Evaluation on Economic Performance Efficiency of Hybrid Electric Vehicle

Transcription

1 Proceedigs of the 8th Iteratioal Coferece o Iovatio & Maagemet 67 Evaluatio o Ecoomic Performace Efficiecy of Hybrid Electric Vehicle Rua Xiajig, Yag Qig 2 School of Medical Busiess, Guagdog Pharmaceutical Uiversity, Guagzhou, P.R.Chia, School of Maagemet, Wuha Uiversity of Techology, Wuha, P.R.Chia, ( rxj98@63.com, yagq@whut.edu.c) Abstract: Hybrid electric vehicle is the most mature area i the developmet of ew eergy automotive idustry. This paper employs data evelopmet aalysis model to aalyze the overall ecoomic performace, pure techology efficiecy ad pure scale efficiecy of the five typical hybrid vehicles i Chiese market, ad the obtais the improvig directio of DEA efficiecy. Fially, evaluatio results are offered o the ecoomic performace of hybrid vehicles to raise appropriate suggestios. Key words: HEV; Ecoomic performace; DEA Itroductio The ew eergy automobile has good eergy coservatio ad evirometal protectio effect, which may brig log-term beefit to cosumers ad the society. Moreover, govermets issue subsidy to the cosumers to stimulate market demad for the ew eergy automobiles. Japaese govermet subsidy amouts to about 2000 US dollars to each ew eergy automobile o average, ad America subsidy varies from 500 US dollars to 2000 US dollars. "Tetative Method of the Admiistratio of the Fud Subsidizig Eergy Coservatio ad New Eergy Automobile" released i Chia recetly also explicitly stipulates that Chia will subsidize ew eergy vehicle []. For all this, compared with the traditioal fuel automobile, high price of the ew eergy automobile eables the majority cosumers oly to keep at a respectful distace to it, makig the ew eergy auto market game o oe played. What auto buyers care most is its ecoomical serviceability, rather tha whether it s eergy-savig or ot. So the superiority of the ew eergy automobile ofte caot obtai cosumer's approval. I the curret techical coditios, there is a big gap betwee the ecoomical efficiecy of the ew eergy car ad market expectatios. Its market share is still very low, for example, i 2006, the sales of the ew eergy vehicle accouted for oly 7.9% of total car sales i the Uited States where the ew eergy vehicles develop better, while i Chia less tha %. But the ew eergy vehicle techology cotiues to be mature ad idustry scale expads, its ecoomical efficiecy will ievitably be greatly improved. I recet years, for the aim of aalyzig the power ad ecoomic of hybrid electric vehicle, some scholars has studied the ecoomical evaluatio cosistig of the curret situatio of the maufacture, sale, ad prospect, as well as ecoomical aalysis ad gai ad loss aalysis of hybrid vehicle i Chia [2], ad some has aalyzed ad predicted the life cycle cost of HEV i the last three stages, ad also compared the cost of HEV with that of the covetioal diesel bus (CDB) [3]. They all put forward may iovative viewpoits. Nevertheless, research limitatios are still exists because of all these researches are still at the exploratio stage. Based o the results of other scholars, this paper aalyzes the ecoomical efficiecy of the typical hybrid electric vehicles by usig data evelopmet aalysis model to estimate the overall ecoomic performace, pure techology efficiecy ad pure scale efficiecy of the five typical hybrid electric vehicles i Chiese market, so obtaiig the improvig directio of DEA efficiecy. Fially, evaluatio results were aalyzed o the ecoomic performace of hybrid vehicles to raise appropriate suggestios. This paper is divided ito four parts: Part I, Itroductio; Part II, Models ad Idicators; Part III, Data ad Results Aalysis; Part IV, Coclusio. 2 Models ad Idicators 2. Model desig Data evelopmet aalysis, based o the actual decisio makig uit of a productio system, is built o the cocept of "Pareto optimal" of decisio makig uits. It determies the efficiecy frotier of the productio system (or frotier productio fuctio) through the use of liear programmig techiques, ad the gets the relative efficiecy as well as scale beefit of decisio makig uits ad other iformatio. For decades i foreig coutries, there are a great deal of the research literature of DEA theory ad its applicatio i maagemet sciece ad i the field of operatios research [4-6]. Chiese scholar Wei Qualig playes a active ad importat role i the popularizatio ad promotio

2 68 Proceedigs of the 8th Iteratioal Coferece o Iovatio & Maagemet of DEA i Chia [7] ad i 2000 he published literature o the research progress of DEA [8]. I this paper, the ecoomic performace of the hybrid electric cars ca be see as the activity of producig a certai umber of "products" by some decisio-makig uits through the iput of a umber of productio factors. Although the cocrete cotet of iputs ad outputs is somewhat differet, its purpose is to maximize the ecoomic ad social beefits as much as possible. Therefore, firstly, the text usesc 2 R model with a o-archimedea ifiitesimal evaluatig DMU overall efficiecy based o the iput. T T + mi[ θ ε( es ˆ + es)], λjxj + s = θx0, j= + ( D ) λ jyj s y0, ε = j= λ j 0, j =,,, + s 0, s 0. ε is o-archimedea ifiitesimal () The overall efficiecy used to evaluate techology ad scale is called the overall efficiecy. 2 Secodly, the text uses BC model with a o-archimedea ifiitesimal evaluatig DMU pure techological efficiecy based o the iput. T T + mi[ σ ε( es ˆ + es)], λjxj + s = σx0, j= + (2) λ jyj s = y0, ( Dε ) j= λj =, λj 0, j =,,, j= + s 0, s 0. ε is o-archimedea ifiitesimal The DMU efficiecy calculated by the model is pure techical efficiecy, reflectig the coditios of DMU pure techical efficiecy. Fially, it calculates the et scale efficiecies of DMU by formula (3). θ σ s = (3) 2.2 Selectio of idicators ad aalysis Hybrid cars use both fuel ad electric drive. Accordig to the proportio of electric drive, it ca be divided ito low degree hybrid, moderate degree hybrid ad high degree hybrid. The oil savig rate of low degree hybrid vehicles is betwee 0% -5%. The cost of which is low ad the techology is easy to implemet. Typical car models home ad abroad are Mercedes-Bez Smart, Chery A5 BSG, Bestur B50 HEV, etc.; the oil savig rate of high degree hybrid vehicles is betwee30%-40%. The cost of which is high ad the structure is complex. Typical car models are Mercedes-Bez S400 Hybrid, Toyota Prius, BYD F3 DM. Moderate fuel-efficiet hybrid vehicles are betwee the two i terms of oil-savig, cost ad techology. Typical examples are Buick LaCrosse ECO-Hybrid, Hoda Civic Hybrid, Jujie Hybrid etc.

3 Proceedigs of the 8th Iteratioal Coferece o Iovatio & Maagemet 69 This paper selects 5 hybrid cars for sale o Chiese market sales, respectively, Toyota Prius, Civic Hybrid, LaCrosse ECO-Hybrid, BYD F3 DM ad Chery A5 BSG, coverig low degree hybrid, moderate degree hybrid ad high degree hybrid. They are of both foreig ad domestic brads, ad very typical. The aalysis of their ecoomic performace ca fully reflect the ecoomic performace ad other coditios of hybrid vehicles. From the etire life-cycle perspective, the cost of hybrid vehicles is maily the purchase cost ad the use cost. For cosumers, the purchase cost of hybrid cars is the purchase price, while the use cost icludes: fuel costs, maiteace costs, tax costs ad govermet subsidies costs, of which tax ad govermet subsidies costs ca be eglected, ad maiteace costs deped o the specific vehicle coditio which has great radomess ad is difficult to have a uified measure. Therefore, the fuel cost is the mai cocer of the use costs of hybrid cars. Cosiderig the above aalysis, the paper decided to choose the followig five techical ad ecoomic idicators: price, emissios, fuel cosumptio, oil savig rates ad sales of hybrid vehicles to coduct ecoomic aalysis, as is show i Table. Table The Ecoomic Idicators of the 5 Hybrid Electric Vehicles Hybrid vehicles Price (0,000 yua) Emissios (L) Fuel cosumptio (L/00km) Savig rate (%) Sales (Uits) Toyota Prius Civic Hybrid Lacrosse ECO-Hybrid BYD F3 DM Chery A5 BSG Selected 5 from the price of hybrid view, which, BYD F3 DM ad Chery A5 BSG Both the price of domestic brad cars less tha 5 millio, the price of Chery A5 BSG is less tha 0 millio, was 7.48 millio. While the other three models priced foreig brads are i betwee 250,000 to 300,000 yua, domestic hybrid vehicle compared to the foreig price of hybrid vehicles more obvious advatages. From the displacemet poit of view, LaCrosse ECO-Hybrid displacemet of 2.4L, 4 other models i the.0-2.0l displacemet betwee the emissio models are moderate. At the same time, vehicle emissios largely determie how much of its fuel from the fuel cosumptio idicators, LaCrosse ECO-Hybrid's fuel cosumptio is oe hudred kilometers 8.3L, Chery A5 BSG's oe hudred km fuel cosumptio of 5.2 L, Toyota Prius, the Civic Hybrid, BYD F3 DM of hudred kilometers are betwee the 4L-5L. Savig rate of this idicator reflects the geeral hybrid cars ad similar vehicles compared to the ratio of the fuel savigs, depedig o the electric drive hybrid vehicle techology. At the same time, this idicator is strog by mixig, the mixig, weak mixig three types of hybrid vehicles stadards. Toyota Prius, BYD F3 DM models of fuel-efficiet mixig of two strog rate of more tha 30%; Civic Hybrid, LaCrosse ECO-Hybrid's fuel-efficiet models i the mixed two rates were 6.3%, 5%; Chery A5 BSG's savig rate of 0%, mixed models are weak. Sales reflected the market's level of demad for hybrid vehicles, from 5 models of domestic sales situatio of Chia; its sales are very small. Amog them, the sales of the Toyota Prius are the best, listed i the domestic market i early years, sales of just over three years sice 3000, ad just listed BYD F3 DM, its sales volume i the Shezhe Muicipal Govermet procuremet 80, very few real market sales. 3 Data ad Results Aalysis Accordig to the idicates ad data of table, by usig C 2 2 R model ad BC model, it calculates five types of ew eergy (hybrid electric) vehicles ecoomic total efficiecy θ, pure techical efficiecyσ, ad pure scale efficiecy s calculated by formula (3) ad the cocrete results will be show i table 2.

4 70 Proceedigs of the 8th Iteratioal Coferece o Iovatio & Maagemet Table 2 The DEA Ecoomic Performace Evaluatio Results of Five Types Hybrid Electric Vehicles DMU + Scale θ σ s s s 2 s 3 s 4 s efficiecy Toyota prius uchaged Civic Hybrid icreasig Lacrosse ECO- Hybrid icreasig Byd F3 DM icreasig Chery A5 BSG icreasig The s s s s ad s of table 2 are the umerical values of slack variables respectively which forms uder the costraits of C 2 R model amely type. Uder the coditio of existig properties ad cofiguratio of the five types of hybrid electric vehicle, Toyota prius is i the forefrot of ecoomic performace efficiecy. This model is itegrated DEA efficiet i terms of ecoomic performace. It is techically efficiet, that is, has reached the maximum output i terms of relative ivestmet, with the decisio-makig uits i the curve of the productio fuctio. It is also effective i terms of scale, that is, the iput volume is either too large or too small, with returs ragig from icreasig to decreasig, which are i the best coditio. The ecoomic performace of the hybrid electric vehicle is characterized by: the use of gasolie egie ad electric motor to power the vehicle. The workig priciple of the electric motor is to covert the kietic eergy ito electrical eergy through the motor whe the vehicle decelerates, ad store i the ickel-metal hydride battery ad release agai whe startig or speedig up so as to reduce the load o the egie. The egie will automatically shut dow whe stops so as to save fuel. Toyota prius adopts.5 L VVT-i egie ad electric motor, the ickel-metal hydride battery ad power cotrol uit ad so o to compose the secod- geeratio of Toyota hybrid system (THS), usig differet dyamic combiatio i differet drivig coditios. The maximum power ad the maximum torque of the egie are 57 kw/4500 RPM ad 5 m/4200 RPM respectively, ad the risig power ad special power are 38.08kW/L ad kW/Kg respectively. The power ad torque of the electric motor are 50 kw/ rpm ad 400 m/0-200 rpm. The series of volts cuboid chlorie hydrogeated metal battery forms a volume of 274 volts cuboid compact battery pack. The maximum speed is 65 km/h. Ad the 53 kw of the.5 liters petrol egie power ad 50 kw power of the electric motor produce the output of the total power of 06 kw. With the full load up to 750 Kg, the power of the Prius is ot very strog, but the output torque of the mixed power of Toyota Prius is quite amazig. Although i order to be fuel savig ad evirometal protectig, its egie ad electric motor will ot output the maximum torque. But due to the motor s 400 m output torque is betwee RPM, it is eough to make the Prius have a better ability to accelerate. O the other had, hybrid electric vehicle with pure techical efficiecy i the frot of the ecoomic performace are civic Hybrid, Byd F3 DM ad Chery A5 BSG. These three models belog to pure techical DEA effectiveess ad the output has reached the maximum i terms of iput. The decisio-makig uits are located i the curve of the productio fuctio, while the scale returs are ot i the best state of costat scale returs. These three vehicle models have commo characteristics i the ecoomic performace. The thesis will take civic Hybrid as a example, by comparative aalysis with Toyota Prius to illustrate the characteristics of such vehicles. Hoda civic Hybrid adopts the Secod-geeratio Hybrid Electric System which composes of.3l level-3 i-vtec egie ad IMA (electric motor auxiliary system), electric motor, ickel-metal hydride batteries ad power cotrol uits ad so o. Accordig to the vehicle s drivig coditio, level-3 i-vtec (cylider stop system) ca be divided ito low speed, high speed ad cylider stop three-stage cotrollig valve; whe the vehicle is i low ad costat speed, all cyliders will stop workig, with oly electric motor providig drivig force; whe i urget acceleratio, high-speed cocave wheels ca achieve high power output, while all cylider will stop whe deceleratig. The maximum output power of the egie is 7.5KW, maximum output torque is 70m, risig power is 55kw ad the power of the electric motor is 5kw. Combied together, the whole system ca reach the same power output ad torque output as that from.8l gasolie egie. Hoda civic Hybrid adopts cylidrical ickel-metal hydride rechargeable batteries, ad

5 Proceedigs of the 8th Iteratioal Coferece o Iovatio & Maagemet 7 the voltage ca be up to 58V, which esures the output power 6KW so as to drive the electric motor with power of 5KW. To save the fuel, Hoda civic hybrid has give up a quick acceleratio ad its maximum output power of the hybrid power system is 86.5KW, maximum torque output is 70m, all of which are much lower tha Toyota Prius. Eve if compared with the.8l gasolie versio with maximum power ad the maximum torque beig 03KW/6300RPM ad 74m/4300RPM respectively, the power of Hoda civic Hybrid is much iferior, obviously week. Hoda Civic Hybrid's acceleratig ability has declied tha the Hoda Civic with.8l, the acceleratio capabilities of which are similar with the Toyota Prius. Hoda Civic Hybrid's acceleratio is obviously weak compared with Toyota Prius. I the aspect of suspesio,toyota Prius has adopted McPherso frot suspesio ad trailig arm torsio beam rear suspesio, while Hoda civic Hybrid still uses McPherso ad re-adjusts the positioal agle ad multi-lik double wishboe rear suspesio,improvig the rear suspesio shock absorber s istallatio positio of the vehicle which ameliorates the athletic performace of the vehicle. I oil cosumptio, Toyota Prius ca save more oil tha Hoda Civic Hybrid which is the purpose of Hybrid power vehicles. The maufacturer calibratio of the r fuel cosumptio of Toyota Prius ad Hoda Civic Hybrid are 4.3 liters ad 4.6 liters respectively, which are very ecoomical. However, the Hoda Civic Hybrid uses a relatively simple techology to achieve low fuel cosumptio whe compared with Toyota Prius. It cosumes oly 0.3 liter more oil every oe hudred kilometer tha Toyota Prius which possesses complex power system, which idicates its brilliat respect. I additio, Hoda Civic Hybrid s hybrid power techological level is lower tha Toyota Prius, so is the cost, due to its slight distictio with the curret covetioal power vehicles, with oly additioal batteries ad electric motors. The utilizig cost will be high with the higher scietific ad techological level of the products, which are the causes why foreig cosumers will be hesitat to buy Toyota Prius. Toyota Prius ad Hoda Civic Hybrid fuel cosumptio cotrast will be elaborated i table 3. Table 3 Fuel Cosumptio Cotrast Betwee Toyota Prius ad Hoda Civic Hybrid Fuel cosumptio test cotrast (L/00KM) Toyota Prius Hoda Civic Hybrid The AMS stadard test field highway Ordiary highways Urba road Itegrated oil cosumptio No-DEA effective DMU s projectio o the productio forefrot is DEA effective which meas through the appropriate adjustmets of iput ad output umerical of o-dea effective DMU to achieve DEA effectiveess. Accordig to this theory, the author ca get the improvemet directio of the ecoomic performace of the five types hybrid electric vehicles which will be show i table 4. Table 4 Five Types Hybrid Vehicles Improvemet Directio of Ecoomic Efficiecy Improvemet Directio DMU Y X 0 0 Toyota prius (27.980,.500,4.300,3.300) ( ) Civic Hybrid (26.980,.300,4.700,6.300) ( ) Lacrosse ECO-Hybrid (7.920,.598,5.8,0.458) (33.000) Byd F3 DM (4.980,.000,4.000,33.000) (7.000) Chery A5 BSG (7.480,.600,5.200,0.000) ( ) Accordig to table ad table 4, i the five types hybrid electric vehicles, Lacrosse Eco-Hybrid model belogs to ecoomic performace o-dea effectiveess (overall). It helps to fid the ascedig directio of ecoomic performace. To take Lacrosse Eco-Hybrid as a example, its ecoomic X performace of projectio poits i productio forefrot is 0 =(7.920,.598,5.8,0.458), Y 0 = (33.000), all of which show that i order to achieve ecoomic performace (based o the iput of the

6 72 Proceedigs of the 8th Iteratioal Coferece o Iovatio & Maagemet C 2 R model), uder the coditio of maitaiig the output idex ad sales value of 33,000, cuttig its correspodig iput value, amely the price reduced to 7.920, gas emissio reduced to.598, fuel savig rate reduced to I additio, table 2 has show five types hybrid electric vehicles scale returs of ecoomic performace, with oe of the types scale returs remai the ivariable stage, while other four types keep icreasig, amely all the five types keep a uchaged or icreasig state, all of which show that every type ew eergy hybrid power vehicle has a strog mometum of developmet at preset. They are still i the stage of cultivatio ad growth. O the coditio of avoidig oe-side developmet of ecoomic improvemet, most of the hybrid electric vehicles ca have proper expasio to make further improvemet of each ecoomic performace. 4 Coclusio Data evelopmet aalysis is the effective meas to coduct a comparative aalysis of ecoomic performace of hybrid vehicles. The method ca determie the frotier of experiece productio, give the DMU overall efficiecy, pure techical efficiecy, pure scale efficiecy, the DMU projectio o productio frotier, ad at the same ca determie the scale of the situatio, provide a wealth of system aalysis tools, provide decisio-makers with efficiecy evaluatio, quatitative maagemet iformatio of scale ad other aspects of aalysis, makig decisio-makig more scietific ad reliable. Data evelopmet aalysis is the effective meas to coduct a comparative aalysis of ecoomic performace of hybrid vehicles. The method ca determie the frotier of experiece productio, give the DMU overall efficiecy, pure techical efficiecy, pure scale efficiecy, the DMU projectio o productio frotier, ad at the same ca determie the scale of the situatio, providig a wealth of system aalysis tools, make decisio-makers with efficiecy evaluatio, quatitative maagemet iformatio of scale ad other aspects of aalysis, makig decisio-makig more scietific ad reliable. Refereces [] Li Jiji. Thoughts ad Recommedatios o Chia's New Eergy Automotive Idustry[J]. Idustrial Techology ad Ecoomy, 2008,():6-8 (I Chiese) [2] Su Zhiju, etal. Aalysis from Techique ad Ecoomy of Developig Hybrid Vehicle Idustry i Chia[J]. Joural of Tiaji Uiversity (Social Scieces), 2007,(5): (I Chiese) [3] Qi Tiayu, etal. The Ecoomic Aalysis of the Developmet of HEV Bus i Chia[J]. Chia Soft Sciece, 2009,(S):02-06 (I Chiese) [4] Tofallis C. Iput Efficiecy Profilig: A Applicatio to Airlies [J]. Computers & Operatios Research, 997,24(3): [5] Grosskopf S, etal. Aticipatig the Cosequeces of School Reform: A ew use of DEA[J]. Maagemet Sciece, 999,45(4): [6] Kao C. Measurig the Efficiecy of Forest Districts with Multiple Workig Circles[J]. Joural of the Operatioal Research Society, 998,(49): [7] Wei Quali. Evaluatio o the Relative Effectiveess of the DEA Method - New Areas of Operatios Research[M]. Beijig: Chia Remi Uiversity Press, 988 (I Chiese) [8] Wei Quali. Data Evelopmet Aalysis (DEA)[J]. Sciece Bulleti, 2000,(7): (I Chiese)