关于新能源汽车的外文文献

1、multi-sources model and control algorithm of an energy management system for light electric vehicles m.a. hannan a, f.a. azidina,b, a. mohameda adept. of electrical, electronic fax: +60 3 89216146. e-mail addresses: hannaneng.ukm.my (m.a. hannan), faridarafatmail2.ukm. my (f.a. azidin), azaheng.ukm.

2、my (a. mohamed). energy conversion and management 62 (2012) 123130 contents lists available at sciverse sciencedirect energy conversion and management journal homepage: subsidized rate of petrol ron 95. the subsidy is us$ 0.18 per liter and the tax free is us$ 0.22 from the market price of us$ 1.00

3、19. if average one motorcycle uses half liter petrol per day, the govern- ment spends approximately us$ 1 million each day. however, the selling of motorcycle is expanding each year at nearly 200,000 units with increment of 5% per year 20,21. thus, subsidization does not help to improve living quali

4、ty due to toxic emission in the city. however, with the awareness and less subsidized solar park energy harvesting could be constructed as explained in sec- tion 2.4. plug-in solar energy harvesting is not only offer green environment but also a good strategy for low income people to have free energ

5、y. international energy agency, forecast the world oil demand and supply between 1998 and the projection of 2026 as shown in fig. 1 1. it is seen that the oil demand is increasing proportionately and the oil supply is decreasing from 2014, respec- tively. the increase of oil price forces the governm

6、ent to fi nd other alternative way of transportation or to face double of subsidization for next 10 years. in order to meet the consumers requirement such as power, longer travel distance and reliability, ems and available stored en- ergy lev need to be design. this paper presents a three-wheel lev

7、system in which a battery is used as the primary source of energy, while the sc is used as the auxiliary energy source, and the fc is used as an extended energy source for a high demand load. in addi- tion of multi-sources, the battery can be charged at home and in the solar park by harvesting solar

8、 energy. thus, the control strategy in the ems plays an important role: it either enhances the storage capacity or changes the energy sources, as required. table 1 summaries of the hybrid vehicles parameters and technologies. no.vehicle description research technologyrenewable energy operating volta

9、ge power load effi ciency (%) ref. 1hev-auto richshaw proposed four different drive train: direct drive, one electric motor, parallel hybrid confi guration, conventional with solar assist solar, battery48 v57 kw77 e 73 m 3 2vehicular application power sharing fc and sc with control algorithm. pi con

10、troller to improve power converter system fc/sc188 v58 kwbetter es23 3hybrid power generation simulation power generation with electrolyze and hydrogen storage tankwind/fc/sc400 v110 k wbetter es6 4hev-icevehicle equipped by planetary gear and control strategies with serial/ parallel/(s/p) hev overv

11、iew battery300 v50 kw-em540 fe9 5fcvsimulate fc scooter with application of foc control systemfc, battery250 kwimproved es 13 10hevsolar/hydrogen hybrid power system combining battery/fc for hevbattery, sc, fc, solar 42 v15 kwbetter es7 11hevinvestigating fc and sc based on electric bicyclefc, sc36

12、v300 w45 fc17 12hevems in solar car racesolar, battery300 v3.5 kw91 em8 13evems in directly-drive vehiclebattery, sc48 v1.85 kw7016 14hevhev in virtual test bed environmentbattery, fc, sc250 v50 kwimproved es 14 15hevcontrol strategy in power management with various converter topologybattery, sc?270

13、 v216 kwbetter e, es 12 16automotive application study on hybridization of battery/fc/scbattery, fc, sc42 v10 kwhigh es2 17hev-ice analysis of drive train effi ciencybattery?300 v41 kw ice 75 kw em better m, es 10 e electrical, m mechanical, fe fuel economy, cs cost saving, es energy saving. fig. 1.

14、 oil price forecasting based on demand and supply. control algorithm motor drive fc energy management system (ems) batterysc fig. 2. multiple power sources in a closed loop motor drive system for a three- wheel lev. 124m.a. hannan et al./energy conversion and management 62 (2012) 123130 2. energy so

15、urce models there are three sources of energy models used in the three- wheel lev systems: batteries, scs and fcs as shown in fig. 2. detail energy model are explained as follows. 2.1. battery model a lead-acid battery model is used for electric vehicle. dimension of the battery is set to have 24 v

16、supply voltage and 48 ah storage capacities that can support 1000 wh for a maximum charge. that mean the vehicle could travel around 10 km for a single charge. theequivalentcircuitofthebatterymodelproposedby matlab/simulink can be expressed as in 22 as follows. vbatt v0? k q q ? it ae?b?it3 where vb

17、attis constant load voltage and v0is no load voltage, k is the polarized voltage constant, q is the battery capacity, a is the exponential voltage and ?b is the exponential capacity of the bat- tery. the load current i and time t is parameterized, respectively. the eq. (3) can be related to battery

18、state of charge (soc) which is presented in 5,22,23 as follows. vbatt v0? k soc aebqsoc?14 where soc is measured as battery state of charge per unit value. the energy discharge from battery can be calculated from soc as follows. e v0q1 ? soc ? kq1 1 soc ? aq1 ? socebqsoc?15 the battery is discharge

19、until the soc is at 50% and then fc will be switch on. the soc level should be high enough since the startup for fc may take from seconds to several minutes. when the fc is in full operation, battery supply is cut off. battery will be only in action when fc has problem during transient energy demand

20、 and response. 2.2. fuel cell model the fc model is designed in 24,25 applied for lev. the fc is powered by 6 kw and 45 v voltage supply. the relative high power 6 kw fc is chosen to support fast and large variations of load cur- rent. the disadvantages are the higher price and heavier due to large

21、membrane cell and the storage of hydrogen tank. the poten- tial voltage v produced by the fuel cell is described as follows. v voc? navlnifc6 where, vocis the open circuit voltage, n is the numbers of the cell, avis the exponential voltage, ifcis the fuel cell current, and ln is nat- ural logarithm.

22、 the eq. (6) is related to empirical model which de- scribes precisely details of the current/voltage of the pemfc in 25 as follows. v ve? ir ? aln i in io ? meni7 where vegenerated voltage of a single cell, i is current density, inis fuel crossover current density, iois exchange current density at

23、an electrode/electrolyte interface, a is coeffi cient in natural logarithm form of tafel equation, r electric resistance per unit area and m, n are constant. the energy delivered by fc in one drive cycle can be related to eq. (6) is described as follows. efc z v fc ?ifcdt8 where efcgenerated voltage

24、 of a single cell. the fc is connected to the power diode to avoid reverse current fl ow to the system in the regenerative situation and linked to the dc/dc converter to maintain a constant load voltage. 2.3. super-capacitor model the sc energy storage system is designed to aid the battery or fc whe

25、n there is high demand for power in the vehicle. the mod- eling of sc is related to the basic discharging circuit of the capacitor voltage in terms of the resistor and capacitor, rc circuit. the effec- tive discharging voltage depends on the initial voltage of the capac- itor and the rc time constan

26、t, which is described in 26 as follows: vsct vie ?t rc 9 where vscis sc voltage and viis initial voltage the amount of energy delivered by the sc is directly propor- tional to the capacitance and voltage changes throughout dis- charge defi ned in 27 as follows: e 1 2 cv2 i ? v2 f 10 where vf is fi n

27、al voltage and c is capacitor value a number of scs are arranged in series and parallel to provide a certain amount of energy during acceleration and peak load de- mand. the total resistance rtotaland capacitance ctotalof the sc module is calculated in 28,29 as follows: rtotal ns esr np 11 ctotal np

28、 c ns 12 where nsis number of capacitors in series, npnumber of capacitors in parallel and esr is equivalent series resistance. by the eqs. (9) (11), the sc module dimension is designed to having 13.5 v and 40 f. the total energy at the half-voltage is about 2500 ws (j). it is enough to support if o

29、ther sources losing power in time. 2.4. energy harvesting for recharging the objective energy harvesting is the use of maximum renew- able energy for zero toxic emissions and non-fossil fuel vehicle. in the developed system, the battery, sc and fc are used as primary, auxiliary and extended sources

30、of energy. the sources are applied whenever needed, especially for lnhigher demand of load. how- ever, regenerative braking and variety refueling is hard to imple- ment in the system. thus, energy harvesting from solar car park or plug-in system is created for battery recharging or refueling. accord

31、ingly, 46 m2space can be estimated for solar panels. in malaysia, it is estimated that 1 m2solar panel can generate solar energy with effi ciency of 13% 20. the solar harvesting energy can be derived as follows. esolar z t1 t2 ?0:08t 64:1dt13 where esolaris solar energy harvested in 1 day, t1and t2a

32、re the start and stop time of energy harvesting. if the duration of solar charge begin from 9.00 to 17:00, total energy that can be obtained by solar panel for a single solar car park is roughly 10002000 wh (3.6 7.2 ? 106j). converting this solar energy,desolarto the distance tra- vel by vehicle dve

33、h, can be estimated as follows. m.a. hannan et al./energy conversion and management 62 (2012) 123130125 dveh gdesolar fte 14 whereg is electric vehicle effi ciency and fteis traction effort force. the amount collecting energy from solar for 8 h is 1000 wh for a lev is possible. with the parameter of

34、 lev which has a total mass 200 kg including passenger, velocity of 50 km/h and acceleration of 1 ms?2, the estimation travel distance is around 10 km. fig. 3 shows the various vehicle loads and the distance the vehicle could travel depend on energy in wh. the maximum solar energy that can be harves

35、ting for a car is up to 2000 wh per day. for a lev, it can be calculated that half of the solar car park is required. fig. 3 also shows the optimal sizing of vehicle which is below 600 kg i.e., lev. thus, developed vehicle system uses the maximum harvesting energy which is fuel cost effective than t

36、hat of conven- tional engine vehicle. 3. energy management system (ems) the ems controls all of the energy sources that have different tasks in delivering power to the load. the battery is the main energy source of the vehicle. once the start button is triggered, processors determine the battery cap

37、acity and the pedal accelera- tion. then, the ems determines which energy sources should be activated. the fc is the secondary energy source, starts supplying energy to the load and recharges the battery when the battery capacity is below 50%, in consideration of start time of fc which take a few mi

38、nutes. if the battery reaches 80% of its capacity, the fc supply is cut off. any excess energy from the fc is stored in the battery. the sc supports energy sources when both the battery and fc take a longer time to support high power demands. after the ems has been triggered, it recharges and waits

39、for the next re- quest. the control strategies of the ems are depending on rule- based feedback the control parameters. the feedback control parameters such as the acceleration pedal (po), battery soc (bc) and vehicle speed (pd) are used to control activation of multi- sources of battery, fc and sc,

40、 respectively. all the control switches follow the rules that have been described in control algorithm. 3.1. control algorithm a control algorithm is designed to fulfi ll the condition based on the situation and to maximize energy conservation. the opera- tional control strategies are based on the s

41、even operation states. the main task of the system is to maintain the power source to drive the dc motor. the controller determines three basic opera- tional input conditions: pedal offset (po) and power duration load (pd) are determined by measuring motor speed over a long period of time, and batte

42、ry capacity (bc). the control algorithm is defi ned by the control states in the logic combination shown in table 2. based on the source conditions, the seven operational states are as follows: state 1: (input: safety button): off operation/safety features. state 2: (input: bc + /pd + /po): battery

43、is fully used to drive the motor if there is no high power demand. part of the energy is conserved; the fc stays in operation and is active when the battery charge is low. state 3: (input: /bc + /pd + /po): fc takes over to drive the vehi- cle and charge the battery until it turns to state 2. state

44、4: (input: bc + pd + /po): the consequence of a high power demand forces the system to activate the fc as the aux- iliary energy source. state 5: (input: bc + /pd + po): in this situation, the battery-pow- ered vehicle accelerates with the support of the sc. the vehicle then turns to state 2 after a

45、ll energy in the sc is used. state 6: (input: /bc + /pd + po): the battery is critical. the fc- powered vehicle accelerates with additional energy from the sc. after the sc tank is empty, the system changes to state 3. state 7: (input: bc + pd + po): as the vehicle moves into high speed and requires

46、 acceleration, the system is forced to activate all of its energy sources. in this system, the fc operates in the on/off position, which means that the energy from the fc is supplied to the load in full operation. the system attempts to manage the operation of the en- ergy sources based on the opera

47、tional control strategy. 4. vehicle system the vehicle system assembled with lev simulation model as shown in fig. 4. the vehicle system consists of feedback and con- trol system, multi-sources, ems and power control, dc machine and vehicle load. the feedback and control system block detect feedback

48、 measurement such as pedal acceleration, battery soc and vehicle speed and then convert into digital signal to ems block. the ems block will make decision from the input data based on control algorithm to set the sources and control the current supply to dc machine according to the reference speed (

49、ece-47 drive cy- cle). in the dc machine block consist of dc motor rated 120 v, 2.2 kw. in order to have better effi ciency of dc machine in electric vehicle, a higher rated voltage is recommended 30,31. all param- eter of the forces exerted to the vehicle are in the vehicle load block. then the act

50、ual speed is compared to the reference speed of ece-47 drive cycle. 4.1. power control system before link to multi-switches, all energy sources are connected to the dc converter to raise the source voltage to rated voltage for dc machine. then they are linked to the multi-switches which contain a po

51、wer control switch that allow current fl ow when it is activated. switch activation depends on the input from pedal accel- eration (po), battery soc (bc) and high power demand load (pd). the detailed system that controls the switches and the current for the vehicle power load is shown in fig. 5. the

52、 outputs current i.e., supply current is the combination of currents from the battery, the fc and the sc sources. the current controlled source includes a pi controller that determines the reference current from the mea- suring actual speed and the reference speed of the vehicle 23. 05001000 1500 20

53、00 2500 3000 3500 4000 45005000 0 10 20 30 40 50 60 distance (km) energy (wh) vehicle load 200kg vehicle load 600kg vehicle load 1200kg fig. 3. various vehicle loads and the traveling distance of the vehicle against energy in wh. 126m.a. hannan et al./energy conversion and management 62 (2012) 12313

54、0 the reference current is then compared to an armature current to determine the appropriate duty cycle for the dc chopper. the dc chopper provides controlled current from the supply current and duty cycle that have been measured precisely to power the vehicle. in an h-bridge system, the switches ar

55、e used to provide several modes of driving, such as forward drive, reverse drive and motor braking. 4.2. dc machine a separately excited dc machine is implemented in the vehicle system. the same voltage supply is given at the fi eld and the arma- ture terminals. the induced counter electromotive for

56、ce is propor- tional to the constant voltage and the electromechanical torque is proportional to the armature current multiplied by constant torque table 2 logic control algorithm of power sources in various conditions. statesuper-capacitorfuel cellbatterycondition 1000off operation/safety features

57、2001bc is high; pd is low and po is low 3010bc is low; pd is low and po is low 4011bc is high; pd is high and po is low 100 (not possible) 5101bc is high; pd is low and po is high 6110bc is low; pd is low and po is high 7111bc is high; pd is high and po is high po pd bc po pd bc sc_in po v_sc i_sc v

58、_fc i_fc v_batt i_batt v_batt i_batt v_fc i_fc v_sc i_sc bc fc sc current sense in speed vehicle in dc link + dc link - soc out speed out current sense in pelect out soc in dc + dc - speed in pelect in vehicle speed soc pedal acceleration feedback and control system sc/dc-dc booster fc/dc-dc booster

59、 battery/dc-dc booster switches and power control dc machine vehicle system fig. 4. vehicle system simulation in matlab/simulink. current controlled source h-bridge dc-dc chopper actual speed supply current duty cycle load current to dc machine reference speed armature current controlled current control signal pdpobc multi - switches sc/dc converter fc/dc converter battery/dc converter fig. 5. power control system for a three-wheeled lev. m.a. hannan et al./energy conversion and management 62 (2012) 123130127 15,30. to change the dc machine into a dc motor, an i