ………………………….. ………………………….. ………………………….. …….. 25
4.1.3 Safety ………………………….. ………………………….. ………………………….. ………………………….. ……… 26
4.1.4 The Electric Future ………………………….. ………………………….. ………………………….. ………………… 27
4.2 From FIA to Road Vehicles ………………………….. ………………………….. ………………………….. ……………. 27

2
4.3 Road Car Simulation ………………………….. ………………………….. ………………………….. ……………………. 29
4.4 Bus Application of KERS ………………………….. ………………………….. ………………………….. ……………….. 31
CHAP TER V ………………………….. ………………………….. ………………………….. ………………………….. ……………… 34
5 .High Power Energy Storage ………………………….. ………………………….. ………………………….. …………….. 34
5.1 Batteries ………………………….. ………………………….. ………………………….. ………………………….. ………… 35
5.2 Ultracapacitors ………………………….. ………………………….. ………………………….. ………………………….. .. 36
5.3 Flywheels ………………………….. ………………………….. ………………………….. ………………………….. ……….. 36
Conclusion ………………………….. ………………………….. ………………………….. ………………………….. ………………. 38
Bibliography ………………………….. ………………………….. ………………………….. ………………………….. ……………. 44

3
List of abrevation
1 HEV – Hybrid electric vehicle
1 ICE-Internal combustion engine
2 SM CVT – Switch -Mode Continuously Variable Transmission
3 FIA-Automotive international federation
4 KERS -Kinetic energy recovery system
5 SOC -State of charge
6 RBS – regenerative brake systems
7 CRBS -Cooperative Regenerative Braking System
8 SRBS -Superimposed Regenerative Braking System
9 EV-Electric vehicle
10 SUV -Suburban Utility vehicle
11 NEDC – New European Driving Cycle
12 PM- Permanent Magnet
13 DC-Direct current
14 AC- Alternative current
15 FES- Flywheel Energ y Storages
16 CVT -Continuously Variable Transmission
17 MGU – Motor Generator Unit
18 CAN – Controller –Area Network
19 PCU – Power Control Unit
20 NASCAR -National Association for Stock Car Auto Racing
21 BLDC -Brushless direct current
22 NEDC -New European Driving Cycle

4
ABSTRACT
Hybrid electric vehicle or (HEV) main purpose is reaching higher efficiency in energy
transmission from internal combustion engine or (ICE) to the trancion wheel of the ve hicle and
saving kinetic energ y of the vehicle ,wich is waste d as heat duri ng braking . Kinetic energy
storage cand be made via Flywheels or can be transform by the electric motor into electric
energy and stored in battery .
Flywheel is an promising system for hybrid vehicle research , offering both high energy
and power density campared to more established electric and hydraulic alternatives. Connecting
the hich sped flywheel to the relatively low speed drivetrain of the vechicle is a persistent
challenge , requiring a transmission with high variability andfficiency.
A solution is the Switch -Mode Continuously Variable Transmission or (SM CVT),
which uses a high speed clutch to transfer energy to a torsion spring in discrete pulses with a
variable duty cycle. The greatest limitation to the performance of this system is the speed a nd
efficiency of commercial clutch technology. It is the goal of this thesis to develop a novel clutch
which meets the actuation speed, controllability, and efficiency requirements of the SM CVT,
with potential for reapplication in other rotary mechanical systems with switching functionality.
The clutch demanded performance were derived via a theoretical design case based on
the performance requirements of a typical passenger vehicle,indicating the need for a very fast
engagement and disengagement.This requirements is not met at a conventional clutch. A final
concept was chosen wich employs a friction disk style ,with a normal force produced by
compressing springs via an axial cam mounted to the flywheel.
The flywheel system is also introduced in formul a one or (FIA) in 2009 with the clear
intent of directing technical developmentsin motorsport .this will have a greate impact on the key
issue of the fuel efficiency on road cars .
Hybrind and full electric vehicle main purpose is to participates at reduc ing the green
house effect and pollutant emission wich is a very studied and researched domanin.

5
INTRODUCTION

Regenerative braking is an energy recovery system wich slows a vehicle by using its
kinetic energy and converting it into electric energy wi ch can be used immediately or can be
stored and used when needed. This mechanism is used at hybrid or fully electric vehicles , this
system do not take all the responsibility from the conventional braking mechanism , it is used
only to save the kinetic ene rgy wich is lost in conventional braking mechanism, and transform it
into green energy .
This system is made of an electric motor or a flywheel (inertial mass ), gear box ,and
connecting elements between wheels and gearbox.
The system work as follows the kinetic energy of a moving vehicle is transmited to wheel
wich is rotating , wheel transmit the energy to the gearbox wich is connected to electric motor or
inertial mass and this one work as a generator wich transform the rotation motion into enectric
energy or rotational force that is stored into the flywheel .
KERS or (kinetic energy recovery system) is almost the same as conventional
regenerative braking but the kinetic energy is not transform into electric energy but is stored into
a flywheel which is rotating at high speeds , when a flux of energy is needed the flywheel
transmit its energy to a genera tor wich transform the rotation motion into electric energy wich is
transmited to the electric motor and to wheels.
The attempt to further reduce fuel consumption and CO2 emissions has created a large
interest in hybrid drive train technology. Pioneers on the hybrid market are Japanese carmakers
as Toyota and Honda who are producing hybrid cars since the mid 90s. The focus of the
European market has been on diesel technology but is currently shifting to vehicle electrification.
An important feature of hybri d drive trains is the capability to recover the kinetic energy
of the bodies translating mass that is otherwise dissipated as heat by the friction brakes. Such a
system is called a regenerative brake system (RBS). The majority of current hybrid electric
vehicles operate the traction motor as a generator, providing a brake torque to the wheels. The
energy recovery takes place by transforming this torque into electrical energy via the generator

6
that stores it in an energy storage system (e.g. battery). Brake energy recovery is limited by two
factors. The first is the state of charge (SOC) of the energy storage system. When the SOC is at
an upper charge limit, the RBS does not allow further recuperation. Second is the insufficient
amount of brake torque, provid ed by the generator, to reach high vehicle decelerations. Therefore
the RBS has to be merged with a friction brake system. As the name may presume „ electric
vehicle blended braking ‟ combines (or blends) two brake systems; a regenerative brake system
with a friction brake system. The trade -off is the proper brake force distribution to minimize
braking distance and maintaining a stable traveling direction under varying environmental
conditions, while recuperating a large as possible portion of the brake energ y. The primary
requirement of the total brake system is the brake performance, minimizing brake distance in a
stable manner. The distribution of brake torque does not only have an influence on the yaw
stability of a vehicle, but also determines how much en ergy can be recovered. The aim of the
RBS is to retain the same measure of safety while recovering the largest possible amount of
kinetic energy. The thesis aims to gain a better understanding to what extent a RBS is capable of
recovering energy and how it will affect vehicle stability. The objective is to „ find a way to
control regenerative brake torque, to obtain maximum energy recovery while maintaining
vehicle stability and maneuverability. ‟ The outcome is a proposal for control strategies and
system li mitations for the RBS in different e -motor configurations.

7
CHAPTER I

1.1REGENERATIVE BRAKE S YSTEM

A regenerative brake system (RBS) converts the kinetic energy, caused by the
deceleration of the vehicle body, into another type of energy (e.g. electric, rotational kinetic)
instead of dissipating it as heat through friction brakes. Brake energy recuperation is an
important feature of electrified vehicles and will become increasingly important in future
vehicles. In electric vehicles (EV), RBS operates as range extender and in hybrid electric
vehicles (HEV) RBS significantly reduces emissions.
A comparison of fuel savings for a luxur y SUV on the New European Driving Cycle
(NEDC). Parallel hybridization without energy recuperation promises a fuel reduction of
approximately 20% in comparison with a similar sized non -hybrid vehicle. Adding brake energy
recovery saves an additional 6% on fuel consumption. However, it must be emphasized that the
efficiency gain, due to energy recovery, is considerably higher in urban driving than normal use
on highways. This is caused by frequent moderate braking events in urban areas, which allow
full rege nerative brake exploitation .
As mentioned in previous paragraph the electric motor is unable to provide all the brake
torque necessary for large decelerations. If regenerative brake torque is only applied to one axle,
stability and maneuverability issues can occur. Therefore, regenerative braking is operated in
conjunction with a friction brake system. A frequently used name for regenerative braking is
„hybrid ‟ braking, as it obtains the total brake torque from two different sources (figure 1 ). Two
groups of regenerative brake systems (RBS) can be roughly distinguished named parallel RBS
and series RBS, or “without torque blending” and “with torque blending” [P10]. Within the
EVBB project the names Add-on (additive) braking and blended braking are used to d enote
parallel and series RBS. Bosch uses other terminology for their brake system development;
Superimposed Regenerative Braking System (SRBS) and Cooperative Regenerative Braking
System (CRBS), corresponding with parallel – and serial RBS, respectively. I n both braking

8
systems a portion of the kinetic energy is recuperated by the RBS and the remainder is dissipated
by the friction brakes. Just like vehicle propulsion the braking can be divided in three different
working stages;

 Generator (electric) braking
 Hybrid braking (Add -on or blended)
 Friction braking

A parallel RBS works „ in parallel ‟ with a friction brake system (figure 2), meaning that
the conventional brake system layout remains virtually unchanged. The brake pedal is
mechanically coupled with the brake caliper and the brake pressure is proportional to the pedal
travel and force. The electric motor (in generator mode) will add an additional brake torque. The
driver‟s brake pedal feel must be the same as a conve ntional brake system. That means, with the
same pedal input (i.e. travel and force), the total brake force of the parallel RBS should reach the
same deceleration as the conventional system [P6]. Therefore, the brake torque added by the
generator can‟t be v ery large and the recuperation potential is limited. A big advantage of
parallel RBS is that there is no requirement for brake -by-wire (chapter 1.2.4). This means the
brake control will be less sophisticated and the brake system has a high reliability. Par allel RBS
is most commonly used in mild hybrids. The parallel braking system can be applied insteadof
compression braking. The internal combustion engine (ICE) operates during compression
braking as a pumping device and can be disconnected from the drive t rain by disengaging the
clutch. The brake torque of the electric motor must equal the compression braking of the ICE,
because when the energy storage reaches the upper limit State of Charge (SOC) the clutch will
be engaged, again to use compression braking instead.
Series RBS realizes true blended braking between the friction brake system and the
generator. The aim of the series or blended brake control is, achieving a speed independent
constant deceleration for a given brake pedal position, thus „ blending ‟ regenerative torque and
friction brake torque. This is particularly important for high power generators, as they can be
used for a large portion of the requested brake torque. The regenerative brake is prioritized over
the friction brake system especiall y at low deceleration braking. When the brake pedal is further

9
or faster depressed, the brake control unit (BCU) adds friction brake torque to gain deceleration.
Strong electric generators need more modified brake systems. The brake pedal needs to be
decou pled from the brake caliper leading to a so called brake -by-wire system. The control of a
series RBS is more complex, but performs much better on optimizing energy recovery. Eshani,
Gao and Emadi [1] explain that the biggest recovery can be obtained by a f ully controllable
hybrid brake system. However, the control strategy is much more complicated than a parallel or
additive functioning brake system.

Notations
SOC State of Charge (energy
storage)
RBS Regenerative Brake System
HB Hydraulic Brake
(conventional)
EHB Electro -Hydraulic Brake
Figure 1 : parallel – and series regenerative braking scheme
Independent of the RBS type, these are the main system (brake torque) limitations:

 The brake torque is not large enough to meet t he requested brake torque during
intensive braking. Power dissipated by a front friction brake can be above 100 [kW].
 The electric motor is unable to deliver a constant brake torque in the upper speed
range. This means that the regenerative brake torque is speed dependent while the brake
torque request is not.
 At speeds around zero the brake torque of the electric motor drops to zero, due to low
motor electromotive force.
 At stand -still friction brakes are better to hold vehicle (parking or holding assist).

10
 Fail -safe function. In case the vehicle electronics malfunction the vehicle should still
be able to come to a standstill, meaning a secondary brake system will be n ecessary.
 RBS availability is limited by the charging condition of the energy storage system.
 By vehicle stability under critical driving (low friction or split -μ surfaces).

In case a battery is used as energy storage system, the RBS is not allowed to charge the
battery when the State of Charge (SOC) is at the upper limit, to prevent overcharging. The
internal resistance of the battery rises exponentially above a SOC of approximately 80% but is
relatively constant in moderate charge range [P2]. This 80% SOC is often taken as the upper
threshold of battery charge in regenerative braking control. When a parallel RBS is used a,
gradual ramp down of regenerative brake torque is required. This will give the driver time to
react on the loss of regenerative brake torque, by applying more pedal force and thereby
increasing the hydraulic brake torque instead. A series or blended control will substitute the loss
of regenerative torque with the friction brake torque. The regenerative efficiency is the portion of
brake energy, which can be recuperated by a RBS.
For micro HEVs and mild HEVs with small generator power, the available regenerative
brake deceleration is relatively small (e.g. < 1.0 m/s2). In such vehicles, the RBS may be used
without blending control. This means, the conventional hydraulic braking system with standard
vacuum booster does not need to be changed [P10].

1.2 BRAKING PERFORMANCE AND BRAKE FORCE
DISTRIBUTION

The function of the braking system is the deceleration of the vehicle in a quick and safe
manner, while the travel direction remains controllable. This paragraph describes the front -to-
rear brake force distribution for pure longitudinal deceleration. The working area of the hybrid
braking system and the flexibility of brake proportiona lity is considered. The ECE regulation No.
13H that determine the working area of brake force distribution will be explained.

11
The brake force diagram is fundamental to the design of a brake system and can be drawn
using only geometric vehicle data and weig ht distribution . The distribution of the braking forces
between the front and rear axle have an influence on:

 Stopping distance. The shortest distance is reached with optimal utilization of adhesion.
 Vehicle directional control during braking. Over -braking the front axle leads to poor steer
response.
 Vehicle stability during braking. Over -braking the rear axle leads to loss of stability.
 Durability and thermal loading of brakes. The wear reduction due regenerative braking will
have the largest impact on the strongest braked axle.
Regenerative braking system does not only have to meet the brake force requirements,
but also has to recuper ate a large as possible energy portion. The hybrid braking system uses two
sources of braking torque. Criteria for the design are:
 Large enough braking force for vehicle deceleration
 Appropriate distribution of braking forces to ensure the stability of the vehicle
 Recuperate as much energy as possible, assuring the above criteria.
The vehicle deceleration during braking can be determined using the second Newton law;
𝐹𝑏𝑟=𝑚∗𝑎𝑥
𝑎𝑥(𝑔)= 𝐹𝑏𝑟𝐹+𝐹𝑏𝑟_𝑅
𝑚∗𝑔
With:
Fbr = total brake force [N],
m = vehicle mass [kg],
ax = vehicle deceleration [m/s2],
g = gravitational acceleration [m/s2],
suffixes F&R = Front & Rear .

12
Lines of constant deceleration can be plotted on an axes bounded by the brake force on
the front axle versus the brake force on the rear axle (figure 2 ). The lines represent the brake
force distribution between the front and rear axle to achieve a certain level of normalized
deceleration (marked by labels on the lines). In this pure longitudinal case the normalized
decelerati on can also be read as the longitudinal road adhesion coefficient (μ), because the
maximum braking force, that can be applied on a wheel, equals the normal load times the
adhesion (μ) between tyre and road.

Figure2 : Lines of constant deceleration
To obtain maximum brake effectiveness, which corresponds with minimum braking
distance, the brake force should be proportional to the axle loads. During a braking event the
load of the vehicle shifts to the front (dynamic load shift), causing non -linearity of brake force
distribution for increasing deceleration. The normal axle loads can be determined by the moment
equilibrium around the vehicle axles.

13
With:
L = wheelbase [m],
Lf = CoG to front axle [m],
Lr = CoG to rea r axle ,
hcog = height CoG [m],
g = gravitational acceleration [m/s2].

1.3 E-MOTOR

The parallel hybrid vehicle has a wide variety of electric mo tor types and configurations .
None of them being the absolute best as all types of electric motors have their drawbacks. Two
pioneers on the hybrid market are Toyota with the Prius and Honda with their Insight. Both of
these hybrid vehicles use Permanent Magnet (PM) brushless DC (or synchronous AC)
motors/generators2. This type of electric motor is popular f or hybrid vehicle propulsion due to its
high specific power [kW/kg], good efficiency and low wear (no brushes). When a typical
efficiency map of a BLDC is plotted on the torque -speed axis it becomes clear that the sweet
spot of operation is in the mid -speed range at the constant power lines. For models in this thesis,
the operating efficiency of the electric motor and the conversion efficiency of the regenerative
braking torque are not taken into account.

14

Fig.3 Electric motor torque /speed graphics

1.4 BRAKE ENERGY RECOVERY POTENTIAL
The measure to which brake energy can be recovered is dependent on the motor
characteristics, drive train layout, energy storage capacity and drive train efficiencies. During a
brake event the State of Charge (SOC) will rarel y be the limiting factor for energy recuperation,
unless the vehicle is braking for a long time during descent. The main restrictions are the power
characteristic of the electric motor and the charging characteristic of the battery . For small
electric motors the br ake torque is limited . However, limitation also depends on motor rotational
speed, which is proportional to vehicle velocity. This thesis looks at the idealized case,
neglecting heat loses and conversion efficiency of regenerative braking tor que and focusing
purely on the power and energy that can be recuperated.
Figure 3 shows the wasted (thermal) power, in one of the front brakes, versus time during
a braking event with a 1500 [kg] vehicle decelerating from 100 [km/h] on a high adhesion road
surface . The heat dissipated in the brake accounts for a substantial amount of power.

15
The brake event in 5 seconds needs an average deceleration of 5.5 [m/s2] which is
considered hard braking. The figure is used for the thermal design of brake disks, ra ther than the
study of energy recovery. However, it gives a good illustration of the magnitude of power
needed during vehicle braking.

Figure 4: Thermal power dissipated in front brakes, Source: [12]
Plotting the maximal driveshaft torques generated by the 30 [kW] and 100 [kW]
electric motors on the brake fo rce distribution curve illustrates the deceleration, that can be
achieved in electric only mode. The blue area together with yellow area marks the possible
decelerations [g] with 3600 [N.m] brake torque of the 100 [kW] motor. The yellow area marks
possible decelerations with 1200 [N.m] brake torque of the 30 [kW] motor. The areas in the chart
are only valid for the constant (maximum) torque region. Above the base rotational speed of the
electric motor the torque declines, reducing the surface areas displayed in the chart. Both the
torque and rotational speed can be altered if a transmission is ad ded between the electric motor
and the driveshaft. Electric motors have an ideal torque curve compared to ICEs. They are able
to generate high torque at low rotational speeds. The ICE has a flat maximum torque in the mid
range and need a multi -gear transmi ssion to achieve good performance. Electric motors can
therefore be equipped with a single gear transmission.

16
However, their efficiency reduces outside the sweet spot of the speed range. Using for
example a CVT, the motor can be operated in the sweet spo t . Changing the ratio of the torque
allows changing area in figure 15 and smaller motors could be chosen.
The magnitude of recovered brake energy is the integral of braking power supplied by the
electric motor. This does not necessarily mean that the opti mal strategy is, to choose the biggest
possible electric motors, because the majority of braking events is of moderate nature. A typical
driving cycle has braking powers generally lower than 20 [kW]. This means a 20 [kW] motor
should be able to recover nea rly all energy, making a larger motor unnecessary for deceleration
aspects. Understanding braking energy versus braking power in a typical driving cycle, is very
helpful for power capacity design of the electric motor drive and the on -board energy storage, so
that they are capable of recovering most of the braking e nergy without oversize design .

Fig 5 Brake force range of electric motor

17
CHAPTER II

2. Kineti c Energy Recovery System (KERS)

2.1 K.E.R.S

Kinetic storages, also known as Flywheel Energy Storages (FES).
While using this technologi, flywheel (inertial mass) is accelerating to a very high rotational
speed (60.000rpm) and maintaining the energy in the system as rotational energy. The energy is
converted back by transmiting the rotational spee d to generator . Available performance comes
from moment of inertia effect and operating rotational speed.
Flywheel mass is either mechanically driven by CVT (Continuously Variable
Transmission) gear unit [Fig. 6.] or electrically driven via electric motor / generator
unit [Fig. 7.].

Fig (6) Mechanically driven composite flywheel Fig(7) Electrically driven flywheels

18

Devices that use mechanical energy are being developed, most Flywheel Energy Storages
systems use electric power to accelerate and decelerate the inertial mass .
In comparation with othe r known ways of storing electrical power (batteries and
capacitors), FES with electrically driven fly wheel systems combined with innovative concept
offer essential advantages like : full -cycle lifetime, full -cycle lifetime, independent of load,
temperature and state of charge.

2.2 SYSTEM COMPONEN TS

Fig (8)KERS components

2.2.1Electric Propulsion Motor/Generator
Also known as a MGU – Motor Generator Unit

2.2.2 System Control
System communication is provided via CAN interface (Controller –Area Network).

19
2.2.3 Power Control Unit (pcu)

Fig (9) integrated power electronics – liquid cooled Inverter.

2.2.4 Flywheel Energy Storage

Fig(10)flywheel

2.2.5 Batteries

Fig (11)Batteries pack
The components which store the electric power. For fully electric and hybrid conventional
cars this component is essential , and the technology used for fabrication of this elements is still
developing ,and is also looking for a alt ernative (super capacitor).

20
CHAPTER III

3.WORKING PRINCIPLES OF KERS

3.1 STORED ENERGY

Basic principle of kinetic energy storage is made by rotational energy. While using this
approach , inertial mass is accelerating to a very high rotational speed and maintaining the
energy in the system as rotational energy.

3.2 CHARGE MODE

Car is reducing speed during recuperative braking. Vehicle kinetic energy is transferred
to the electric motor wich generate electric power, wich send the energy to flywheel sto rage.

Fig(12) energy transfer Fig(13)

21
3.3 DISCHARGE MODE
The vehicle is accelera ting during discharge mode ,flywheel is transferring it‟s power
back to the electric motor, wich works as a propulsion motor.

Fig (14) energy transfer from flywheel fig (15)

22
CHAPTER IV

4 FORMULA ONE KERS

“March 26, 2009 The 2009 FIA Formula One World Championship starts thisweekend
with round one in Melbourne Australian where we are about to witness thebiggest number of
rule changes in the history the sport. The front and rear wingshave been significantly changed in
size and height to reduce the aerodynamic effecton cars following each other. Many of the
aerodynamic 'extras' added by teams lastseason around the side pods will be banned and after 11
years of grooved tiresslicks will make a return. The aerodynamic changes include a first in F1,
driver adjustable front wing flaps.”1

4.1.1 FIA KERS

“Although no -one in Formula One will publicly admit it, the sport has been under
pressure from the increasingly successful NASCAR where constant passing and photo finishes
are the weekly norm. The close racing in NASCAR has won huge race day crowds and global
TV audiences, bringing with it enormous financial s uccess. All the changes being made to F1
this year are in an effort to increase over taking and to reclaim the recently questionable status of
formula one as the ultimate automotive research and development series in the world.
The rule changes we're most interested in are those concerning the introduction of
the Kinetic Energy Recovery System (KERS) that will eventually make every future Formula
One race car a hybrid. KERS is not mandatory in 2009 but will be in 2010 and as a result some
teams who have no chance of challenging for the world championship have opted not to use

1 Formula One KERS explained By Paul Evans March 26, 2009

23
KERS immediately. To remain competitive in 2009, the usual race winning teams will all be
running KERS this weekend and for the full season.
The FIA rules governing KERS are fairly sim ple but very restrictive. From this
season teams are allowed to use KERS to draw 60 Kw of energy from the rear axle on the car,
which can be stored up to a total of 400kJ (111 watt hour) of energy per lap, to be reused in the
form of a 'boost' button. In e ffect the system uses regeneration to collect and store energy during
braking which allows the drivers to use 60 Kw (82 hp) for 6.6 seconds per lap. The teams are
free to choose between either mechanical or electric hybrid systems. Of the ten teams in Form ula
One, all bar one have chosen the electric hybrid system with only Williams pioneering a
flywheel mechanical system.
In fact half the teams on the grid, including front runners Ferrari and Renault, have opted to use
the Electric KERS system developed by Italian Auto electrical supplier Magnetti Marelli.
The system itself is fairly conventional, using a single 60 Kw liquid cooled brushless
direct current (BLDC) motor / generator unit, which operates at around 120 degrees C.
The motor is attached to the front of the 2.4 liter V8 and driven by a reduction gear off
the crankshaft. Also included in the system is a KERS control unit, separate from the Microsoft
supplied FIA engine control unit, with a similar operating temperature to the motor. This is
mounted low in the side pod for cooling. The battery pack is mounted at the bottom of the fuel
cell and in the case of Ferrari is supplied by French Li -ion battery maker Saft.
The teams that will run the Magnetti Marelli system in 2009 include the previous ly
mentioned Ferrari plus the team they supply motors to, Toro Rosso. Renault will run the
Magnetti Marelli system along with their satellite team Red Bull Racing.
Honda/Brawn may have possibly run Ferrari engines in 2009 in which case they would
have also used the Magnetti Marelli KERS system but the most likely engine deal now is with
Mercedes. Brawn will be supplied engines alongside McLaren and Force India and will use the
McLaren/Mercedes in -house developed KERS system. McLaren Mercedes have been worki ng
on their in -house KERS for almost two years. McLaren actually developed a KERS system in
1999. Mario Illien created a system for Mercedes in 1999 that used hydraulic fluid pressure to
recover energy lost in braking. It would have provided a 45bhp power boost for four seconds but
could have been used many times per lap. The system developed by McLaren in Cconjunction
with Mercedes for the 2009 season is an electrical based hybrid system.

24
BMW started KERS development with Forschung und Technik GmbH, which is a 100%
BMW owned research and technology arm, in mid -2007 and have announced their system 'race
ready'. BMW tested a range of different solutions and analyzed electric, mechanical, hydr aulic
and even pneumatic systems. After several months of research, it was clear that only an electric
system would deliver the required energy, while at the sam e time combining maximum safety
and, above all, the lowest possible weight. In the BMW KERS system the batteries are housed in
the side pods for cooling and the co ntrol unit is fitted in the right hand side pod.
Williams have decided to take on the task of being the only team in the field to develop a
flywheel system and to do so without the resources of a major manufacturer behind them.
Williams will run Toyota eng ines, but more on Toyota in a moment. They acquired of a minority
shareholding in Automotive Hybrid Power Limited, a company developing high -energy
composite flywheels for use in energy recovery systems. The Williams Hybrid Power system
will use a flywheel spinning at up to 40,000 rpm. It has been reported that the flywheel systems
is still being bench tested and has not been track tested as yet. This may result in Williams not
debuting their KERS until Round 7 of the 2009 world championship which takes pla ce in Turkey
in early June.
That only leaves Toyota, the company who started the move to hybrids beginning in
1998. Toyota have decided not to race with KERS in Melbourne and it is possible that Toyota
will not use a KERS system at any time during the 2009 race season. It is already known that the
Cologne based team will contest the season opening Australian Grand Prix without the energy
re-use technology, despite the TF109 being fitted with a functioning KERS during testing.
Toyota have been quoted as sayi ng they think KERS is 'primitive' and not relevant to road car
Hybrid systems.
Toyota say they have already had success with a more advanced hybrid system in their
Supra HV -R with which they won the Tokashi 24 hour race by 9 laps over second place. The
technical difference between the two systems is enormous. While KERS is limited to 60kw for
6.6 seconds per lap and can only be used on the rear axle, the Toyota HV -R system has a 150 kw
electric motor on the rear axle plus two 10 kw wheel motors on the front wheels. As 70% of all
braking effort is on the front wheels the Toyota system can collect a lot more energy per lap.

25
The FIA rules will grant Toyota their wish of four wheel regeneration but they will have
to wait until 2013. The KERS regulations will al low the energy storage limit to be doubled to
800kj (222 wh) by 2011, and KERS will be allowed on both axles with up to 200kW and 1.6MJ
(444 wh) of energy storage per lap from 2013.
Toyota have admitted they came very close to following Honda out of Formul a One
at the end of last year and there have been reports that Toyota have ambitions to race their
Hybrid at Le Mans. With Hybrid rules being introduced to Le Mans this year and flywheel
systems being banned, if the regulations allow four wheel hybrid syst ems then that may prove
too tempting. Toyota last raced in Le Mans in 1999 and placed second and may now hope a
hybrid race car will take them to victory.
The Peugeot team are taking advantage of the new Le Mans hybrid rules and have
incorporated the Magne tti Marelli hybrid system into their 908 HY V12 diesel sportsprototype.
The Peugeot will have 60kw (80 hp) for up to 20 seconds per lap. ”2

4.1.2 Drivers

“The KERS system adds an extra 30kg (66 lb) weight to the car which effects weight
distribution and tire wear. The minimum weight of 605kg stipulated for the cars in the
regulations includes the driver. The difference between the actual weight and minimum weight is
leveled out by positioning ballast around the car to optimum effect. Traditionally, this m eans that
a heavier driver has been at a disadvantage as he has had less ballast to balance out the car. Using
KERS will further reduce – by the weight of the system – the amount of ballast available. In
order to prevent F1 from becoming even more of a joc keys' competition some teams such as
BMW are pushing for an increase of the minimum weight in the future. Many drivers have
reported putting extra effort into reducing their weight, although it must be said they are all very
light to start with.

2 Formula One KERS explained By Paul Evans March 26, 2009

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The driv ers will be kept especially busy in the cockpit this year learning how best to
use the new systems. With KERS having only 111 watt hours of energy storage capacity and all
of the energy coming from the rear axle under braking, there may be more than a few exciting
moments where mid way through a heavy braking zone, as the battery becomes full, the rear
brake balance will suddenly change perhaps resulting in the odd spin or two.
An added distraction is the driver adjustable front wing which many have specula ted
will be used at the exact same time as the KERS boost button to momentarily reduce drag during
a passing maneuver. ”3

4.1.3 Safety

“Most Formula One cars in 2009 will be wearing “High Voltage” warning stickers for the
first time. Insulated gloves and color -coding will help keep F1 marshals safe from the dangers of
new KERS technology while Puma have developed a new insulated shoe for drivers. The cars
will also carry a KERS status warning light so it should be clear to a marshal who walks up to
the car that if the status light is in the wrong state, he shouldn‟t touch the car.
In July 2008 a mechanic received a powerful shock after touching the steering wheel and
side pod of a BMW F1 car fitted with the KERS prototype. After six weeks of investigation, the
team determined that the shock was due to a high -frequency AC voltage between the two contact
points, the cause of which was traced back to the KERS control unit and a sporadic capacitive
coupling from the high -voltage network to the 12 -volt network. T he voltage ran through the
wiring of the 12 -volt network to the steering wheel and through the carbon chassis back to the
control unit. The analysis, in addition to identifying the problem and pointing to solutions,
resulted in other recommendations for th e development of electric KERS systems. Among the
measures arrived at are changes in the design of the control unit to avoid capacitive coupling
effects, extended monitoring functions for high frequencies and a conductive connection of the
chassis componen ts to avoid any electric potential. ”4

3 Formula One KERS explained By Paul Evans March 26, 2009
4 http://www.gizmag.com/formula -one-kers/11324/

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4.1.4 The Electric Future

The FIA must be congratulated for being the first motorsport sanctioning body in the
world to introduce hybrid systems to a professional racing series. It did take them a while to
wake up to the fact that having teams spending so much time in wind tunnels meant that the
winning teams had to own one or two of their own, a factor that had become increasing irrelevant
to any kind of road car application. Now with the emphasis squarely on putting the best and
brightest to work on developing electric hybrid tech nology we can most definitely look forward
to seeing what effect the red hot competition of Formula One racing can do for EV technology:
McLaren , Ferrari , Renault ,BMW , Williams , Toyota , Force India”

4.2 FROM FIA TO ROAD VEHICLES

Flywheel energy storage system for passenger cars are not a new notion, var ious system
have been previously developed like a flywheel kinetic energy storage system in a bus in 1980‟s.
Flywheel system most notably the containment of the rotating mass and the method of con trol
and transmission of the energy to and from the inertial mass, wich have inhibited development
and mainstream application. The formla one has successfully started technical development in
these areas resulting in technical solution to the previous vie wed issues
Flywheel system efficiency is a important area where the mechanical hybrid system
excels ove the electric hybrid . Electric hybrid system based on battery require a number of
energy conversion , each have a corresponding losses of efficiency . On reapplication of the
energy to the driveline, the energy conversion are repeated and from there are more losses f
energy . From this transformation result a circa of 31% to 34% round trip efficiency.
The hybrid system with mechanical action stores the recovered energy in a inertial mass
(flywheel) hence eliminating the various energy transformation and providing a far more
efficient system. Measured trip efficiencies for a mechanical system over 70%,resulst a system
twice as efficient as an electric on e.

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The fist developing stage of a mechanical hybrid specification for a conventional
automotice application is to predict the potential fuel consumption reduction for a target
application. Criteria number including quality of energy storage , the power t ransfer rate, ration
range of the system , can be optimized to calculate the maximum benefit to the vehicle.
The flywhell operating speed,the Formula one high speed/low mass and inertial mass
operating from 32.250 to 64.500, or a lower speed and higher m ass and inertial mass can be
utilized.the final specification of the flywheel for a mechanical hybrid system will depend upon a
numerous factors includind package space , energy storage requiremens , weight , vacuum
requirements and containment system spec ification..
The F1 KERS full toroidal variator of a 55 mm roller diameter with a ration of 6:1 has
been used. The F1 rules limits the power at 60kw .

However, whereas the Variator in the F1 application can be used as a simple CVT with
the ratio spread of 2 on the flywheel and 3 on the vehicle speed, for mainstream automotive
applications the ratio spread requires extension. Assuming an operating range of the engine
of 6 (1000 to 6000 rpm) and a flywheel ratio of 2, a total ratio spread of 12 is requir ed. This is
achieved by incorporating the variator into a mechanical shunt with a simple epicyclic gearset
of basic ratio of 4.7 with :
• The Sun gear is connected to the engine and variator input
• The Annulus is connected to the variator output
• The Pla net Carrier is connected to the flywheel drive.

29

Fig (16) Assumed Driveline Layout

4.3 ROAD CAR SIMULATION

Regardint to the New European Driving Cycle (NEDC) is that the relatively low vehicle
speeds and gentle acceleration and decelerations together with considerable time spent with the
vechicle stationary and the engine at idle speed . Even trough the engine little power during these
phase , it absorbs considerable energy overcoming its inherent motoring losses.
In figure 6 compares the energy dissi pated by the engine overcoming its internal losses with the
energy dissipated by the vehicle completing the NEDC cycle.

30

Fig 17 NEDC -energy comparison with and without the flywheel system

The first data (engine only) represent the energy balance for conventional non -hybrid
driveline.
The second data show the energy saved by addition of regenerative braking drived from
the flywheel and the effect of switching the engine of when not needed.
Addition of flywheel reduce the energy dissipated by the engin e resulting in a saving of
20%.

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Fig 18 Flywheel speed over the NEDC Cycle
Converting from energy saving to fuel saving result a 30.2% fuel economy improvement.

4.4 BUS APPLICATION OF K ERS
The city busses represent the best possible application of KERS principal.
High mass relatively low rolling resistance due to low moving speed and consistent start and
stop operation provides the gratest regenerative braking potential .
The system was been applied to a 8500kg and 30 seat city bus wich was driven by a
110kw (150 hp) diesel engine with a five speed automatic transmission using a torque convertor
as a engine coupling. The inertial mass systems speed range has been retained ar 12000 -24000
rpm, but the flywheel inetia has been inceased to 0.323kg*m^2 to enagle storage of the kinetic
energy of the bus when deceleration from 50 km/h.
In fact the simulation shows a maximum stored energy equivalent to 75% of this value
implying only 600 kj capacity to be adequate.

32
The reduce diesel engine speed range 500 -2500 rpm provides the opportunity to reduce
the overall ratio spread of the variator shunt 9:1with a consequent reduction in reciculating
power 1.07of the transmitted power.
The most significant difference between the bus study and the road car study is the
presence
of the torque convertor. Typical bus operation does not apply the lockup clutch until third
gear. The resulting degradation in driveline efficiency would effectively prevent flywheel
charge in the first two gears. However the flywheel acts as a constant power source at any
transmission input speed. Fluid coupling torque multiplication is not therefore required. The
transmission shift schedule is therefore modified to lock the convertor when possible and
when operating on the flywheel at all con ditions other than launch in first gear .
Given the power capacity of the flywheel and the inherent torque control of the Variator,
this will neither reduce vehicle performance nor degrade driveline smoothness.
As for the road car application, it is essenti al to reduce parasitic fuel consumption by
moderating engine operation while the flywheel drives. However the ancillary load for a large
passenger vehicle is likely to be significant and must include a pneumatic load for brakes and
suspension as well as ai r conditioning or heating. Engine drive of the ancillary load has
therefore been assumed at all times. Flywheel operation will therefore disconnect the engine
from the driveline but keep it operating at or near idle speed.

Fiq 18 KERS Bus cycle

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The energ y comparison plot shows that, unlike the road car application, the engine
motoring loss of 15 MJ is significantly less than the energy supplied to the vehicle (26.5 MJ).
Hence the energy saving due to energy recovery is significant at 36%.

Fig 19 Energ y Comparison With & Without The Flywheel Hybrid System

Fig 20 Flywheel Speed Over the bus cycle

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CHAPTER V

5 .HIGH POWER ENERGY S TORAGE

Some energy storage applications require high peak power output but for only a short
amount of time, so the total amount of energy required is small. One example is in hybrid
electric vehicles, where a high power electrical energy storage system is used to augment the
power of an internal combustion engine (ICE) during rapid acceleration and to recover energy
during r egenerative braking. The use of this transient energy storage system improves the
efficiency of the ICE by allowing it to run at more efficient operating points. Although the peak
power during acceleration 2 and braking can be quite high, the time period f or full -power
acceleration and braking is only on the order of 10‟s of seconds, and thus requires only a modest
amount of energy storage.
A second example is in power quality applications. Many sensitive industrial process
can be severely impacted by momen tary voltage sags or outages. Examples include data centers,
semiconductor production, and paper production. In these instances, even a very short outage can
cause hours of downtime and production loss. It has been estimated that over 80% of utility
power probl ems last less than 1 second , so an energy storage system capable of supplying power
for only a few seconds can greatly reduce the frequency and resulting damage from these power
quality problems.
Both these applications share the characteristic of high peak power requirements with
only modest energy storage requirements. The question is“What type of energy storage
technology is best suited for this type of applications?” The term “best suited” assumes that the
minimum requirements for the applicatio n are met, and usually refers to some balance between
“lightest weight,” “smallest volume,” or “least expensive.”
The notion of “least expensive” can be determined by comparing the $/kW and $/kW ·
hr parameters for each technology (which ideally should inc lude maintenance, disposal, and
other life -cycle costs). Four basic performance parameters can be used determine to gauge the
other three facets of “best suited.”

35
The first four performance parameters to consider are the specific power ( W/kg ), power
densi ty (W/l), specific energy ( W · hr/kg ), and energy density ( W · hr/l).
The terms “gravimetric power/energy density” and “volumetric power/energy density” are also
used, but the first set of terms will be used here. Obviously, there are many other important
factors to consider, such as efficiency, reliability, or speed of response, but these basic
performance parameters provide a good starting point.
In the high power energy storage applications under consideration here, the limiting
factor on improved perfor mance is often the ability to meet the peak power requirement for the
application. For these applications, a higher specific power, a higher power density, or lower
$/kW would improve performance more than higher specific energy, higher power density, or
lower $/kW · hr. Improved performance could mean anything from a more mileage efficient car
to a smaller power quality solution.

5.1 BATTERIES

Currently, batteries are by far the most widely used technology for these applications.
The most commonly used batteries are lead -acid and nickel metal -hydride (NiMH) type
batteries.
Lead -acid batteries are often used in stationary applications such as back up power
supplies where low cost is most important, and NiMH batteries are the most widely used for
hybrid el ectric vehicles because of their higher specific power, higher power density, and longer
lifetime.
The Honda Civic Hybrid, Honda Insight, and Toyota Prius all use NiMH batteries.
There are several drawbacks to using batteries in high power applications, however.
Since batteries have lower specific and volumetric power densities than the other technologies,
they result in a heavier and larger system. Batteries also have lower efficiencies at high power
levels, and can suffer from reduced lifetime under the se conditions as well.

36
5.2 ULTRACAPACITORS

Ultracapacitors operate similarly to normal capacitors, storing energy by separating
charge with a very thin dielectric. The difference is that ultracapacitors have much higher surface
area densities, allowing them to store much more energy. As a result, ultracapacitors have a
higher power densities and high power efficiencies than batteries.
Ultracapacitors are not widely used commercially for high power applications, although
they are often used as a n alternative to a battery backup system in consumer electronics to
provide short term backup power.
Although they are a promising technology, they are still expensive, have an unproven
lifetime, and have a more limited temperature range than flywheels. U ltracapacitors also tend to
have a large series resistance which imposes a large time constant and thus slower response time.

5.3 FLYWHEELS

Flywheel energy storage systems operate by storing energy mechanically in a rotating
flywheel. Electrical energy i s stored by using a motor which spins the flywheel, thus converting
the electric energy into mechanical energy. To recover the energy, the same motor is used to
slow the flywheel down, converting the mechanical energy back into to electrical energy.
Flywhe els have higher power densities, higher efficiency, longer lifetime and a wider operating
temperature range than batteries. Although flywheels have lower energy densities than batteries,
their energy density is high enough to meet the requirements for many high power applications
and still realize performance benefits over batteries.
There are two basic classes of flywheels based on the material used in the rotor. The first
class uses a rotor made up of an advanced composite material such as carbon -fiber or graphite.
These materials have very high strength to weight ratios, which give flywheels the potential
ofhaving high specific energy. The second class of flywheels uses steel as the main structural
material in the rotor.

37
This class includes traditional f lywheel designs which have large diameters, rotate
slowly, and low power and energy densities, but also includes some newer high performance
flywheels as well, such as the on e made by Activepower, Inc. and the one presented in this
thesis. The flywheel in this thesis is an integrated flywheel, which means that the energy storage
accumulator and the electromagnetic rotor are combined in a single -piece solid steel rotor. By
using an integrated design, the energy storage density of a high power steel rotor fl ywheel energy
storage system can approach that of a composite rotor system, but avoid the cost and technical
difficulties associated with a composite rotor.

Battery

Supercapacitor

38
Conclusion

Regenerative braking is a very promising system rega rding to automotive engineering ,
this mechanism can easily transform almost all the loses of a conventional brake system , it can
transform up to 70% of a vehicle kinetic energy w hich otherwise is lost in friction and heat in
brake system.
Kinetic energy recovery system can transform and store the energy into battery, inertial
mass or super capacitor and the reuse it to put the vehicle in motion or as in the case of formula
one cars it can be transformed into a boost of energy to increase the speed of the vehicle in a
certain moment and for a short period of time . KERS system is one with the biggest potential ,
is charging in the moment of progressive speed reduction and and all the energy is stored into a
inertial mass w hich is rotating with speed around 12-25000 rotation per minute , and have
minimum loses with friction into the compartment of the inertial mass.
The discharge moment is chose by the driver , this system nowadays is more often met into
formula one cars , because of some reglementation w hich impose internal combustion engine
cylinder size to be reduced ,this reglementation is also called downsizing of the engine .
The maximum power of KERS system is also limited to 60 kw , this rule is also appli ed
for safety of the driver , and the possibi lity of controlling the vehicle . Downsizing of the engine
is applied to reduce as much as possible the pollution of atmosphere, w hich nowadays is a very
important fact because of the greenhouse effect .
In my study I also mentioned the components of a re generative braking , th is system is
easy to implement b ecause almost all the components needed is used to built the hybrid electric
vehicle , the electric motor w hich is the one of the main components , battery w hich give the
electric power needed by the m otor , transmission w hich transmit the power from the electric
motor to the wheel , this is a conventional system met at hybrid electric vehicle and electric one,
all that this system do , is reverse the power is not coming from the engine but is coming fr om
the fact that the car is an object w hich is moving with a certain speed , and the driver decide to
reduce the speed of the car and not to lose the kinetic energy of vehicle is activating the
recovery sy stem and the car weight is rotati ng the wheel w hich transmits its velocity back to the

39
transmission and back to the electric motor w hich is working as a generator and the electric
power produced is sent to battery and stored .
The energy stored into battery can be used by the electric motor to put the v ehicle in
motion.
The other solution of regenerative braking is KERS system or(kinetic energy recovery
system ) w hich work pretty much the same as a conventional one , but in this case the recovered
energy is stored into a inertial mass w hich is rotating with some speed around 25 000 revolution
per minute , this ine rtial mass is pu tted into a box or support in w hich the minimum loses of
power is minimum , almost like in a vacuum chamber where all the friction with air and other
this is negligible , the ro tating force of the inertial mass is the send back to the electric motor
which use it to boost the car when the driver need it.
The city busses represent the best possible application of KERS principal,
high mass relatively low rolling resistance due to low moving speed and consistent start and
stop operation provides the greatest regenerative braking potential.
KERS system with inertial mass is very used in motorsport cars because of its low weight
and the possibility of a very fast discharge w hich is needed to boss very quick the vehicle and to
achieve high speed , but for normal electric vehicle is a little bit more weight added to the total
mass , is also helping th e vehicle when it‟s start and saved a little bit of energy w hich is not
taken from the battery but is taken from the inertial mass, for a car w hich function almost all the
time inside a town I think that this system can be take out of the equation .
Normal regenerative braking doesn‟t have that much potential , it save only around 30%
of the energy of the vehicle and transform it into electric power .
But the conventional hybrid car also have loses of energy into connecting wire which make
around them magnet ic field , and so some electric p ower is lost .
As in the case of our university electric vehicle into a road trip of around 30 km in w hich
half of the road is climbing and the rest is descending , with the help of regenerative braking it
was able to recover around 3% of the battery capac ity.
Another solution used into hybrid cars is super capacitor which can store electric energy
and can transmit it to the electric motor very fast, but it also have loses of energy into electric
wire wich connect the electric motor to the capacitor.

40
My hom e made hybrid vehicle use a conventional energy recovery system wich store the
energy into a battery , I u sed a normal electric motor with a small torque reducing so that the
electric motor to be able to move the vehicle.

In conclusion for me it was a very interesting subject and I am very glad that I chose to
study more extensive this system .
In my opinion hybrid electric vehicle and electric vehicle are a very promising branch
into automotive engineering and can do a lot of good to the entire enviro nment , just because use
a green energy which is freely given to us by the eath and we should use it very wise and take
care of our mother nature .
Just simply using electric vehicle which have a pollution number 0 , we can help our
environment to heal a nd so we can leave a healthier life .
Regenerative braking is also contributing to energy saving, even right now the fuel
reduction is very low , if we take into consideration this system is helping our life , this mean
we have to give less money for fo ssil fuel , for electric energy , this mean that we can save our
money to do other thing , to have a much happier life and to enjoy our time , we will not run that
much over money .
Electric vehicle with Regenerative Braking are the future of our civilization .

41

Hybrid cars

42

KERS

43

44
Bibliography

1- ENERGY SAVING AND ENVIRONMENT FRIENDLY TECHNOLOGY OF
HYBRID -ELECTRIC VEHICLE WITH NEW POWER TRANSMISSION AND
ENERGY RECUPERATION APPROACH( Cundev Dobri1, Mindl Pavel2
Faculty of Electrical Engineering, University “Goce Delcev” – Stip, Republic of
Macedonia 1 ,Department of Electric Drives and Traction, Faculty of Electrical
Engineering, Czech Technical University in Prague, Czech Rep ublic 2)
2- Electric Vehicle Blended Braking maximizing energy recovery while
maintaining vehicle stability and maneuverability.
( Master’s Thesis in Chalmers’ Automotive Engineering and in European Master
of Automotive Engineering)

3- Mechanical Hybrid system comprising a flywheel and CVT for Motorsport &
mainstream Automotive applications(Douglas Cross ,Flybrid Systems LLP ,Chris
Brockbank Torotrak (Development) Ltd)

4- Magneti Marelli supplies electric engines for the LaFerrari, Maranello‟s first
hybrid car

5- Formula One KERS(By Paul Evans March 26, 2009 )

6- Full-Toroidal Variable Drive Transmission Systems in Mechanical Hybrid
Systems – From Formula 1 to Road Vehicles (Chris Brockbank BSc (Hons) & Chris
Greenwood BSc (Hons) )

45
7- Design and Prototyping of a Low -Speed Flywheel System for Automotive
Brake Energy Recover (Sheng Xu)

8- Design of a High Speed Clutch with Mechanical Pulse -Width Control( Jessy
Cusack 2/6/2013)

9- KINETIC ENERGY RECOVERY SYSTEM BY MEANS OF FLYWHEEL
ENERGY STORAGE(Cibulka, J.)

10- An Integrated Flywheel Energy Storage System with a Homopolar Inductor
Motor/Generator and High -Frequency Drive( Perry I -Pei Tsao)

11- An Integrated Flywheel Energy Stora ge System with a Homopolar Inductor
Motor/Generator and High -Frequency Drive( Perry I -Pei Tsao)