Energy Management Strategy Considering Cabin Heating for Plug-in Hybrid Electric Vehicle

Transcription

1 EVS28 KINTEX, Kora, May 3-6, 215 Enrgy Managmnt Stratgy Considring Cabin Hating for Plug-in Hybrid Elctric Vhicl Hjin Shin 1, Sunyoung Park 1, Jamyoung Pi 1, Jingyu Choi 1, Sulgi L 1, Hyunsoo Kim 1, Inbom Yang 2 1 School of Mchanical Enginring, Sungkyunkwan Univrsity, 266, Sobu-ro, Jangan-gu, Suwon-si, Gyonggi, Kora, bwbw6387@hanmail.nt 2 Smart Vhicl Tchnology R&D Division Kora Automotiv Tchnology Institut, 33 Pungs-ro, Pungs-myon, Dongnam-gu, Chonan-si, Chunggnam, Kora, ibyang@katch.r.kr Abstract In this study, an intgratd nrgy managmnt stratgy(iems) was proposd for a PHEV(Plug-in hybrid lctric vhicl). Th IEMS controls th ngin on-off considring not only powrtrain systm(battry SOC, vhicl spd, acclrator pdal, brak pdal) but also thrmal systm condition such as cabin tmpratur. Analysis of th intgratd powrtrain and thrmal systm was conductd to nhanc vhicl prformancs such as all lctric driving rang and ful conomy. To invstigat th nrgy flow, th prformanc simulator was dvlopd basd on th intgratd powrtrain and thrmal systm modl. Th powrtrain modl is composd of th ngin, motor-gnrators, powr-split transmission, battry and vhicl dynamics, whras th thrmal systm modl is composd of th thrmal ngin, radiator, hatr and cabin. From th simulator, th coolant tmpratur, cabin tmpratur, ngin torqu and ngin spd wr invstigatd. Th dvlopd simulator was validatd by vhicl tst rsults. It was found that th proposd IEMS satisfis th dmandd cabin tmpratur whil providing improvd ful comsumption compard with th xisting nrgy managmnt systm. Kywords: intgratd nrgy managmnt stratgy(iems), thrmal systm, plug-in hybrid lctric vhicl(phev) 1 Introduction According to th rnwd rgulation of Environmntal Protction Agncy(EPA) in masurmnt of ful fficincy, not only th convntional vhicl but also th hybrid lctric vhicl and th plug-in hybrid lctric vhicl rquir to considr th surrounding tmpratur of summr and th wintr for xisting driving cycls, th urban dynamomtr driving schdul (UDDS) and highway ful conomy tst (HWFET). In rspons to this rquirmnt, importanc of th thrmal managmnt systm has bn incrasd[1]. Th thrmal managmnt systm of th vhicl can b dividd into th cooling systm for powrtrain and th air condition/hating systm for th drivr s convninc. Sinc th thrmal managmnt systm consists of many lctric dvics, it rquirs lctric nrgy of th battry. For xampl, th ful fficincy tst rsults of th Chvrolt Volt for UDDS and HWFET showd that th usag of battry for hating aggravatd th ful fficincy furthr than th usag of ngin[2]. EVS28 Intrnational Elctric Vhicl Symposium and Exhibition 1

2 In this study, an intgratd powrtrain-thrmal managmnt simulator of powr-split typ PHEV was dvlopd and intgratd nrgy managmnt stratgy(iems) was proposd to improv th ful conomy. 2 Dvlopmnt of th PHEV Powrtrain Simulator 2.1 PHEV powrtrain simulator Th thrmal managmnt systm of th targt PHEV is dtrmind by th powrtrain opration condition such as th battry SOC, ngin torqu, ngin spd. Thrfor, th powrtrain simulator should b dvlopd in advanc for dvlopmnt of th intgratd powrtrainthrmal managmnt simulator Structur and th spcification of th PHEV Th powrtrain systm of th targt PHEV consists of 1 ngin, 2 motors(mg1/mg2), 1 battry and 1 plantary gar. Th structur of th PHEV is shown in Figur 1 and th vhicl spcification is shown in Tabl 1. Engin Battry C1 MG1 MG2 C2 Ring Carrir Sun Diffrntial gar Figur 1: Structur of th targt PHEV B1 Tabl 1: Spcification of th targt PHEV[3] Itm Spcification Engin Displacmnt 1398cc Max output 62kW/48rpm MG2 Max powr 111kW Max torqu 37Nm MG1 Max powr 55kW Final rduction gar ratio 2.16 Vhicl Plantary gar ratio 83/37 Tir radius.3382m Mass 1717kg Engin and MG1/MG2 modl Engin torqu is dtrmind from th ngin charactristic map by th acclration pdal opning for th ngin spd. Powr loss of th MG1/MG2 is dtrmind by th motor fficincy map(figur 2). Figur 2: Motor fficincy map[4] Vhicl modl Vhicl was modlld considring th traction forc, brak forc and th roadload. Rolling rsistanc and air drag forc wr obtaind basd on th coastdown tst rsults and th gradint rsistanc was calculatd using vhicl dynamics. Th vhicl dynamics is as follows: MV Fdriv Fbrak Froadload (1) whr M is th vhicl mass, V is th vhicl vlocity, Fdriv is th traction forc, Fbrak is th brak forc, Froadload is th roadload. 3 Dvlopmnt of th Intgratd Simulator 3.1 Thrmal managmnt systm simulator Th thrmal managmnt systm was modlld and prformanc simulator was dvlopd Structur of th thrmal managmnt systm As can b sn in Figur 3, th thrmal managmnt systm consists of th radiator, thrmostat, ngin, PTC hatr, hatr cor and th blowr. Undr th hating condition, hatr cor is warmd up by th coolant which is hatd by th ngin wast hat or th PTC hatr. Th air is also warmd up whil passing through th hatr cor and flows into th cabin by th blowr. Th cabin tmpratur is dtrmind by th hat of PTC hatr, drivr, loss, tc. EVS28 Intrnational Elctric Vhicl Symposium and Exhibition 2

3 Q loss Q drivr Q hatr Blowr Radiator Thrmostat Engin PTC hatr Hatr cor Air cooling Coolant flow Figur 3: Thrmal hat transfr in th targt PHEV Engin thrmal modl Figur 4 shows th distribution of ngin ful powr. Th amount of hat transfrrd to th coolant from th ngin can b obtaind as follows: Q Q T Q (2) coolant ful _ loss whr Q coolant is th hat transfrrd to th coolant, Q ful is th total hat of ful, T is th ngin torqu, is th ngin spd and th Q _ is th hat loss. loss Engin Input Powr Engin Output Powr Figur 5: Hat transfr from th PTC lmnt to coolant 3.2 Intgratd powrtrain-thrmal managmnt systm simulator Figur 6 shows th intgratd powrtrain-thrmal managmnt systm simulator dvlopd in this study. Figur 4: Distribution of th ngin ful powr PTC hatr and th hatr cor modl In EV mod whn th ngin is not opratd, th PTC hatr is usd to hat th coolant. Th PTC lmnt is hatd from th battry powr and warms up th coolant. Th amount of hat transfrrd to th coolant from th PTC lmnt is calculatd as follows: QPTC coolant Ccoolantm coolant( TPTC Tin) (3) whr Q is th hat transfrrd to th PTC coolant coolant from th PTC hatr, Ccoolantis th spcific hat of th coolant, mcoolant is th coolant mass, T PTC is th tmpratur of th PTC lmnt, Tin is th tmpratur of th coolant which coms into th PTC hatr. Figur 6: Intgratd powrtrain-thrmal managmnt simulator Vhicl dynamo tst condition Th intgratd powrtrain-thrmal managmnt systm simulation rsults wr compard with th vhicl dynamo tst rsults. Th tst condition for CD mod is shown in Tabl 2. Tabl 2: Vhicl dynamo tst condition(cd mod) Itm Spcification Driving mod FTP 75 Air flow Max Stting tmpratur(tst) Max(32 ) Stting tmpratur(simulation) 34 Initial SOC 8% Initial cabin tmpratur 7.4 EVS28 Intrnational Elctric Vhicl Symposium and Exhibition 3

4 3.2.2 Comparison btwn th simulation and tst rsults In Fig. 9, th simulation rsults wr compard with th vhicl dynamo tst rsults. It was found that th simulation rsults of MG1 torqu/spd(c, d), MG2 torqu/spd(, f), ngin spd/torqu(g, h), battry SOC(b) and cabin tmpratur(j) wr in good accordanc with th vhicl dynamo tst rsults. Howvr, th ECT(Engin coolant tmpratur)(i) was 32 for simulation and 42 for th tst. This diffrnc coms from th lakag of coolant hatd by th PTC hatr in th tst. battry and th ngin ar both usd to rmain th SOC low limit. In this study, an intgratd nrgy managmnt stratgy(iems) was proposd to control th ngin on/off. Th IEMS was dvlopd by considring not only th powrtrain systm but also th thrmal managmnt systm Th IEMS is composd of 3 controls: 1) Engin on/off control, 2) Driving mod control, 3) PTC hatr powr, coolant valv and th thrmostat control. Figur 6: Comparison btwn th simulation and th tst rsults for CD mod(2) Figur 6: Comparison btwn th simulation and th tst rsults for CD mod(1) 4 Dvlopmnt of th Intgratd Enrgy Managmnt Stratgy 4.1 Intgratd nrgy managmnt stratgy Existing nrgy managmnt stratgy(ems) of th targt PHEV can b dividd into CD mod and th CS mod. In CD mod, battry is mainly usd to driv th vhicl and in CS mod, th Powrtrain systm Thrmal systm Battry Availabl torqu AP Vhicl spd Cabin tmp. Rquir tmp. Coolant tmp. Engin On/Off control Start Battry SOC>SOC_thrsh? Ys EV driving Hatr On? Ys Tcabin < Tstting? Ys Hatr dmandd powr/battry discharging powr*1 > α? Ys Engin On CS mod EV driving Engin On/Off Mod control Engin on Sris mod Powr-split mod Engin off EV#1 mod EV#2 mod Coolant valv and thrmost at control Valv V1 PTC hatr powr control Coolant tmp. Stting tmp. Cabin tmp. PI controllr Valv V2 Thrmostat On/Off PTC hatr rquird powr Figur 7: Intgratd nrgy managmnt stratgy and control signals EVS28 Intrnational Elctric Vhicl Symposium and Exhibition 4

5 Powrtrain systm T Cabin, Battry SOC,% Engin torqu,nm Spd,km/h Engin on/off control Th ngin is turnd on if th battry SOC is highr than SOC_low limit, th cabin tmpratur is lowr than th stting tmpratur and th PTC hatr consums mor than 5% of th battry powr. If not, th ngin is turnd off and th vhicl is drivn undr th EV mod Driving mod control Mod shift maps wr usd in driving mod control as shown in Figur 8. For th ngin off signal, CD mod shift map which consists of EV#1 and EV#2 mods is usd. For th ngin on signal, CS mod shift map which consists of Sris, Powr-split and EV mods is usd. Tabl 3: Simulation condition Itm Spcification Driving mod FTP 72 Initial battry SOC 35% Initial cabin tmpratur 5 Stting tmpratur Comparison of simulation rsults btwn EMS and IEMS 1 P Q (a) SOC>=SOCthrs SOC<SOCthrs Drivshaft torqu Vhicl spd Control signals Fdback signals Drivshaft torqu Vhicl spd CD mod CD mod shift map CS mod CS mod shift map Stat signal Fdback signal Control signal Pdmd Mod_rq (EV#1 or EV#2) Plug-in control uint Pdmd Mod_rq EV#1,EV#2, Sris, Powr-split EV#1 rqust Driving mod rqust Driving mod rqust Pdmd : vhicl powr dmand Mod_rq: driving mod rqust EV#1 mod EV#2 mod EV#1 and EV#2 mod Bp, SOC, Mod_rq Sris and Powrsplit mod SOC, Bp Figur 8: Driving mod shift map and control signals[5] EV#2 rqust SOC,Pdmd, Mod_rq PTC hatr powr, coolant valv and th thrmostat control If th cabin tmpratur is lowr than th stting tmpratur, PI control is usd for PTC hatr powr control. Th coolant valv and th thrmostat control chang according to th ngin on/off signal and coolant tmpratur. 4.2 Comparison btwn EMS and IEMS Simulation condition Simulation rsults of th EMS and th IEMS wr compard(figur 1). Th simulation condition is shown in Tabl 3. Hatr input powr,ww (b) (c) (d) () Tim,sc Figur 9: Comparison btwn EMS and IEMS It is sn from th simulation rsults in Figur 9 that in th IEMS, th ngin is turnd on in th initial driving stag(b) and th battry SOC is not dpltd(c). Th ngin is turnd off at t=226sc(point P) and vhicl is drivn undr th EV mod. In th EMS, th ngin is turnd off in th initial driving stag(b) sinc th battry SOC is highr than SOC_low limit(c). Th ngin is turnd on at EVS28 Intrnational Elctric Vhicl Symposium and Exhibition 5

6 t=595sc(point Q) whn th battry SOC rachs SOC_low limit(c). In Figur 9, it is sn that th IEMS provids 14.8% highr quivalnt ful conomy than that of EMS. EFE(km/l) IEMS EMS Figur 1: Equivalnt ful conomy of EMS and IEMS 5 Conclusion Th intgratd nrgy managmnt stratgy(iems) was proposd by considring th powrtrain and thrmal managmnt systm. To dvlop th IEMS, th intgratd simulator was dvlopd, which is composd of powrtrain simulator and th thrmal managmnt simulator. And it was validatd with th vhicl dynamo tst rsults. Th IEMS consists of 3 controls: 1) Engin on/off control, 2) Driving mod control, 3) PTC hatr powr, coolant valv and th thrmostat control. It is found from th simulation rsults that th quivalnt ful conomy of th IEMS showd th improvd ful conomy compard with th xisting EMS. Acknowldgmnts This work was supportd by Ministry of Trad Industry & Enrgy in Kora, and th Kora Institut for Advancmnt in Tchnology through Ral-Tim Driv Monitoring Systm Dvlopmnt for Automotiv Componnts Dvlopmnt Innovation. Rfrncs [1] Plug-in Hybrid Elctric Vhicls Larn Mor About th Nw Labl, y.gov/fg/labl/larn-mor-phev-labl.shtml, Environmntal Protction Agncy, accssd on 214 [2] H. L, J. Won, C. Cho, M. L, Y. Park, S. Kim and Y. Kim A Study on Prformanc Charactristics of Air Conditioning Systm for GM Volt(PHEV), KSAE confrnc, Vol. 212,. 5, pp , 212 [3] Chvrolt Volt, lctric-car.html, accssd on 213 [4] Foro EV, 7., accssd on 214 [5] C. Ma, J. Kang, W. Choi, M. Song, J. Ji and H. Kim, A Comparativ Study on th Powr Charactristics and Control Stratgis for Plug-in Hybrid Elctric Vhicls, Intrnational Journal of Automotiv Tchnology, Vol. 13,. 3, pp , 212 Authors Hjin Shin rcivd B.S. and M.S. dgr in mchanical nginring from Sungkyunkwan Univrsity, Suwon, Kora, in 213 and 215. Hr rsarch intrsts includ th modling, dsign, and mbddd systms for lctric vhicls and hybrid lctric vhicls. Sinc 215, sh has workd as an nginr in Hyundai Motor Company. Sunyoung Park rcivd B.S. dgr in mchanical nginring from Sungkyunkwan Univrsity, Suwon, Kora, in 214, whr sh has bn working toward th M.S. dgr. Hr rsarch intrsts includ th powrtrain systm, control stratgy of lctric vhicls, hybrid lctric vhicls and plug-in hybrid lctric vhicls. Jamyoung Pi rcivd B.S. dgr in mchanical nginring from Sungkyunkwan Univrsity, Suwon, Kora, in 214, whr h has bn working toward th M.S. dgr. His rsarch intrsts includ th dsign and control of hybrid lctric vhicl. Jingyu Choi rcivd th B.S. dgr in mchanical nginring from Sungkyunkwan Univrsity, Suwon, Kora, in 212, whr h has bn working toward th M.S. dgr. His rsarch intrsts includ th control of th powrtrain systm for Plug-in hybrid lctric vhicl, and HMT. Sulgi L rcivd B.S. and M.S. dgr in mchanical nginring from Sungkyunkwan Univrsity, Suwon, Kora, in 213 and 215. His rsarch intrsts includ th powrtrain systm, control stratgy of lctric vhicls, hybrid lctric EVS28 Intrnational Elctric Vhicl Symposium and Exhibition 6

7 vhicls and plug-in hybrid lctric vhicls. Sinc 215, h has workd as an nginr in Hyundai Motor Company. Inbom Yang rcivd a Ph.D. dgr in control and instrumntation nginring from th Kora Univrsity, Soul, Kora. H is th ladr of th Smart Vhicl Tchnology R&D Division Kora Automotiv Tchnology Institut. His main rsarch intrsts includ intllignt control systm and control algorithms of hybrid lctric vhicls. Hyunsoo Kim rcivd a Ph.D. dgr in mchanical nginring from th Univrsity of Txas at Austin, Txas, USA, in Sinc 1986, h has workd as a Profssor at Sungkyunkwan Univrsity. His main rsarch intrsts includ transmission systm dsign, rgnrativ braking, powr-distribution algorithms, vhicl stability control for hybrid lctric vhicl and In-whl Elctric Vhicls. EVS28 Intrnational Elctric Vhicl Symposium and Exhibition 7