Fall 2008-Project Final3 Dec09-2008

8/10/2019 Fall 2008-Project Final3 Dec09-2008

1/29

Battery Management System for Hybrid Electric Vehicles (HEV)

University of Windsor Department of Electrical and Computer Engineering

06-88-514 !dvanced "o#er $ystems % &all '008

ATM OMAR FAR ! ESt"dent #$ % &'' &* &

M$+ ,AHA-.#R TO#MOOR St"dent #$ % &'*'*/'&0

M$+ SHAH#$ 1 HA! E

St"dent #$ % &'&23& 4

$ate of S"bmission5 &&6&262'' +


2/29

Battery Management System for Hybrid Electric Vehicles (HEV)

1( Abstract

)*e *y+rid electric ve*icle , E./ com+ines t*e conventional internal com+ustion C/ engine #it*a +attery po#ered electric motor( )*e cost of energy consumed as #ell as causes of environment and air

pollution can +e reduced +y optimi ing t*e ratings of t*e +attery and engine( )*e E. saves fuel +y using

electric motor t*at *elps C engine at t*e time of acceleration and also use t*e 2inetic energy of +ra2ing( a *y+rid electrical ve*icle3 t*e +attery acting as an energy +uffer3 t*e engine can +e operated at *ig*er efficiencyspeed and load points +y carefully integrating engine operation #it* operation of t*e electric motor andtransmission( attery management system includes t*e display3 control3 monitoring of different +attery

parameters( $afety and efficiency are also ot*er important factors to +e considered( !+ove all t*e performance of t*e +attery is a ma or issue to +e dealt #it*( )*is is a prime concern( $o3 our o+ ective is tofind t*e optimum +attery tec*nology availa+le for use in E.( We *ave gone t*roug* various +oo2s3 EEE

ournals3 EEE e plorer #e+sites and resources to find t*e attery management system of E.( We *avefocussed on t*e centrali ed and distri+uted attery management system( We *ave e plored t*e +atteryc*aracteristics and ot*er parameters of t*e present and future *y+rid electric ve*icle(

25 #nde7 Terms5 attery3 attery 7anagement $ystem3 y+rid Electric .e*icle3 C*arging3 $ C


3/29

*+ -omenclat"re5

CU attery Control Unit

7$ attery 7anagement $ystem

7U attery 7onitoring Unit

E. Electric .e*icle

E. y+rid Electrical .e*icleCE nternal Com+ustion Engine

9i-ion +atteries 9it*ium-ion +atteries

:i-7 :ic2el-7etal- y+rid attery

$ C state of c*arge

$ & $tate of &unction

$ $tate of ealt*

."C .oltage per Cell

.;9! . alue ;egulated 9ead !cid


4/29

3+ #ntrod"ction

Environment and pollution are one of t*e ma or concerns of modern civili ation #*ic* is associated#it* many *uman *ealt* pro+lems( Cars and truc2s #e drive3 mostly po#ered +y petroleum-+ased fossilfuels li2e gasoline and diesel3 are ma or source of air pollution( )*e automo+ile manufacturers and usersare +ecoming increasingly a#are of t*ese t#o elements( )*e ve*icle manufacturers are also t*in2ing for along time for t*e eco friendly ve*icle( 7oreover3 t*e cost and t*e availa+ility of t*e fossil fuel areincreasing day +y day( $o3 t*ere is a need for t*e mitigating t*ese issues( )*e automo+ile Companies are

trying to overcome t*is pro+lem +y ma2ing electric3 *y+rid3 or *ydrogen fuel ve*icles(

n a *y+rid electrical ve*icle3 t*e +attery acting as an energy +uffer3 t*e engine can +e operated at *ig*er efficiency speed and load points +y carefully integrating engine operation #it* operation of t*e electricmotor and transmission( f desired3 larger-capacity electric motors and +attery pac2s can +e used to supplyenergy at lo# speeds and loads3 allo#ing t*e engine to +e s*ut off under inefficient conditions( )*eem+edded computers can trac2 t*e energy content of t*e +attery and optimi e t*e load division +et#een

+attery and engine for a specific route( )*e engine #ill deliver more po#er avoiding deep disc*arges of t*e +attery(

! *y+rid electric ve*icle is *eavier and its initial cost is *ig* +ecause it re


5/29

cost #ill +e *ig*( t*er impacts li2e danger3 #aste3 space3 material are not considered at all in t*isdocument so far( We *ave e plored some facts t*at can *elp to find solutions(

)*is pro ect discusses on t*e 7$ of E.( We #ere *aving *ard times on finding t*e supportingdocuments( )*ere is a s*ortcoming of t*e necessary +oo2s3 ournal and supporting documents( We *avedone an e tensive #e+ searc* and it includes EEE e plore and many tec*nical ournals and maga ines(We got some +oo2s from t*e li+rary also( )*is is very recent and evolving issue( ;esearc*ers arefocussing on t*is to *ave a +etter solution at reasona+le price(

0+ Electric Vehicle5

Electric ve*icle are 2no#n as ero emission ve*icles( t uses +atteries as electrical energy storagedevice to dra#ing current from rec*argea+le storage +atteries and motors to propel t*e automo+ile()*ousands of electric ve*icles +uilt +y variety of manufacturers included private cars3 delivery vans and

+uses( )*e electric ve*icles *ave some advantages over t*e C engine"ollution free

ig* efficiency9ess :oise9ig*ter3 smaller3 relia+le

Easy to maintenance

Fig. 1: Schematics diagram of electric power train

)*e electric ve*icles *ave some pro+lems in storing energy( )*e energy storage density is very lesst*an C engine( Components used in electric ve*icles are usually designed and +uilt for ot*er purposes(


6/29

4+ 8hat are hybrid electric 9ehicles:

)*e *y+rid electric ve*icle , E./ com+ines t*e conventional internal com+ustion C/ engine #it* a +attery po#ered electric motor( )*e E. saves fuel +y using electric motor t*at *elps C engine at t*etime of acceleration and also use t*e 2inetic energy of +ra2ing( )*e C motor turns off at t*e time of stopand #*en t*e ve*icle is running slo#(

)*e C engine and t*e motor +ot* are engaged #*en full po#er is reit re


7/29

Fig. 3: Series HEV architecture

4+2 ;arallel hybrid system5 n parallel *y+rid system3 +ot* t*e engine and t*e electric motor areconnected directly to t*e drive train( $o t*e tor


8/29

Fig. %: !arallel HEV architecture "engine#transmission#motor configuration$

6(@ Degree of y+ridi ation

t is a 2ey factor to 2no# t*at #*ic* part of t*e po#er train *as +een *y+ridi ed +yt*e additional of electric po#er( !n E. #it* a lo# percentage of pea2 po#er o+tainedfrom electric motor is 2no#n as mild *y+rid or lig*t *y+rid3 #*ile an E. #it* *ig*

percentage of pea2 po#er o+tained from electric motor is 2no#n as full *y+rid or *eavy*y+rid

n &ig( A t*e percentage of pea2 po#er is o+tained from electric motor is plotted(

AAAAAAAAAAAAAAAAAAAAAAAAA"age-116-11B

/+ Rene


9/29

+ F"el cell =o


10/29

&ig( 6 ro#t* of population and ve*icles(

+ The f"nction of a BMS can be s"mmari>ed as follo


11/29

)*e +attery voltage must matc* t*e motor voltage and t*e availa+ility of products *as to +e ta2en intoaccount( )*e energy contentFpo#er capa+ility is t*e most influential varia+le( W*en energy content andt*e po#er capa+ility of t*e +atteries are *ig*3 t*e +attery si e3 cost and mass #ill increase( )*e type of temperature control can +e natural cooling #it* lo#est comple ity( )*e #eig*t of +atteries s*ould +eminimum( )*e decision a+out coolingF*eating is made later after testing t*e +attery and investigations of in-ve*icle +e*aviour(

9ongevity of t*e cell is a ma or issue of t*e +atteries of E.( E. in general uses t*e only 10= of t*e rated +attery capacity( t allo#s t*ousands of c*arge disc*arge cycles( )*e limitation of t*e :i7 ist*at its energy conversion efficiency is moderate(

)*e c*arge efficiency is #or2s +est for t*e 50-B0= state of c*arge( )*e test s*o#s t*at a+ove t*eB0= state of c*arge +atteries can not a+sor+ c*arge #ell and t*e c*arging energy is lost as *eat( f a

+attery is operate on partial c*arge t*an it re


12/29

&'+2 The im=ortant characteristics of the HEV battery =ac? are5

1/ Capa+le of calculating t*e state of c*arge module voltage and temp('/ Capa+le of determining and communicating to t*e pac2 operating limit to t*e ve*icle controller @/ Capa+le of t*ermally manage t*e +attery pac2 in *eating and cooling modes(4/ Capa+le of correcting coulom+ im+alances #it*out t*e fre


13/29

-ic?el Metal Hydride (-i MH)5

:i-7 +atteries *ave *ig*er po#er and energy densities and longer life cycle t*an lead-acid +atteries( t is #ell suited for *ig*-po#er *y+rid design and t*at?s #*y )oyota "rius3 onda nside3 ondaCivic y+rid c*oice t*is +attery(

:i-7 +attery #as introduced as a su+stitute of t*e nic2el cadmium +attery( !t present t*e nic2elmetal *ydride +attery is one of t*e #idely used +atteries of t*e E.( :ic2el ydro ide is used as cat*odeand t*e anode material is *ydrogen and it is reversi+ly stored as metal *ydride( !


14/29

'/ 9it*ium metal polymer(@/ 9it*ium ion polymer 4/ 9it*ium ion

)*e lit*ium +ased +atteries *ave t*e follo#ing disadvantages Calendar life)*e +attery is used for a very s*ort period of time and it remains stand +y for a long time( )*e *ig* lit*iumvoltage and t*e lit*ium reactivity against t*e electrolyte and t*e e treme environmental condition t*e

+attery are e posed to in t*e ve*icle *ave a great effect on t*e calendar life(

)emperature range e tension)*e cell conductivity decreases at lo# temperature3 mainly due to electrolyte( t negatively

influences t*e disc*arge po#er performance and it prevents t*e adoption of an aggressive regenerating +rea2ing strategy( )*e lit*ium +attery operation at *ig* temperature is an important issue(

Cinc Bromide5 )*is +attery *as t*e ig* energy density and long cycle life( ut t*is is comple and to ic(! inc-+romine +attery passes t*roug* an ion-e c*ange mem+rane t#o oppositely c*arged li


15/29

Type Density[ h!"g#Density[ !"g# $ife Te%p. [C# Te%p. [C#

Discharge&ate

[' per %onth#

Cost[(!" h#

Cost)(!" h# *se+,-n otes

Lead-Acid 25 to35 75 to130

200to

400

-18 to+70 ambient 2 to 3 production

100 to125 75

Trojan,Haw er,!"ide,

#nter$tate

%A&TAbu$,

'o(ectria!10

)$ea(ed*

Ad anced Lead Acid 35 to42240 to

412

500to

800 production

e(p i,Hori.on,

!(ectro$ource

Audi

uo, /! 1

) L&A*,'o(ectria

orce

otentia(556

4506 ,

and 2000c c(e (i9

:ic e(- eta( H dride 50 to80150 to

250

;00to

1500 protot pe 525 to540

115 to300

ana$onic,< onic,'A T

To ota&A 4-

! ,To ota

riu$,% r $(er

!picmini an,Honda

! ,% e'-10

otentia(1206

and 2200

c c(e (i9

:ic e(-%admium 35 to5750 to200

1000to

2000

-40 to+;0

-;0 to+;0

10 to20 mature

300 to;00 110 'A T

=i in23

otentia(2200

c c(e (i9

Lit ium-#on 100 to150 300400to

1200 (aborator ', 'A T :i$$an A(tra !

otentia(1000

6

?inc-@romide 5; to70 100 500 300

Lit ium o( mer 100to 155100 to315

400to

;00

;0 to100 (aborator 100

:a:i%( 0 100 270 to

350 )300optima(*

400 protot pe A!/ An (o

?inc-Air 110 to200 100 240

to450

protot pe 300 100 LiBuid ue(Ltd

anadium &edo" 50 110 400 300

&&+The Ragone =lot5)*e ;agone plot is an important grap*ical tool for understanding various +attery c*aracteristics(Depending on t*e load t*e stored electrical energy s*o#s different c*aracteristics( )*ese c*aracteristics arenon linear( W*en t*e cells are c*arged and disc*arged at *ig* rate t*e losses are *ig*er( !t t*is stage t*ecells s*o# more decreased capacity t*an t*e nominal ones( ;agone introduced a plot summarising t*eresults of many measurements performed #it* different po#er rate and co related t*e result #it* energystorage #eig*t(


16/29

Fig.+: ,agone !lot of the energy storage de*ices.

)*e ragone plot s*o#s t*e specific energy and specific po#er relations*ip and #it* t*is means anovervie# of t*e cell +e*aviour for t*e different disc*arge rate( $o t*e ragone plot s*o#s an easy #ay of t*e

po#er limit of an energy storage system( t also *elps to identify t*e optimal operative range for eac*energy storage( &igure s*o#s t*e ragone plot for various E. ve*icles( n t*e ragone plot eac* c*emistryis #ell defined in a #ell defined area( t also *ig* lig*ts t*e specific operative range(

&2+Factors affecting Battery =erformance

&2+& Tem=erat"re5

attery performance is *ig*ly dependent on temperature( Eac* type of +attery #or2s +est #it*in alimited range of temperatures( Concerns related to +attery temperature include

"oor energy and po#er e traction performance for temperatures outside of operating temperaturerange

)*ermal runa#ay - during *ig* po#er e traction t*e temperature of t*e +attery increases #*ic*ma2es furt*er po#er e traction more difficult #*ic* causes su+se


17/29

)*e impact t*at temperature e erts on +attery capacity can +e e plained #it* a simple model of t*e +attery electroc*emistry( !s t*e temperature increase to#ards t*e pea2-performance-operating temperaturet*e electrolyte viscosity decreases3 t*us allo#ing for increased diffusion of ions and *ence increased

+attery performance( !s t*e temperature increases past t*is pea2 point3 t*e +attery electrodes +egin tocorrode - t*us leading to a reduced IactiveI electrode area and t*us to fe#er electrode reactions andreduced +attery capacity(

)*e +attery t*ermal management of a *y+rid pac2 is more difficult +ecause of t*e lo#er +attery mass(E. also re


18/29

ellTem=erat"re

Fig. -: &ell &urrent

)*e *ard#are is used for t*e cell protections are as follo#s

Thermal F"se5 ig* temperature covers t*e cell failure( $o most protections cut includes a t*ermal fuse#*ic* isolates t*e cell in case of *ig* temperature(Thermistor5 )ermistors are used for cell protection( C*arger can also use t*e value of t*ermistor in orderto determine cell temperature(Resettable f"se5 ;esetta+le fuse provides t*e +attery over current protection

&2+3 Voltage ;rotection5)*e cell may +e damaged +y +ot* over voltage and under voltage( ver voltage occurs during t*e time ofc*arging and under voltage occur during t*e time of disc*arging( $o3 t*ere s*ould +e a voltage limit for

+ot* c*arging and disc*arging( n fact +atteries are vulnera+le to overc*arging(

)*e follo#ing diagram +riefly descri+es t*e safe operation one

Voltage ;rotection5

ellTem=erat"re

Fig.1 : &ell Voltage

1'(1 Battery harging5&*+& harging system5 )*is is necessary to minimi e t*e capacity deviations among t*e modules of t*e

+attery pac2( )*e c*arging efficiency is increased +y t*e using c*arging algorit*mC*arging of t*e +attery do t*ree important functions

a/ C*arging t gets t*e +attery c*arged +/ $ta+ilising t optimi es t*e c*arging ratec/ )erminating t determines #*en to stop c*arging(


19/29

&*+2 State of harge )*e $tate of C*arge of a +attery is its availa+le capacity e pressed as a

percentage of its rated capacity( )*e $ C of a +attery is its availa+le capacity e pressed as a percentage of

its rated capacity( Determining t*e $ C of t*e +attery is a ma or function of t*e 7$( )*e $ C is needed

not ust for providing t*e &uel auge indication( )*e 7$ monitors and calculates t*e $ C of eac*

individual cell in t*e +attery to c*ec2 for uniform c*arge in all of t*e cells in order to verify t*at individual

cells do not +ecome overstressed(

)*e $ C indication is also used to determine t*e end of t*e c*arging and disc*arging cycles( ver-c*arging and over-disc*arging are t#o of t*e prime causes of +attery failure and t*e 7$ must maintaint*e cells #it*in t*e desired D D operating limits( y+rid ve*icle +atteries re


20/29

&*+* Safe harging5

f a +attery is c*arged for a long time t*ere #ill +e a rise in temperature( nternal fault or *ig*temperature may also cause t*e *ig* temperature of +attery( $o a limit a limit safe c*arging s*ould +eensured( )*e self-disc*arging rate $,) a3)/ is a function of t*e temperature ) and t*e usage time ) a of t*e

+attery pac2 as s*o#n &ig( +elo#

Fig.12: Self discharging rate *s. usage time of 0i# H battery

!t t*e same time3 t*e c*arging efficiency is selected according to t*e curve s*o#n in &ig(5(

&ig(1@ C*arging efficiency vs( temperature of :i-7 +attery


21/29

&*+3 harging times5

&ast c*arging causes an increase in t*e cell temperature( ecause fast c*arging needs *ig*er currentflo# and if stimulator fast c*emical conversion process( $o3 standard time s*ould maintain for +atteryc*arging( Depending in t*e re


22/29

)*e c*arging sc*eme is usually provided +y t*e +attery manufacturer3 +ut some general comments s*all +emade( atteries can +e c*arged #it* a DC or pulse current( )*e c*arging process consists of differentc*arging p*ases

1/ nitial or +ul2 c*arging p*ase'/ !+sorption c*arging p*ase@/ &loat c*arging p*ase4/ E


23/29

&/+ The Battery management system (BMS)5

!ll +attery management system *as t*e follo#ing t*ree o+ ectives

1/ )o protect t*e cell or +attery from damage('/ )o prolong t*e life of t*e +attery(@/ )o maintain t*e +attery in suc* a condition t*at it can fulfill t*e function re


24/29

Fig.1 : 'attery anagement System a sample diagram

)*e system needs an ac


25/29

n t*e automotive engineering 7$ is a fast acting energy management system( 7$ *as t*einterface #it* ot*er on +oard system li2e engine management3 climate control communications and safetysystem( )*e 7$ #or2s in t*e real time fast c*anging c*arging and disc*arging condition(

n practice t*e more function t*an managing t*e +attery( t determines t*e ve*icle operating mode li2e#*ile it is accelerating3 +ra2ing3 idling or stopping( !ccording to t*e status it implements t*e reed5 n t*is system a single controller is used( )*e controller is connected to t*e +attery

cells t*roug* of #ires( +/ $istrib"ted5 n t*is system a 7$ +oard is installed at eac* cell( ! single communication ca+le is

used +et#een t*e +attery and a controller(c/ Mod"lar5 n t*is system controllers are fe#( Eac* of t*e controllers *andles a certain num+er of

cells and t*ey communicate #it* eac* ot*er(

&/+2 A ty=ical battery management system5

Fig.1): &on*entional battery management system

)*e a+ove figure s*o#s a typical +attery management system( )*e 7$ consists of an Electronic controlunit,ECU/ and an e


26/29

connected to t*e C!: +us( f it detects any t*eft it #ill disa+le t*e +attery( )*ere is also a provision for t*e;$'@' serial +us #*ic* can +e used as monitoring and programming( attery monitoring unit ismicroprocessor +ased control unit #*ic* incorporates ot*er su+ modules(

&ig(18 loc2 diagram of centrali ed attery 7anagement $ystem(

)*is is a centrali>ed battery management system ( t *as t*e s*ort comings of no redundancy( )*etotal management system is dependent on a single unit( )o ensure redundant system is costly and in case of

failure all t*e system #ill fail( $o t*ere is a need for a decentrali ed system( )*e management and faultrecovery +ecomes an easier approac* in a decentrali ed system(

& + Battery management system a decentrali>ed a==roach5

)*e decentrali ed +attery management system provides t*e fle i+ility for t*e operation andmaintenance( )*is is li2e a fail safe approac*( n t*e follo#ing system #e s*all try to e plain t*is(


27/29

Fig.1-: 'loc diagram of decentrali4ed battery management system.

)*e system consists of a C7U( t also *as a num+er of D!7( )*e no( of data ac


28/29

) *e data ac


29/29

2'+ oncl"sion5

)*e +attery management system plays in important role for E.( !s +attery is t*e main source of energyand to +e managed so in t*is study #e *ave discussed various +attery and t*eir c*aracteristics( )*e +atterymanagement system is composed of various modules and it performs t*e re

Fall 2008-Project Final3 Dec09-2008

Documents

Transcript of Fall 2008-Project Final3 Dec09-2008