23291564 regenerative braking system (1)

7/31/2019 23291564 Regenerative Braking System (1)

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A

SEMINAR REPORT ON

REGENERATIVE BRAKING SYSTEM

SUBMITTED BY: GUIDED BY: -

ACKNOWLEDGEMENT

T h i s a c k n o w l ed g e m e n t i s a h u m b le a t t e mp t t o e a r n e st l y t h a n k a l l

t h o s e w h o w e r e d i r e c t l y o r i n d i r e c t l y i n v o l v e d i n p r e p a r a t i o n o f t h i s

s emi na r r epor t .

I n p a r t i c u l a r I a m t h a n k f u l t o m y g u i d e M r . K a l p e s h D . M a n i a

w h o g u i d e m e i n m y s e m i n a r w o r k . I a m t h a n k f u l t o h i m f o r t a k i n g

a c t i v e p a r t i n t h e p r e p a r a ti o n o f m y s e m i n a r r e p o r t. I t w a s i m p o s si b l e

t o p r es en t t h i s r epor t w i t hou t h i s co - oper a t i on and s ugges t i on .


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L as t b ut n ot l ea st I w ou ld l ik e t o e xp re ss o ut d ee p s en se o f

g ra ti tu de t o a ll t he f ac ul ty m em be rs o f M ec ha ni ca l E ng in ee ri ng

Depar t men t and a l s o my f r i ends who he l p me t o accompl i s h wha t I have

s t a r t ed f o r .

DEPARTMENT OF MECHANICAL ENGINEERING

THE SEMINAR REPORT ON :

REGENERATIVE BRAKING SYSTEM

PREPARED BY:

GUIDED BY:

EXAMINER H.O.D


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(1) ___________________

(2) ___________________

(3) ___________________

(4) ___________________

ABSTRACT

R e g e n e r a t i v e B r a k i n g S y s t e m i s t h e w a y o f s l o w i n g v e h i c l e b y u s i n g

t h e m o to r s a s b r a ke s . I n st e ad o f t h e s u rp l us e n e r gy o f t h e v e h i c le

b e in g w as ted a s unwan ted h ea t , th e mo to r s ac t a s gen e ra t o r s and r e tu rn

s ome o f i t t o t he o ve r head wi r es a s e l ec t r i c i t y .

T h e v e h i c l e i s p r i m a r i ly p o w e r ed f r o m t h e e l e c tr i c a l e n e r g y g e n e r a t e d

f r o m t h e g e ne r a t or , w h i c h b u r ns g a s o l in e . T h i s e n er g y i s s t o re d i n a

l a r g e b a t t e ry , a n d u s e d b y a n e l e c tr i c m o t o r t h a t p r o v i d e s m o t i v e f o r c e

t o t h e w h e e ls . T h e r e g e n er a t i ve b a r k i n g t a ki n g p l a c e o n t he v e h i c l e i s

a w a y t o o b t a i n m o r e e f f i c i e n c y ; i n s t e a d o f c o n v e r t i n g k i n e t i c e n e r g y

t o t h e r m a l e n e r g y t h r o u g h f r i c t i on a l b r a k i n g , t h e v e h i c le c a n c o n v e r t a

g o o d f r a c ti o n o f i t s k i n e ti c e n er g y b a c k i n to c h a rg e i n t h e b a t t er y ,

us i ng t he s ame p r i nc i p l e a s an a l t e r na t o r .


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LIST OF FIGURES

F ig . 1 Gr aph i ca l r ep r es en t a t i on o f ene r gy us age be t ween t wo veh i c l e s.

F ig . 2 Mer cur y Hybr i d Mar i ne r

F ig . 3 Regener a t i ve Br ak i ng Sys t em Us i ng Ni t i no l Spr i ng .


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CONTENTS

1. INTRODUCTION

2. NECESSITY OF THE SYSTEM

3. REGENRATIVE BRAKE

4. ELEMENTS OF THE SYSTEM

5. DESCRIPTION & OPERATION

6. RESULTS

7. CONCLUSION


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CHAPTER 1: INTRODUCTION

Brake: -

A br ake i s a mach i ne e l emen t and i t s p r i nc i p l e ob j ec t i s t o abs o r b

e n er g y d u ri ng d ec el er at io n. I n v e h ic le b ra ke s a r e u se d t o a b so rb

k i n e t i c e n e r g y w h e r e a s i n h o i s t s o r e l e v a t o r s b r a k e s a r e a l s o u s e d t o

a bs or b p ot en ti al e ne rg y. B y c on ne ct in g t he m ov in g m em be r t o

s ta ti on ar y f ra me , n o rm al ly b ra ke c o nv e rt s k in et ic e n er gy t o h ea t

e n e r g y. T h i s c a u se s w a s t ag e o f e n e r g y a n d a ls o w e a r i ng o f f r i c ti o n a l

l i n i ng ma t e r i a l .

Regenerat ive Braking System:-

R e g e n e r a t i v e B r a k i n g S y s t e m i s t h e w a y o f s l o w i n g v e h i c l e b y

u si ng t he m ot or s a s b r a ke s. I ns te ad o f t h e s u rp lu s e n e rg y o f t he

v e h i c l e b e i n g w a s t e d a s u n w a n t e d h e a t , t h e m o t o r s a c t a s g e n e r a t o r s

and r e t u r n s ome o f i t t o t he ove r head wi r es a s e l ec t r i c i t y .T h e v e h i c l e i s p r i m a r i ly p o w e r ed f r o m t h e e l e c tr i c a l e n e r g y g e n e r a t e d

f r o m t h e g e ne r a t or , w h i c h b u r ns g a s o l in e . T h i s e n er g y i s s t o re d i n a

l a r g e b a t t e ry , a n d u s e d b y a n e l e c tr i c m o t o r t h a t p r o v i d e s m o t i v e f o r c e

t o t h e w h e e ls . T h e r e g e n er a t i ve b a r k i n g t a ki n g p l a c e o n t he v e h i c l e i s

a w a y t o o b t a i n m o r e e f f i c i e n c y ; i n s t e a d o f c o n v e r t i n g k i n e t i c e n e r g y


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t o t h e r m a l e n e r g y t h r o u g h f r i c t i on a l b r a k i n g , t h e v e h i c le c a n c o n v e r t a

g o o d f r a c ti o n o f i t s k i n e ti c e n er g y b a c k i n to c h a rg e i n t h e b a t t er y ,

us i ng t he s ame p r i nc i p l e a s an a l t e r na t o r .

T h e r e f o r e , i f y o u d r i v e l o n g d i s t a n c e w i t h o u t b r a k i n g , y o u l l b e

p ower ing the veh i c le en t i r e l y f rom ga so l in e . The r egener a t i ve b r ak in g

R e g e n e r a t i v e B r a k i n g S y s t e m c o m e s i n t o i t s o w n w h e n y o u r e d r i v i n g

i n t he c i t y , and s pend i ng a good dea l o f your t i me b r ak i ng .

You wi l l s t i l l u s e mor e f ue l i n t he c i t y f o r each mi l e you d r i ve t han on

t h e h i gh w ay , t h ou g h . ( T he r mo d yn a m ic s t e ll s u s t h at a l l i n ef f ic i en c y

c o m e s f r o m h e a t g e n e r a t i o n . F o r i n s t a n c e , w h e n y o u b r a k e , t h e b r a k e

p eda l s hea t up and a qua n t i t y o f hea t , o r ene r g y, i s l o s t to th e ou t s ide

wor l d . F r i c t i on i n t he eng i ne p r oduces hea t i n t he s ame way.

Hea t ene r gy , a l s o , has h i ghe r en t r opy t han , s ay , e l ec t r i c , mean i ng t ha t

i t i s l e s s o r de r ed . )

Def in i t ion:

B r a k in g m e t h o d i n w h i c h t h e m e c h a n i ca l e n e r g y f r o m t h e l o a d i s

c o n v e rt e d i n t o e l e c tr i c e n e r g y a n d r e g e n er a t e d b a c k i n t o t h e l i n e

i s k n ow n a s R eg en er at iv e B ra ki ng . T he M ot or o pe ra te s a s

gener a t o r .

Regenerat ive Braking For Hybrid Vehic le :

I n m o s t e l e c t r i c a n d h y b r i d e l e c t r i c v e h i c l e s o n t h e r o a d t o d a y ,

t h i s i s a c c o m p l i s h e d b y o p e r a t i n g t h e t r a c t i o n m o t o r a s a g e n e r a t o r ,

p ro v id i ng b rak i ng t o rq ue t o th e whee l s a nd r echa r g i ng the t r a c t io n

b a t t e r i e s . Th e ene r gy p ro v ide d by reg ener a t i v e b rak ing can t hen b e

us ed f o r p r opu l s i on o r t o power veh i c l e acces s o r i e s .


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CHAPTER 2:NECESSITY OF THE SYSTEM

T h e r e g e n er a t i ve b r a k i ng s y s te m d e l i v er s a n u m b e r o f s i g n if i c a n t

advan t ages ove r a ca r t ha t on l y has f r i c t i on b r akes . I n l ow- s peed , s t op -

a n d - g o t r a f f i c w h e r e l i t t l e d e c e l e r a t i o n i s r e q u i r e d ; t h e r e g e n e r a t i v e

b rak ing s ys t em can p ro v id e t he ma j o r i t y o f t he to t a l b rak ing f o rc e .

Th i s vas t l y i mpr oves f ue l economy wi t h a veh i c l e , and f u r t he r enhances

t he a t t ra c ti ve ne ss o f v eh ic le s u si ng r eg en e ra t iv e b ra ki ng f or c i t y

d r i v i ng . A t h i ghe r s peeds , t oo , r egener a t i ve b r ak i ng has been s hown t o

con t r i bu t e t o i mpr oved f ue l economy by a s much as 20 %.

Cons i de r a heavy l oaded t r uck hav i ng ve r y f ew s t ops on t he r oad .

I t i s ope r a t ed nea r max i mum eng i ne e f f i c i ency . The 80% of t he ene r gy

p ro duced i s u t i l i z ed to o ve r come the r o l l ing a nd ae r od yn ami c ro ad

f o rc e s. T h e en e rg y w as t ed i n ap p l yi n g b ra k e is a b ou t 2 %. A l so i ts

b rak e spec i f i c f ue l cons ump t i on i s 5 %.

Now co ns ide r a veh ic le , wh ich i s op e ra t ed in t he ma in c i t y wh ere

t r a f fi c i s a m a j o r p r ob l e m h e re o n e h a s t o a p p l y b ra k e f r e q ue n t l y. F o r

s u c h v e h i cl e s t h e w a st a ge o f e n er g y b y a p p li c a ti o n o f b r a k e i s a b o ut

6 0 % t o 6 5 % . A nd a ls o i t i s i ne ff ic ie n t a s i t s b r ak e s p ec if ic f ue l

cons umpt i on i s h i gh .

HEAVY LOADED TRUCK CITY BUS

2.1 Graphical representation of energy usage between two vehicles.

Road 80%

Other

18%

Rake 65%

Road

26%

Brake 2% other 9%


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S ome of th e ad va nta ges o f re ge ne rat ive b raki ng o ve r

convent ional braking are as fo l lows:

Energy Conservat ion:

The f l ywhee l abs o r bs ene r gy when b r ak i ng v i a a c l u t ch s ys t em s l owi ngt he ca r down and s peed i ng up t he whee l . To acce l e r a t e , ano t he r c l u t ch

s ys t em connec t s t he f l ywhee l t o t he d r i ve t r a i n , s peed i ng u p t he ca r and

s l o w in g d o w n t h e f l yw h e e l . E n e r g y i s th e r e f or e c o n s e r ve d r a t h e r th a n

w as te d a s h ea t a nd l ig ht w hi ch i s w ha t n or ma ll y h ap pe ns i n t he

con t empor a r y s hoe / d i s c s ys t em.

Wear Reduct ion:

A n e l ec t ri c d r iv e t ra i n a l so a l lo w s f o r r e ge n e ra t iv e b r ea k in g w h ic h

i nc re as es E ff ic ie n cy a nd r ed uc e s w e ar o n t h e v eh ic le b ra k es . I n

r e g e n e r a t i v e r a k i n g , w h e n t h e m o t o r i s n o t r e c e i v i n g p o w e r f r o m t h e

b a t t e r y pack , i t r e s i s t s the t u r n in g o f the w hee l s , ca p tu r in g some o f the

e n e r g y o f m o t i o n a s i f i t w e r e a g e n e r a to r a n d r e t u r n i n g t h a t e n e r g y t o

t h e b a t te r y p a c k . I n m e c h an i c a l b r ak e s ; l e ss e n i n g w ea r a n d e x t en d i n g

b rak e l i f e i s no t p oss i b le . Th i s r ed uces th e us e o f us e t he b r ake .

Fuel Consumpt ion:

T h e f u el c o ns u mp t io n o f t h e c o n ve n ti o na l v e h ic l es a n d r e ge n er a ti v e

b rak ing s ys tem ve h ic l e s was ev a lu a ted ove r a cou rs e o f va r ious f i xed

ur ban d r i v i ng s chedu l es . The r e s u l t s a r e compar ed as s hown i n f i gu r e .

R e pr es en ti ng t he s ig n if ic an t c o st s ay in g t o i ts o wn e r, i t h a s b ee n

p ro ved th e r egener a t i v e b r ak in g i s ve r y f ue l -e f f i c i en t .

Braking i s not to ta l loss :

C o nv en ti on al b ra k es a pp ly f ri ct io n t o c on v er t a v eh ic le s k in et ic

e n e r g y i n t o h e a t . I n e n e r g y t e r m s , t h e r e f o r e , b r a k i n g i s a t o t a l l o s s :

o n c e h e a t i s g en e r a t ed , i t i s v e r y d if f i c ul t t o r e u s e. T h e r e g e ne r a t iv e

b rak ing s ys te m, howev er , s l ows a v eh ic le dow n in a d i f f e ren t way.


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CHAPTER 3 :REGENERATIVE BRAKING SYSTEM.

A regenerative brake is an apparatus, a device or system which allows a vehicle to

recapture and store part of the kinetic energy that would otherwise be 'lost' to heat when

braking.

The IMA operating principle

Honda ' s pa tented IMA con cept i s qui t e s imple - use an ef f i c i ent Ot to

engine supplemented by an e lec t r i c motor when addi t ional power i sneeded. Also refer red to as a ' hybr id ' sys tem because i t uses two power

sources , the IMA concept a l lows the Civ ic Hybr id to use a smal ler

gasol ine engine wi thout any s igni f i cant los s in per formance .

Thi s sys tem i s especia l ly ef fec t ive due to the f ac t tha t a cce lera t ionrequi res a s igni f i cant ly h igher power than needed for c ru i s ing on a l evel

road (where vehic les spend mos t of the i r t ime) . An engine more

power fu l than needed has to work under low load mos t of the t ime,condi t ion where i t s e f f i c i ency i s lower than under h igh loads , thus

worsening the vehic le ' s fue l economy. .
http://en.wikipedia.org/wiki/Vehiclehttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Heathttp://en.wikipedia.org/wiki/Brakehttp://en.wikipedia.org/wiki/Vehiclehttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Heathttp://en.wikipedia.org/wiki/Brake


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The e lec t r i c motor -genera tor pos i t ioned between the engine and

t ransmiss ion ass i s t s the engine when accelera t ing and recovers energy to

s tore in ba t t e r i es when braking or decelera t ing ( regenera t ive braking) ,a l lowing i t to opera te independent ly wi thout the need for a gr id power

supply .

When the Civic Hybr id i s coas t ing or i t s brakes are app l i ed , i t s e l ec t r i c

motor becomes a genera tor , conver t ing forward momentum (kine t i cene r gy) i n t o e l ec t r i ca l ene r gy , i n s t ead o f was t i ng i t a s hea t du r i ng

conven t i ona l b r ak i ng . Ener gy i s s t o r ed i n a ba t t e r y pack l oca t ed beh i nd

t he r ea r s ea t i n t he t r unk . I f t he s t a t e o f cha r ge o f t he ba t t e r i e s i s l ow,t he mot o r - gene r a t o r w i l l a l s o r echa r ge t hem whi l e t he C i v i c Hybr i d i s

c r u i s i ng .


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CHAPTER 4: ELEMENTS OF THE SYSTEM

T h e re a r e t h re e b a si c e l em e nt r e qu i re d w h ic h a r e n e c e s sa r y f o r t h e

wor k i ng o f r egener a t i ve b r ak i ng s ys t em, t hes e a r e :

1 .Energy Storage Uni t (ESU):

The ESU pe r f o r ms t wo p r i mar y f unc t i ons

1 .TO r ecover & s t o r e b r ak i ng ene r gy

2 . TO abs or b exces s eng i ne ene r gy dur i ng l i gh t l oad ope r a t i on

The s e l ec t i on c r i t e r i a f o r an e f f ec t i ve ene r gy s t o r age i nc l udes

1 . H i gh s pec i f i c ene r gy s t o r age dens i t y

2 . H i gh ene r gy t r ans f e r r a t e

3 . Smal l s pace r equ i r emen tT h e e n e r g y r e c a p t u r e d b y r e g e n e r a t i v e b r a k i n g m i g h t b e s t o r e d i n o n e

o f t hre e d ev ic es : a n e le ct ro ch emi ca l b at t er y, a f l yw he el , in a

r egener a t i ve f ue l ce l l .

Regen and Bat ter ies :

Wi t h t h i s s ys t em, t he e l ec t r i c mot o r o f a ca r becomes a gene r a t o r when

t h e b r a k e p e d a l i s a p p l i e d . T h e k i n e t i c e n e r g y o f t h e c a r i s u s e d t o

g e n e r a t e e l e c t r i c i t y t h a t i s t h e n u s e d t o r e c h a r g e t h e b a t t e r i e s . W i t h

t h i s s ys t em, t r ad i t i ona l f r i c t i on b r akes mus t a l s o be us ed t o ens ur e t ha t

t h e c a r s l o w s d o w n a s m u c h a s n e c e s s a r y . T h u s , n o t a l l o f t h e k i n e t i c

e n e r g y o f t h e c a r c a n b e h a r n e s s ed f o r t h e b a t t e ri e s b e c a u s e s o m e o f i t

i s " l o s t " t o w a s t e h e a t . S o m e e n e r g y i s a l s o l o s t t o r e s i s t a n c e a s t h e

e n e rg y t r av e ls f r om t h e w h e e l a n d a x le , t h ro u g h t h e d r iv e tr a in a n d

e l e c t ri c m o t o r , a n d i n t o t h e b a t t e r y. F o r e x a m p l e , t h e T o y o t a P r i u s c a non l y r ecap t u r e abou t 30% of t he veh i c l e s k i ne t i c ene r gy .

The Honda I ns i gh t i s ano t he r veh i c l e i n add i t i on t o t he P r i us t ha t i s on

t he mar ke t and cu r r en t l y us es r egener a t i ve b r ak i ng . I n t he I ns i gh t t he r e

a r e t wo dece l e r a t i on modes : When t he t h r o t t l e i s engaged , bu t t he b r ake


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p eda l i s no t , the veh ic l e s lows down g r adua l l y, and the ba t t e r y r ece i ves

a pa r t i a l cha r ge .

W h e n t h e b r a k e p e d a l i s d e p r e s s e d , t h e b a t t e r y r e c e i v e s a h i g h e r

c ha rg e, w hi ch s lo w s t he v eh ic le d ow n f as te r . T he f ur th er t he

b r ake ped a l i s depr esse d , th e mor e t he c onve n t i ona l f r i c t i on

b r akes a r e emplo ye d .

I n t h e I n si g ht , t h e m o to r /g e n er a to r p r od u c es A C , w h ic h i s c o n ve r te d

i n t o DC, whi ch i s t hen us ed t o cha r ge t he Ba t t e r y Modul e . The I ns i gh t ,

a s w el l a s a ll o th er r eg en er at iv e s ys te ms , m us t h av e a n e le ct ri c

con t r o l l e r t ha t r egu l a t e s how much cha r ge t he ba t t e r y r ece i ves and how

much t he f r i c t i on b r akes a r e us ed .

Regen and Flywhee ls :

I n t h i s s y s t e m , t h e t r a n s l a t i o n a l e n e r g y o f t h e v e h i c l e i s t r a n s f e r r e d

i n t o r o t a t io n a l e n e r g y i n t h e f l y w h e e l, w h i c h s t o r es t h e e n e r g y u n t i l i t

i s n ee d ed t o a c ce le r at e t he v e hi cl e. T he b en e fi t o f u si ng f ly wh ee l

t echno l ogy i s t ha t mor e o f t he f o r war d i ne r t i a l ene r gy o f t he ca r can be

c a p t u r e d t h a n i n b a t t e r i e s , b e c a u s e t h e f l y w h e e l c a n b e e n g a g e d e v e n

d u r in g r e la t iv e l y s h or t i n te r va l s o f b r ak i ng a n d a c c el e ra t io n . I n t h e

c a s e o f b a t t e r i e s , t h e y a r e n o t a b l e t o a c c e p t c h a r g e a t t h e s e r a p i d

i n t e r v a l s , a n d t h u s m o r e e n e r g y i s l o s t t o f r i c t i o n . A n o t h e r a d v a n t a g e

o f f l y w h e e l t e c h n o l o g y i s t h a t t h e a d d i t i o n a l p o w e r s u p p l i e d b y t h e

f ly wh ee l d ur in g a cc el e ra t i on s ub st an ti al ly s up pl e me n ts t he p ow er

ou t pu t o f t he s ma l l eng i ne t ha t hybr i d veh i c l e s a r e equ i pped wi t h .


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2 . Cont inuous ly Var iable Transmiss ion (CVT):

T h e e n e r g y s t o r a g e u n i t r e q u i r e s a t r a n s m i s s i o n t h a t c a n h a n d l e

t o r q u e a n d s p e e d d e m a n d s i n a s t e e p l e s m a n n e r a n d s m o o t h l y c o n t r o l

e n er g y f lo w t o a n d f ro m t h e v e h ic le w he el s. F o r t h e f l yw h ee l t h e

c o nt in uo u sl y v a ri ab le t ra ns mi ss io n a nd v eh ic le b ec a us e f ly wh e el

r o t a t i ona l s peed i nc r eas es when veh i c l e s peed dec r eas es and v i ce ve r s a .

F l yw h e el c a n w o rk w e ll w i th e i th e r m e ch a n ic a l o r h y dr o st a ti c

con t i nuous l y va r i ab l e t r ans mi s s i on .

3 . Contro l Sys tem :

An ON- OFF eng i ne con t r o l s ys t em i s us ed . Tha t means tha t t he

e n gi ne i s ON u n ti l t he e ne rg y s to ra ge u ni t h as b ee n r ea c he d t he

d e s i r e d c h a r g e c a p a c i t y a n d t h e n i s d e c o u p l e d a n d s t o p p e d u n t i l t h e

ene r gy s t o r age un i t cha r ge f a l l be l ow i t s mi n i mum r equ i r emen t .


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CHAPTER5: DESCRIPTION & OPERATION

How regenerat ive braking sys tem works?

R e ge ne ra ti v e ( or D yn a mi c B ra ki ng ) o c cu rs w he n t he v eh ic le i s i n

m ot io n , s u ch a s c o a st in g , t r av e li ng d ow n hi ll o r b r a ki ng . A nd t he

a c c e l e ra t o r p e d al i s n o t b e i ng d e p r e s se d . D u r i n g R eg e n t , t he m o t o r

b eco mes a gen e ra t o r a nd s ends ene r g y bac k to the b a t t e r i e s .

I t i s e x p l a i n e d a s f o l l o w s , b e c a u s e t h e w h e e l s o f a d e c e l e r a t i n g

v e h i c le a r e s t i ll m o v i n g f o r w a r d , t h e y c a n b e m a d e t o t u r n t h e e l e c t ri c

m ot or , w hi ch t he n f e e ds e ne rg y t o t he b at te ri e s f o r s t or ag e. T h e

s y s t e m b e c o m e s , i n e f f e c t , a g e n e r a t o r , w h i c h p r o v i d e s b r a k i n g f o r c e

w h il e i t c o n ve r ts t h e v e h ic l e s k i ne t ic e n e rg y i n to a r e us a bl e f o rm -

e l ec t r i ca l ene r gy .

W h e n t h e a c c e l e r a t o r p e d a l i s r e l e a s e d , t h e a b s e n c e o f p r e s s u r e

t r i gge r s a r e s pons e f r om t he Ener gy S t o r age Uni t ( ESU) . Regener a t i ve

b rak ing beg ins , and th e ba t t e r i e s a r e r e - cha r ged by the mo to r , w h ich i s

t u r n e d b y t h e w h e e l s. I n t h i s c a s e , t h e f r i c t i on b r a k e s a r e n o t e n g a g e d .

I f m or e v ig o ro u s d ec e le ra t i on i s r eq ui re d , a n d t he b ra ke p e da l i s

d e p re s se d , t h is e n g a g e s b o th s e t s o f b r a k e s. H o we v e r, t o m a xi m iz e

ener gy e f f i c i ency , i t i s advan t ageous t o app l y t he r egener a t i ve b r ake a ss uch as pos s i b l e i t t he r e f o r e t ends t o do mor e o f i t s t o t a l wor k i n t he

f i r s t pa r t o f t he b r ak i ng mot i on .

Ther e a r e t wo dece l e r a t i on modes :

1 . F oo t o ff th ro tt l e b ut n ot o n b ra ke p ed al in th is mo de , th e

cha r ge / as s i s t gauge wi l l s how pa r t i a l cha r ge , and t he veh i c l e w i l l s l ow

down g r adua l l y .


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2 . F o o t o n b r a k e p e d a l - I n t h i s m o d e , a h i g h e r a m o u n t o f r e g e n e r at i o n

w i l l b e a l lo w e d , a n d t h e v e hi c l e w i ll s l o w m o re r a p i d l y. D u r in g l i g h t

b rak e peda l ap p l i ca t i on , on l y the I MA motor / /g ene r a to r i s s l owin g the

c a r . W i t h h ea v i e r b ra k e p e d a l a pp l i c at i o n , t h e c on v e n t io n a l f r ic t i o n

b rak es a l so co me i n to p l a y. Wh en dece l e ra t ing , r egene ra t ion wi l l

c o n t i nu e u 8 n t i l e ng i n e s p e ed f a l l s t o a bo u t 1 0 0 0 r p m. A t t h i s p oi n t ,

t he d r i ve r w i l l t yp i ca l l y s h i f t i n t o neu t r a l .


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EXAMPLE

Mercury Hybrid Mariner

1 . M e rc u r y M a r in e r H y br i d

Pr oduc t i on Pu l l ahead : P r oduc t i on beg i ns a yea r

ahead o f s chedu l e

Gr owi ng t he Mer cur y Br and : New mode l s and goa l s

Di s t i nc t i ve Des i gn : Mar i ne r f ea t u r es c l ean l i nes , ca r e f u lc r a f t s mans h i p

Power P l ay : Fu l l - hybr i d gas o l i ne and e l ec t r i c power t r a i n

Dynami c Chas s i s : N i mbl e hand l i ng and a s moot h , qu i e t r i de

Di s t i ngu i s hed Sa f e t y : Fu l l a r r ay o f s a f e t y f ea t u r es

Gr een Mi s s i on : For d Mot or Company ' s s t r a t egy f o r s us t a i nab i l i t yi n veh i c l e s

The Mer cur y Mar i ne r Hybr i d o f f e r s a un i que l y s a t i s f y i ng t r ans por t a t i on

cho i ce f o r an eve r - i nc r eas i ng s egment o f t he popu l a t i on conce r ned

abou t t he env i r onment . I t ' s a s t y l i s h , ups ca l e s por t - u t i l i t y veh i c l e w i t hn i mbl e hand l i ng and i mpr es s i ve pe r f o r mance , a s we l l a s ampl e ca r go

and t owi ng capac i t y . I n add i t i on , i t ' s an env i r onment a l l y cons c i ous

SUV wi t h r emar kab l e f ue l economy an e s t i ma t ed 33 mi l e s pe r ga l l on( mpg) c i t y , 29 mpg h i ghway and i s expec t ed t o mee t t he c l eanes t

emi s s i ons r a t i ng ach i evab l e by a f os s i l - f ue l veh i c l e ( Ca l i f o r n i a ' s

Advanced Techno l ogy Pa r t i a l Ze r o Emi s s i ons Veh i c l e s t andar d ) .
http://63.74.120.214/adclick.php?n=abc876dfhttp://www.americancarfans.com/news.cfm/newsid/2050211.012/pageview/photo/photo/1/page/1/lang/eng/mercury/1.html


18/27

Engi nee r s p l aced t he add i t i ona l hybr i d power t r a i n componen t s l ow and

t o t he r ea r , t o l ower t he cen t e r o f g r av i t y and i mpr ove t he conven t i ona l

Mar i ne r ' s f r on t - r ea r we i gh t d i s t r i bu t i on .

The r ack- and- p i n i on s t ee r i ng i s e l ec t r i ca l l y a s s i s t ed , r a t he r t han us i ng

t he t r ad i t i ona l hydr au l i c s t ee r i ng pump f o r cons i s t en t s t ee r i ng e f f o r t sand con t r o l whe t he r t he gas o l i ne eng i ne i s s t opped o r r unn i ng .

Regener a t i ve b r ak i ng us es t he t r ac t i on mot o r t o a s s i s t t he f our - whee ld i s c b r akes i n s l owi ng Mar i ne r Hybr i d whi l e s i mul t aneous l y gene r a t i ng

e l ec t r i c i t y f o r cha r g i ng t he ba t t e r y .

Regenerat ive braking o f Toyota Pr ius :

T o y o ta r e a l iz e d t h a t o n e w a y t o a c h i e ve l o n g e r v e h i c le r a n g e w a s

t o c o n s e r v e a n d r e u s e s o m e o f t h e e n e r g y t h a t a v e h i c le n o r m a l l y l o s e s

as hea t caus ed by b r ak i ng f r i c t i on . Th i s i dea l ed eng i nee r s t o app l y t he

p r i nc ip le s o f r eg ener a t iv e b rak ing .

I n a l l T oy ot a v eh ic le s t ha t f ea tu re t he r eg en e ra ti ve b ra k in g

s y st e m, t h e r e g e n er a ti v e b r a k e i s o n l y r e sp o ns i bl e f o r a p a rt o f t h e

d e c e l e ra t i o n n e c e ss a r y t o s t op t h e v e h i c le . I n a n E V , t h i s f ra c t i on i s

d e te r mi ne d b y t he v e hi cl e s s p e ed w he n b ra k in g i s i n i t ia te d . T h e

r e m a i n i n g b r a k i n g f o r c e i s p r o v i d e d b y t h e v e h i c l e s f r i c t i o n b r a k e s .

To max i mi ze f ue l economy, o f cour s e , t he r egener a t i ve b r ak i ng s ys t em

i s made t o do a s much o f t he b r ak i ng wor k a s pos s i b l e .


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Component Used in Toyota Pr ius for Regenerat ive Braking System:

B rak e Peda l :

I t i s u s ed t o app l y b r ak i ng f o r ce by t he d r i ve r .

Hydr au l i c Boos ter Un i t :

I t i s c o m p o s e d o f t h e m a s t e r c y l i n d e r a n d t h e r e g u l a t o r , r e s p o n d s i n

t wo s t eps . F i r s t i t s i gna l s e l ec t r on i ca l l y t o t he b r ake ECU t ha t b r ak i ng

f o r c e h a s be e n d e m a nd e d . N e x t , t h e ma s t e r c yl i n d e r e x er t s h yd r a u l ic

p res s u r e on t he peda l s t rok e s i mul a t o r , and t he r egu l a to r f eed s

hydr au l i c f l u i d t o t he hydr au l i c p r es s u r e con t r o l un i t .

B rak e ECU:

T h e b r a k e E C U s e n s e s t h e b r a k i n g d e m a n d a n d s e n d s a f r a c ti o n o f t h i s

demand t o t he THSECU f o r r egener a t i ve b r ak i ng .

I t a ls o c al cu la te s t he f or ce n ec e ss ar y t o f ul fi ll r em ai ni ng b ra ki ng

d e m a n d a n d i n s t r u c t t h e h y d r a u l i c p r e s s u r e c o n t r o l u n i t t o p a s s o n a

cor r es pond i ng amoun t o f hydr au l i c f l u i d

Ped a l S t r oke S im ula tor :

I t a b s o r b s a n a m o u n t o f h y d r a u l i c p r e s s u r e f r o m m a s t e r c y l i n d e r t h a t

co r r es ponds t o t he amoun t o f b r ak i ng f o r ce app l i ed by t he r egener a t i ve

b rak ing s ys te m.

A s h y d r a u l i c p r e s s u r e i s f e d b a c k t o t h e p e d a l , t h e p e d a l , t h e

p eda l s t rok e s imu la t o r f eeds ba ck t o the ma s t e r c yl in d e r .

THS (Toyo ta Hybr id Sys tem) ECU:

I t i n du c e s r e ge n e ra t iv e b r ak i ng , a n d r e tu r ns a s i gn a l t h at i n di c at e s

b rak ing f o r ce ou tpu t back to t he b rake ECU.

Hydr au l i c Pr es s ur e Co nt ro l Un i t :

I t p a s s e s o n a c o r r e s p o n d i n g a m o u n t o f h y d r a u l i c f l u i d t o a f o u r w a y

cy l i nde r .


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CHAPTER 6: RESULT

R eg en er at iv e b ra ki ng t ec hn ol og y i s o ne m or e p os it iv e s te p

f o r war d i n Toyo t a s ques t t o r ea l i ze t he u l t i ma t e eco ca r . By wor k i ng i n

c o n ce r t w i th p r ev i ou s ly d e ve l op e d e l ec t ri c m o to r t e ch n o lo g ie s , i t s

a p pl ic a ti on h e lp s T oy ot a s e le ct ri c v e hi cl es a n d h yb r id v e hi cl es

( i n c lu d i n g t h e r e c e n tl y r e l e as e d p r i u s ) t o a c h i e v e e x t e n d e d r a n g e s a n d

t o be f r iend l i e r t o t he env i r onment t han eve r be f o r e . A t t he s ame t i me ,

t h i s n e w t e c h n o l o g y r e m a i n s u n o b t r u s i v e l y i n t h e b a c k g r o u n d ; d r i v e r s

b ene f i t f r om r egen era t ive b r ak in g whi l e e n j o yi ng th e s ame f i r m b r ak i ng

f ee l f ound i n conven t i ona l l y equ i pped veh i c l e s .

7.1 Regenerative braking system using Nitinol Spring

Wheel

Rotating Device.

Shafts.

Gearbox Clutch Spring

Wheel A

Rotating Device B

Shafts C.D.

Gearbox E

Clutch G

Spring - H


21/27

A hydraulic regenerative braking system improves the fuel economyof Ford's F-350 Tonka 25-35% during stop-and-go driving. The

system provides power during initial acceleration when demand

peaks.

The HLA s ys t em cons i s t s o f a r eve r s i b l e hydr au l i c pump/ mot o r f r om

Eat on ' s F l u i d Power Gr oup ( Eden Pr a i r i e , MN) coup l ed t o t he d r i ve

s ha f t t h r ough a c l u t ch and t wo accumul a t o r s . As t he d r i ve r s t eps on t heb rak e , the pump / mot o r f o rc es hydr au l i c f lu i d ou t o f a lo w-p res s u r e

accumul a t o r and i n t o a h i gh- p r es s u r e accumul a t o r , i nc r eas i ng t he

p res s u r e o f n i t ro gen ga s s t o red th e re t o 5 ,0 00 p s i .

Dur i ng acce l e r a t i on , t he HLA s ys t em s wi t ches f r om t he pump mode t ot he mot o r mode , t he n i t r ogen gas f o r ces t he hydr au l i c f l u i d back i n t o

t he l ow- pr es s u r e accumul a t o r , and t he pump/ mot o r app l i e s t o r que t o t he

dr i ves ha f t t h r ough t he c l u t ch . I f qu i ck acce l e r a t i on i s r equ i r ed , t he F -350 ' s d i e s e l eng i ne wor ks wi t h t he HLA s ys t em


22/27

The hydr au l i c l aunch as s i s t s y s t em i n t he F- 350 Tonka f unc t i ons as as eco nda ry so ur ce o f ener gy d ur ing peak power d emand . I t cons i s t s o f a

l ow- pr es s ur e accumul a t or i n b l ue , and a h i gh- pr es s ur e accumul a t or i n

r ed . The s ys t em cap t ur es ener gy nor mal l y d i s s i pa t ed as hea t dur i ng

br eak i ng , s t or es i t , and us es i t l a t e r dur i ng per i ods o f peak power demand .

Ei gh t y pe r cen t o f t he i n i t i a l k i ne t i c ene r gy i s r e t u r ned t o t he veh i c l e .

"The s ys t em s t o r es appr ox i ma t e l y 380 kJ o f ene r gy , " s ays Br ad

Bohl mann , a mechan i ca l eng i nee r and bus i nes s deve l opmentcoor d i na t o r i n Advanced Techno l ogy a t Ea t on ' s F l u i d Power Gr oup .

"Wi t h t ha t much ene r gy , we can acce l e r a t e a 10 ,000- l b veh i c l e f r om a

dead s t op t o be t ween 25 and 30 mi l e s pe r hour w i t h no a s s i s t ance f r omt he veh i c l e ' s combus t i on eng i ne . "

"For d t h i nks t ha t bo t h e l ec t r i c and hydr au l i c r egener a t i ve s ys t ems have

a f u t u r e , " s ays J ohn Br ev i ck , a For d mechan i ca l eng i nee r wor k i ng on

t he HLA s ys t em. "Bu t f o r heavy veh i c l e s l i ke our 10 ,000- l b F - 350t r ucks , hydr au l i c s a r e be t t e r a t cap t u r i ng l os t ene r gy t han e l ec t r i c

s ys t ems . "

Ea t on ' s Boh l mann exp l a i ns t ha t t he r ea l advan t age o f hydr au l i c s i s i n

i t s power dens i t y . "Hydr au l i c s i s capab l e o f t r ans f e r r i ng ene r gy ve r yqu i ck l y , " s ays Boh l mann . "The r a t e o f ene r gy t r ans f e r i s i n a hybr i d

e l ec t r i c s ys t em of a s i mi l a r s i ze i s much l ower . "


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Bohl mann adds t ha t t he s pec i f i c voca t i on o r d r i v i ng cyc l e o f t he

veh i c l e de t e r mi nes whe t he r a hybr i d hydr au l i c o r hybr i d e l ec t r i c s ys t em

i s bes t s u i t ed f o r t he veh i c l e . "Th i nk o f hydr au l i c s a s a s p r i n t e r ,p ro v id i ng f a s t bu r s t s o f po wer , " he s ays . "An e lec t r i c h ybr id i s mo re

l i ke a mar a t hon r unner . "

"The cha l l enge now i s t o make us e o f t he r egener a t i ve b r ak i ng s ys t em

s eaml es s t o t he cus t omer , " s ays For d ' s Br ev i ck . "We s t i l l have r oom f o r i mpr ovement s and f ee l t he HLA s ys t em has a l o t o f po t en t i a l . "

As f o r t he f u t u r e , For d , Ea t on , and t he U .S . Env i r onment a l P r o t ec t i on

Agency ( EPA) a r e j o i n t l y conduc t i ng r e s ea r ch on hydr au l i c hybr i dveh i c l e s , i nc l ud i ng i n t e r na l combus t i on eng i nes t ha t wou l d p r oduce

hydr au l i c p r es s u r e t o d r i ve t he veh i c l e . Ea t on s i gned bo t h a t echno l ogy

l i cens e ag r eemen t and a cooper a t i ve r e s ea r ch and deve l opment

agr eemen t w i t h t he EPA f o r t he deve l opment o f f u t u r e gene r a t i on

s ys t ems .

Inert ia , Force and Mass

Ever y t h i ng has i ne r t i a ; i f i t has a mas s , i t has i ne r t i a . A hybr i d

r ec l a i ms ene r gy t h r ough t he f undament a l s o f phys i c s . Do you r emember any h i gh s choo l o r co l l ege phys i c s ?

You app l y a f o r ce t o move an ob j ec t . The equa t i on f o r t h i s i s :

F=ma

F be i ng t he f o r ce , m be i ng t he mas s and

a be i ng t he acce l e r a t i on

The f a s t e r you wan t an ob j ec t t o acce l e r a t e , t he mor e f o r ce you have t o

app l y .

Le t s j u s t l ook a t t he e l ec t r i c mot o r f o r now. Ener gy f r om t he ba t t e r y( Wat t s ) i s app l i ed t o t he co i l w i nd i ngs i n t he mot o r . Thes e wi nd i ngs

t hen p r oduce a magne t i c f o r ce on t he r o t o r o f t he mot o r , wh i ch

p ro duces t o rq ue on the o u tpu t s ha f t . Th i s to r que i s th en app l i ed t o t he

whee l s o f t he ca r v i a a coup l i ng o f gea r s and s ha f t s . When t he whee lt u r ns , i t app l i e s a f o r ce t o t he g r ound , wh i ch due t o f r i c t i on be t ween

t he whee l and t he g r ound caus es t he veh i c l e t o move a l ong t he s u r f ace .Th i s i s l i ke i f you wer e i n a boa t a t a dock , and you g r abbed t he dock and pus hed wi t h your a r m. The f o r ce you a r e gen e r a t i ng i s mov i ng t he

b oa t r e l a t iv e t o th e loc a t io n o f the d ock . Th e mor e f o r ce you ap p l y , t he

f as t you ge t t he boa t t o move .

Fric t ion in Hybrids

Ther e i s f r i c t i on eve r ywher e i n t he hybr i d s ys t em. Ther e i s e l ec t r i ca l


24/27

f r i c t i on be t ween t he a t oms and e l ec t r ons movi ng i n t he w i r es be t ween

t he ba t t e r y and t he mot o r and t h r ough t he mot o r i t s e l f . Ther e i s

magne t i c f r i c t i on i n t he me t a l l ami na t i ons t ha t make up t he magne t i cc i r cu i t o f t he mot o r , a s we l l a s i n t he magne t s aga i n on t he a t omi c

l eve l . Then , t he r e i s mechan i ca l f r i c t i on be t ween eve r y movi ng pa r t ,

s uch as t he bea r i ngs , s ea l s , gea r s , cha i ns and s o on . The by- p r oduc t o f f r i c t i on i s hea t . Take your hands r ub t hem t oge t he r and your pa l ms ge t

war m. The f a s t e r you do i t , t he f a s t e r t hey hea t up . A l s o , t he ha r de r

t hey a r e p r es s ed t oge t he r , t he f a s t e r t hey wi l l hea t . F r i c t i on i s ene r gyl os t t o hea t . When a l l o f t hes e l os s es a r e added up , t ha t i s wha t

de t e r mi nes t he e f f i c i ency o f t he veh i c l e .

Fric t ional Losses in Convent ional Cars

A s t andar d ca r gene r a t e s t o r que t o move t he whee l s t o d r i ve t he veh i c l edown t he r oad . Dur i ng t h i s t i me , i t i s gene r a t i ng f r i c t i on and l os s es .

When you app l y s t andar d b r akes , i t i s j u s t ano t he r f r i c t i on dev i ce t ha t

has s pec i a l l y des i gned ma t e r i a l t o hand l e t he hea t f r om f r i c t i on , wh i chi s app l i ed t o t he d r ums and r o t o r s t ha t s t op t he whee l f r om t u r n i ng . The

f r i c t i on be t ween t he whee l and t he g r ound s t ops t he veh i c l e . Th i s

s t andar d veh i c l e has f r i c t i ona l l o s s es t o move t he veh i c l eand us es t he

f undament a l beh i nd f r i c t i ona l l o s s es t o s t op t he veh i c l e . So i t s a l o s e -l os e s i t ua t i on .

Transferr ing Torque Back to the Motor

Thi s i ne r t i a i s t he f undament a l p r ope r t y o f phys i c s t ha t i s u s ed t o

r ec l a i m ene r gy f r om t he veh i c l e . I ns t ead o f us i ng 100% of t hef ounda t i on b r akes o f t he veh i c l e , wh i ch a r e t he f r i c t i on b r akes , we now

l e t t he l i nkages back t o t he mot o r s uch as t he d r i ve s ha f t s , cha i ns , andgea r s t r ans f e r t he t o r que f r om t he whee l s back i n t o t he mot o r s ha f t .One o f t he un i que t h i ngs abou t mos t e l ec t r i c mot o r s i s t ha t e l ec t r i ca l

ene r gy can be t r ans f e r r ed i n t o mechan i ca l ene r gy and a l s o mechan i ca l

ene r gy can be t r ans f e r r ed back i n t o e l ec t r i ca l ene r gy . I n bo t h ca s es ,t h i s can be done ve r y e f f i c i en t l y .

Thus , t h r ough t he t echno l ogy o f t he mot o r and mot o r con t r o l l e r , t he

f o r ce a t t he whee l s becomes t o r que on t he e l ec t r i c mot o r s ha f t . The

magne t s on t he s ha f t o f t he mot o r ( ca l l ed t he r o t o r t he movi ng pa r t o f t he mot o r ) move pas t t he e l ec t r i c co i l s on t he s t a t o r ( t he s t a t i ona r y pa r t

o f t he mot o r ) pas s i ng t he magne t i c f i e l ds o f t he magne t s t h r ough t he

co i l s p r oduc i ng e l ec t r i c i t y . Th i s e l ec t r i c i t y becomes e l ec t r i ca l ene r gy ,whi ch i s pumped back t o t he ba t t e r y . Th i s , i n t u r n , cha r ges t he hybr i d

b a t t e r y p ack . Th i s i s whe re t he comme nt r egene ra t ion o r r ec la i ming

ener gy comes f r om.

Tha t i s t he bas i c s o f how r egener a t i on wor ks . How much ene r gy youcan r ec l a i m depends on a l o t o f f ac t o r s . Ther e a r e d i f f e r en t


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r egener a t i on t heor i e s and des i gns , wh i ch f a l l i n t o t wo g r oups : one

b e in g ca l l ed pa r a l l e l r eg en and th e o th e r ca l l e d se r i e s r egen , wh i ch a r e

d i f f e r en t f r om t he pa r a l l e l and s e r i e s hybr i ds . Thes e r egen g r oupss t r i c t l y a r e des i gn t opo l og i es f o r b r ak i ng s ys t ems . I t a l s o ma t t e r s how

many whee l s you a r e us i ng t o r ec l a i m ene r gy . Mos t veh i c l e s t o da t e a r e

f r on t whee l d r i ve s o you can on l y r ec l a i m ene r gy f r om t he f r on twhee l s . The back whee l s s t i l l was t e ene r gy t o s t andar d f r i c t i on b r akes

un l es s t hey a r e s omehow connec t ed back t o t he e l ec t r i c mot o r . The

o t he r f ac t o r i s ba t t e r y s t a t e o f cha r ge and how ha r d can you d r i ve t ha tene r gy back i n t o t he ba t t e r y .


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CHA PT ER 7: CONCLUSION

Theor e t i ca l i nves t i ga t i ons o f a r egener a t i ve b r ak i ng s ys t em s how abou t

25% s av i ng i n f ue l cons umpt i on .

T h e l ow e r o p er at in g a nd e nv ir on me nt c o st s o f a v eh ic le w it h

r eg e ne ra ti ve b ra ki ng s ys te m s ho u ld m ak e i t m or e a t t ra ct iv e t ha n a

c on ve nt io na l o ne . T he t ra di ti on al c os t o f t he s ys te m c ou ld b e

r ecover ed i n t he f ew yea r s on l y .

The exhaus t emi s s i on o f veh i c l e us i ng t he r egener a t i ve b r ak i ng concep t

w o u l d b e m u c h l e s s t h a n e q u i v al e n t c o n v e n t i on a l v e h i c l e s a s l e s s f u e l

a r e us ed f o r cons umpt i on .

Thes e s ys t ems a r e pa r t i cu l a r l y s u i t ab l e i n deve l op i ng coun t r i e s s uch as

I n d i a w h e r e b u s e s a r e t h e p r e f e rr e d m e a n s o f t r a n s p o r ta t i o n w i t h i n t h e

c i t i e s .


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BIBLIOGRAPHY

1) Genera l Motors Webs i te ( www.gm.com ) .

2 ) w w w. s ae . or g

3 ) w ww .g oo gl e. co m
http://www.gm.com/http://www.gm.com/

23291564 regenerative braking system (1)

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