外文翻譯---混合動力電動汽車機(jī)械和再生制動的整合

1、<p><b>　　外文文獻(xiàn)原稿和譯文</b></p><p><b>　　原 稿</b></p><p>　　Mechanical and Regenerative Braking Integration for a Hybrid Electric Vehicle</p><p><b>　　Abs

2、tract</b></p><p>　　Hybrid electric vehicle technology has become a preferred method for the automotive industry to reduce environmental impact and fuel consumption of their vehicles. Hybrid electric ve

3、hicles accomplish these reductions through the use of multiple propulsion systems, namely an electric motor and internal combustion engine, which allow the elimination of idling, operation of the internal combustion engi

4、ne in a more efficient manner and the use of regenerative braking. However, the added cost of the </p><p>　　A more cost effective design of an electro-hydraulic braking system is presented. The system electr

5、o-mechanically controlled the boost force created by the brake booster independently of the driver braking force and with adequate time response. The system allowed for the blending of the mechanical and regenerative bra

6、king torques in a manner transparent to the driver and allowed for regenerative braking to be conducted efficiently.</p><p>　　A systematic design process was followed, with emphasis placed on demonstrating c

7、onceptual design feasibility and preliminary design functionality using virtual and physical prototyping. The virtual and physical prototypes were then used in combination as a powerful tool to validate and develop the s

8、ystem. The role of prototyping in the design process is presented and discussed.</p><p>　　Through the experiences gained by the author during the design process, it is recommended that students create physic

9、al prototypes to enhance their educational experience. These experiences are evident throughout the thesis presented.</p><p>　　1.1 Modern Hybrid Electric Vehicles</p><p>　　With rising gas prices

10、 and the overwhelming concern for the environment, consumers and the government have forced the automotive industry to start producing more fuel efficient vehicles with less environmental impact. One promising method tha

11、t is currently being implemented is the hybrid electric vehicle.</p><p>　　Hybrid vehicles are defined as vehicles that have two or more power sources [25]. There are a large number of possible variations, bu

12、t the most common layout of hybrid vehicles today combines the power of an internal combustion engine (ICE) with the power of an electric motor and energy storage system (ESS). These vehicles are often referred to as hyb

13、rid electric vehicles (HEV’s) [25]. These two power sources are used in conjunction to optimize the efficiency and performance of the vehicle, whic</p><p>　　Hybrid electric vehicles have the distinct advanta

14、ge of regenerative braking. The electric motor, normally used for propulsion, can be used as a generator to convert kinetic energy of the vehicle back into electrical energy during braking, rather than wasting energy as

15、heat. This electrical energy can then be stored in an ESS (e.g. batteries or ultracapacitors) and later released to propel the vehicle using the electric motor.</p><p>　　This process becomes even more import

16、ant when considering the energy density of batteries compared to gasoline or diesel fuel. Energy density is defined as the amount of energy stored in a system per unit volume or mass [44]. To illustrate this point, 4 kil

17、ograms (4.5 litres) of gasoline will typically give a motor vehicle a range of 50 kilometres. To store the same amount of useful electric energy it requires a lead acid battery with a mass of about 270 kilograms [25]. Th

18、is demonstrates the nee</p><p>　　1.2 Research Scope - Regenerative Braking Systems</p><p>　　The scope of the research presented is to create a low cost regenerative braking system to be used on

19、future economical hybrid vehicles to study the interaction between regenerative and mechanical braking of the system. This system should be able to control the combination of both regenerative and mechanical braking torq

20、ue depending on driver demand and should be able to do so smoothly and safely. Controlling the regenerative braking torque can be done using control algorithms and vector control</p><p>　　2.1 Hybrid Electric

21、 Vehicle Overview</p><p>　　Hybrid vehicles have emerged as one of the short term solutions for reducing vehicle　emissions and improving fuel economy. Over the past 10 years almost all of the major　automotive

22、　companies have developed and released for sale their own hybrid electric　vehicles to the public. The popularity of hybrid electric vehicles has grown considerably since the turn of　the century. With enormous pressure to

23、 become more environmentally friendly and with　unpredictable gas prices, the sales of hybrid electri</p><p>　　2.1.1 Hybrid Configurations</p><p>　　For the past 100 years the objective of the hyb

24、rid has been to extend the range of electric　vehicles and to overcome the problem of long recharging times [35]. There are three　predominant hybrid electric vehicle configurations currently on the market today. These con

25、figurations are known as series hybrids, parallel hybrids and series/parallel hybrids.</p><p>　　Each configuration has its advantages and disadvantages which will be discussed in the following sections.</

26、p><p>　　Series Hybrids</p><p>　　In series hybrids the mechanical output from the internal combustion engine is used to　drive a generator which produces electrical power that can be stored in the ba

27、tteries or　used to power an electric motor and drive the wheels. There is no direct mechanical　connection between the engine and the driven wheels. Series hybrids tend to be used in　high power systems such as large truck

28、s or locomotives but can also be used for lower power passenger vehicles [18]. The mechanically generated electrica</p><p>　　There are many advantages made possible by the arrangement described above. It is

29、possible to run the ICE constantly at its most efficient operating point and share its electrical output between charging the battery and driving the electric motor. By operating the engine at its most efficient operatin

30、g point, emissions can be greatly reduced and the most electrical power can be generated per volume of fuel. This configuration is also easierto implement into a vehicle because it is less complex w</p><p>　

31、　Parallel Hybrids</p><p>　　In parallel hybrid configurations the mechanical energy output from the ICE is transmitted to a gearbox. In this gearbox the energy from the ICE can be mechanically combined with a

32、 second drive from an electric motor. The combined mechanical output is then used to drive the wheels [35]. In this configuration there is a direct connection between the engine and the driven wheels. As in series hybrid

33、s the controller compares the driver demand with the vehicle speed and output torque and determines </p><p>　　There are a number of advantages of a parallel hybrid over a series hybrid. The most important ad

34、vantage is that since only one conversion between electrical and mechanical power is made, efficiency will be much better than the series hybrid in which two conversions are required. Since the parallel hybrid has the ab

35、ility to combine both the engine and electric motor powers simultaneously, smaller electric motors can be used without sacrificing performance, while getting the fuel consumption and </p><p>　　Series/Paralle

36、l Hybrids</p><p>　　Combined hybrids have the features of both series and parallel configurations. They use a power split device to drive the wheels using dual sources of power (e.g. electric motor only, ICE

37、only or a combination of both). While the added benefits of both series hybrids and parallel hybrids are achieved for this configuration, control algorithms become very complex because of the large number of driving poss

38、ibilities available.</p><p>　　2.1.2 Degree of Hybridization</p><p>　　Since most HEV’s on the road today are either parallel or series/parallel, it is useful to define a variable called the ‘degr

39、ee of hybridization’ to quantify the electrical power potential of these vehicles.</p><p>　　The degree of hybridization ranges from (DOH = 0) for a conventional vehicle to (DOH = 1) for an all electric vehic

40、le [25]. As the degree of hybridization increases, a smaller ICE can be used and operated closer to its optimum efficiency for a greater proportion of the time, which will decrease fuel consumption and emissions. The ele

41、ctric motor power is denoted by Pem and the internal combustion engine power is denoted by Pice.</p><p>　　Micro Hybrid</p><p>　　Micro hybrids have the smallest degree of hybridization and usuall

42、y consist of an integrated starter generator (ISG) connected to the engine crankshaft. The ISG allows the engine to be shut off during braking and idling to conserve fuel and then spins the crankshaft up to speed before

43、fuel is injected during acceleration. The ISG also provides small amounts of assist to the ICE during acceleration and acts as a generator to charge the batteries during braking. Micro hybrids usually improve fuel </p

44、><p>　　Mild Hybrid</p><p>　　Mild hybrids have a similar architecture to the micro hybrid except that the ISG is uprated in power to typically greater than 20 kW. However, the energy storage system

45、is limited to less than 1 kWh [35]. Mild hybrids usually have a very short electric-only range capability but can provide a greater assist to the ICE during accelerations. The electrical components in a mild hybrid are m

46、ore complex than a micro hybrid and play a greater role in the vehicle operation. Fuel economy can be improved </p><p>　　Full Hybrid</p><p>　　Full hybrids do away with the ISG and replace it wit

47、h a separate electric motor and alternator/starter that perform the same function. The electric motor has the ability to propel the vehicle alone, particularly in city (stop and go) driving. The energy storage system is

48、upgraded to improve electric-only range capability and the engine is usually downsized to improve fuel economy and emissions. Full hybrids can achieve 40 to 45 percent fuel consumption reductions over non hybrids [53].&l

49、t;/p><p>　　Plug-in Hybrid</p><p>　　Plug-in hybrids are very similar to full hybrids except that they have a much larger ESS that can be connected to an outside electrical utility source for chargin

50、g. These vehicles use only the electric motor to propel the vehicle within the range of the batteries and then operate like full hybrids once the batteries have discharged to a predefined level.</p><p>　　2.1

51、.3 Fundamentals of Regenerative Braking</p><p>　　One of the most important features of HEV’s is their ability to recover significant amounts of braking energy. The electric motors can be controlled to operat

52、e as generators during braking to convert the kinetic energy of the vehicle into electrical energy that can be stored in the energy storage system and reused. However, the braking performance of a vehicle also greatly af

53、fects vehicle safety. In an emergency braking situation the vehicle must be stopped in the shortest possible distance and </p><p>　　Generally, the braking torque required is much larger than the torque that

54、an electric motor can produce [12]. Therefore, a mechanical friction braking system must coexist with the electrical regenerative braking. This coexistence demands proper design and control of both mechanical and electri

55、cal braking systems to ensure smooth, stable braking operations that will not adversely affect vehicle safety.</p><p>　　Energy Consumption in Braking</p><p>　　Braking a 1500 kg vehicle from 100

56、km/h to 0 km/h consumes about 0.16 kWh of energy based on Equation 2.2.</p><p>　　If 25 percent of this energy could be recovered through regenerative braking techniques, then Equation 2.2 can be used to esti

57、mate that this energy could be used to accelerate the vehicle from 0 km/h to about 50 km/h, neglecting aerodynamic drag, mechanical friction and rolling resistance during both braking and accelerating. This also assumes

58、that the generating and driving modes of the electric motor are 100% efficient. This suggests that the fuel economy of HEV’s can be greatly increased when</p><p>　　2.1.4 Methods of Regenerative Braking</p

59、><p>　　There are two basic regenerative braking methods used today. These methods are often referred to as parallel regenerative braking and series regenerative braking. Each of these braking strategies have ad

60、vantages and disadvantages that will be discussed in this section.</p><p>　　Parallel Regenerative Braking</p><p>　　During parallel regenerative braking, both the electric motor and mechanical br

61、aking system always work in parallel (together) to slow the vehicle down [48]. Since mechanical braking cannot be controlled independently of the brake pedal force it is converting some of the vehicle’s kinetic energy i

62、nto heat instead of electrical energy. This is not the most efficient regenerative braking method. However, parallel regenerative braking does have the advantages of being simple and cost effective. Fo</p><p&g

63、t;　　Series Regenerative Braking</p><p>　　During series regenerative braking the electric motor is solely used for braking. It is only when the motor or energy storage system can no longer accept more energy

64、that the mechanical brakes are used [48]. This method requires that the mechanical braking torque be controlled independently of the brake pedal force and has the advantage of being the most efficient by converting as mu

65、ch of the vehicle’s kinetic energy into electrical energy . The downfall of this method is that it brings many cos</p><p>　　2.1.5 Current Regenerative Braking Systems</p><p>　　The current regene

66、rative braking system in most HEV’s (e.g. Toyota Prius) is the more costly electro-hydraulic braking (EHB) system. This system uses a brake pedal simulator, which is separate from the hydraulic braking circuit, to establ

67、ish driver braking demand. The braking demand is then proportioned into a regenerative and mechanical braking demand. The mechanical braking demand is then sent to a system that contains a high pressure hydraulic pump, a

68、ccumulator and proportional control valves</p><p><b>　　譯 文</b></p><p>　　混合動力電動汽車機(jī)械和再生制動的整合</p><p><b>　　摘 要</b></p><p>　　為了減少對環(huán)境的污染和車輛的燃油消耗，混合

69、動力電動汽車已經(jīng)成為汽車工業(yè)的首選方法?；旌蟿恿﹄妱悠囃ㄟ^使用由電動馬達(dá)和內(nèi)燃發(fā)動機(jī)組成的混合動力系統(tǒng)來達(dá)到減少環(huán)境污染和燃油消耗的目的?；旌蟿恿ο到y(tǒng)消除了怠速，使發(fā)動機(jī)以一種更有效的方式運(yùn)行，增加了再生制動的使用。但是，混合動力的成本的增加阻礙了這些車輛的銷售。</p><p>　　在這里提出一個更具成本效益的電液制動系統(tǒng)的設(shè)計(jì)。該系統(tǒng)使用電控機(jī)械結(jié)合的控制方式控制制動助力器產(chǎn)生的推動力，并有足夠的時間反應(yīng)。

70、這個系統(tǒng)使駕駛員清楚地了解機(jī)械和再生制動力矩的混合，使再生制動力系統(tǒng)得到有效的控制。</p><p>　　一個系統(tǒng)化的設(shè)計(jì)過程是其次，重點(diǎn)在于展示概念設(shè)計(jì)方案的可行性和使用虛擬和實(shí)物模型的初步設(shè)計(jì)功用。虛擬和實(shí)物模型的結(jié)合使用成為驗(yàn)證和開發(fā)系統(tǒng)的強(qiáng)大工具，本文將介紹和討論在設(shè)計(jì)過程中模型所起到的作用。</p><p>　　因?yàn)樵谠O(shè)計(jì)過程中設(shè)計(jì)者可以獲得相關(guān)的經(jīng)驗(yàn)，提倡學(xué)生設(shè)計(jì)實(shí)物模型，以提

71、高學(xué)生的學(xué)習(xí)經(jīng)驗(yàn)。很明顯，這正是本文所要提出的。</p><p>　　1.1現(xiàn)代混合動力電動汽車</p><p>　　隨著油價的上漲和環(huán)境保護(hù)意識的提高，消費(fèi)者和政府迫使汽車行業(yè)開始生產(chǎn)省油和對環(huán)境污染小的汽車。一個有前景的方法就是現(xiàn)在實(shí)行的混合動力電動汽車。</p><p>　　混合動力汽車指的是有兩個或兩個以上動力來源的車輛。混合動力汽車動力的來源可能有很多的不

72、同，但是現(xiàn)在混合動力汽車最常見的布局是由內(nèi)燃發(fā)動機(jī)和電動馬達(dá)，能量儲存系統(tǒng)共同輸出動力，這樣的車輛就叫混合動力電動汽車。汽車可以同時使用發(fā)動機(jī)和電動馬達(dá)輸出的動力，從而可以提高汽車的使用性能和效率，進(jìn)而又可以提高燃油經(jīng)濟(jì)性，減少廢氣的排放，同時還能滿足消費(fèi)者對汽車性能的要求。1997年，豐田成普瑞斯為了第一款混合動力電動汽車，在日本進(jìn)行了批量生產(chǎn)。本田公司花費(fèi)了三年的時間進(jìn)行混合動力電動車的生產(chǎn)，然后進(jìn)軍北美市場。豐田普瑞斯在北美發(fā)行幾

73、個月后，本田Insight緊隨其后也在北美進(jìn)行發(fā)行。</p><p>　　混合動力電動車具有再生制動系統(tǒng)的獨(dú)特優(yōu)勢。在制動過程，通常用于動力輸出的電動馬達(dá)，可以起到發(fā)電機(jī)的功用，把汽車的動能轉(zhuǎn)化為蓄電池的電能，而不會轉(zhuǎn)化為熱能浪費(fèi)掉。轉(zhuǎn)換的電能可以儲存到蓄電池中，然后可以作為電動馬達(dá)驅(qū)動汽車使用的能量。</p><p>　　考慮到蓄電池能量密度時，動能轉(zhuǎn)換為電能這個過程就更加重要了。能量密

74、度是指單位體積或質(zhì)量下能量儲存系統(tǒng)所儲存的能量。為了說明這一點(diǎn)，我們可以做個對比，4.5公升的汽油通?？梢跃S持一輛汽車行駛50千米。而要把相同的能量儲存到蓄電池中，則需要一個質(zhì)量約為270千克的鉛酸蓄電池。這就說明了在汽車行駛過程中能夠有效地儲存再生制動系統(tǒng)產(chǎn)生的能量的重要性，從而可以保證在提高混合動力電能車性能的前提下，不至使能量儲存系統(tǒng)所占體積過大。</p><p>　　1.2再生制動系統(tǒng)研究范圍</p

75、><p>　　本文所提出的再生系統(tǒng)的研究范圍是研究再生制動系統(tǒng)和機(jī)械制動系統(tǒng)之間相互作用的關(guān)系，目的是設(shè)計(jì)開發(fā)出一個低成本的再生制動系統(tǒng)，從而可以應(yīng)用到未來經(jīng)濟(jì)型的混合動力電動汽車上。這個系統(tǒng)可以根據(jù)駕駛員的需要進(jìn)而控制再生制動系統(tǒng)和機(jī)械制動系統(tǒng)產(chǎn)生的制動力矩的結(jié)合，還應(yīng)該保證這個過程的平順性和安全性。再生制動力矩是通過使用的異步電動機(jī)的矢量控制算法進(jìn)行控制的。但是，獨(dú)立地控制制動踏板產(chǎn)生的機(jī)械制動力矩，同時又要保持

76、機(jī)械制動系在再生制動系統(tǒng)失效后起到備用作用，這是一個很大的難題。為了解決這個問題，需要研究一個通過減少制動主缸內(nèi)制動液壓來來控制機(jī)械制動系統(tǒng)產(chǎn)生的制動力矩的制動系統(tǒng)。</p><p>　　2.1混合電動汽車概述</p><p>　　混合動力電動車已經(jīng)成為了可以在短時間內(nèi)減少汽車污染排放和提高燃油經(jīng)濟(jì)型的解決方法之一。在過去的10年幾乎所有的主要汽車公司都已經(jīng)向公眾發(fā)行銷售自己的混合動力電動

77、汽車，混合動力電動汽車的普及和銷售在這個世紀(jì)有了很明顯的增長，隨著不可預(yù)測的汽油價格的增長和對環(huán)境保護(hù)的關(guān)注，混合動力電動汽車的銷售將在最近幾年內(nèi)急劇增長。</p><p>　　2.1.1混合動力裝置</p><p>　　在過去100年來混合動力的研究目標(biāo)是延長電動汽車的使用壽命，解決蓄電池的長期充電問題。在目前市場，現(xiàn)在主要有三種混合動力裝置，這些混合動力裝置為串聯(lián)混合動力，并聯(lián)混合動力

78、，串并聯(lián)混合動力。每一種動力裝置都有其優(yōu)點(diǎn)和缺點(diǎn)，這將在以后的章節(jié)進(jìn)行討論。</p><p><b>　　串聯(lián)混合動力</b></p><p>　　串聯(lián)混合動力汽車使用發(fā)動機(jī)輸出的動力來驅(qū)動發(fā)電機(jī)產(chǎn)生電能，這些電能可以儲存在蓄電池中，也可以用來驅(qū)動電動馬達(dá)來驅(qū)動汽車。在串聯(lián)混合動力汽車上，發(fā)動機(jī)和驅(qū)動輪之間沒有直接的機(jī)械連接，串聯(lián)混合動力往往在高功率系統(tǒng)中使用，如大型

79、貨車或火車，也可以應(yīng)用到低功率的客運(yùn)車輛上。發(fā)動機(jī)輸出的機(jī)械能和蓄電池輸出的電能可以通過電子控制器進(jìn)行控制接合，然后這個電子控制器通過比較駕駛員所需的動力和汽車車速，電動馬達(dá)輸出的轉(zhuǎn)矩，從而決定每個動力源驅(qū)動汽車行駛所要輸出的能量。在制動過程中，這個電子控制裝置可以使電能輸出模式轉(zhuǎn)換為再生模式，直接把再生制動系統(tǒng)產(chǎn)生的電能儲存在蓄電池內(nèi)。</p><p>　　按照這種布置方式進(jìn)行設(shè)計(jì)有很多的優(yōu)點(diǎn)。發(fā)動機(jī)可以保持高

80、效率的運(yùn)行，使發(fā)動機(jī)產(chǎn)生的電能在蓄電池和驅(qū)動馬達(dá)之間得到分配。發(fā)動機(jī)在其最高效率的工況下運(yùn)行，排放可以大大降低，燃燒每體積的燃料可以產(chǎn)生更多的電能。因?yàn)榇?lián)動力裝置結(jié)構(gòu)簡單且成本低，這種動力裝置很容在汽車上落實(shí)。</p><p><b>　　并聯(lián)混合動力</b></p><p>　　在并聯(lián)混合動力汽車中，發(fā)動機(jī)輸出的機(jī)械功傳到變速箱中。發(fā)動機(jī)輸出的機(jī)械功和電動馬達(dá)輸出

81、的功在變速箱內(nèi)進(jìn)行機(jī)械式的接合，混合的機(jī)械功用于驅(qū)動汽車行駛。在這種混合動力裝置結(jié)構(gòu)中，發(fā)動機(jī)和驅(qū)動輪之間有直接的機(jī)械連接。在串聯(lián)混合動力裝置中，電子控制器通過比較駕駛員所需的動力和汽車車速，電動馬達(dá)輸出的轉(zhuǎn)矩，從而決定每個動力源驅(qū)動汽車行駛所要輸出的能量，以滿足汽車行駛性能，獲得最佳的效率。正如串聯(lián)混合裝置一樣，并聯(lián)混合動力也以相似的方法控制再生制動。并聯(lián)混合動力裝置通常應(yīng)用到低功率的電動車中，這兩種驅(qū)動力可以同時使用，提供更高的行駛

82、性能。</p><p>　　與串聯(lián)混合動力系統(tǒng)相比，并聯(lián)混合動力系統(tǒng)有很多優(yōu)勢。其中最重要的一項(xiàng)優(yōu)勢是效率高，因?yàn)樵诓⒙?lián)混合動力中，電能和機(jī)械能只需轉(zhuǎn)換一次，而在串聯(lián)混合動力中，電能和機(jī)械能需要兩次轉(zhuǎn)換。由于并聯(lián)混合動力可以使發(fā)動機(jī)和電動馬大產(chǎn)生的動力同時結(jié)合起來，在不損失汽車行駛性能的前提下，可以使用體積小的電動馬達(dá)，同時也降低了油耗和排放。最后，并聯(lián)混合動力汽車在行駛過程中只需使發(fā)動機(jī)運(yùn)行，而不需要另一個發(fā)電

83、機(jī)為蓄電池充電。</p><p><b>　　串、并聯(lián)混合動力</b></p><p>　　串并聯(lián)混合動力裝置結(jié)合了串聯(lián)和并聯(lián)動力裝置的特點(diǎn)。這種混合方式汽車通過使用動力分配裝置來控制雙動力源（電動馬達(dá)輸出動力，發(fā)動機(jī)輸出動力或者兩者同時輸出）驅(qū)動汽車行駛。雖然這種裝置形式可以獲得串聯(lián)混合動力裝置和并聯(lián)混合動力裝置的優(yōu)點(diǎn)，因?yàn)榭紤]到汽車實(shí)際行駛可能性，這種裝置的控制算

84、法會變得非常復(fù)雜。</p><p><b>　　2.1.2混合度</b></p><p>　　現(xiàn)在道路上行駛的混合動力電動汽車大多是串聯(lián)混合動力，并聯(lián)混合動力，或者串并聯(lián)混合動力，因此定義一個‘混合度’變量來評價混合動力電動汽車的電能潛能是非常有意義的。</p><p>　　混合度變從傳統(tǒng)車輛（DOH=0）到所有電動車（DOH=1）之間變化，隨

85、著混合度的增加，在汽車上可以使用一個比較小的發(fā)動機(jī)，同時發(fā)動機(jī)可以在最接近最佳效率的工況下運(yùn)行很長的時間，這樣就可以減少燃油的消耗和廢氣的排放。電動馬達(dá)輸出的功用表示，發(fā)動機(jī)輸出的功用表示。</p><p><b>　　微混合動力</b></p><p>　　微混合指的是最小混合度，通常是由一個連接到發(fā)動機(jī)曲軸的綜合起動發(fā)電機(jī)組成。在加速和怠速過程中，綜合起動發(fā)電機(jī)使

86、發(fā)動機(jī)處于關(guān)閉狀態(tài)，從而節(jié)約燃油。加速時，在燃油噴入汽缸之前，綜合起動發(fā)電機(jī)使發(fā)動機(jī)的曲軸加速旋轉(zhuǎn)。在加速過程中，綜合起動發(fā)電機(jī)對發(fā)動機(jī)起動協(xié)助的作用，在制動過程中，綜合起動發(fā)電機(jī)還可以作為發(fā)電機(jī)向蓄電池充電。和非混合動力汽車相比，微混合動力汽車的燃油經(jīng)濟(jì)性可以提高10%左右。</p><p><b>　　輕混合動力</b></p><p>　　輕混合動力和微混合動力

87、結(jié)構(gòu)相似，有一點(diǎn)不同的是其綜合起動發(fā)電機(jī)是經(jīng)過改進(jìn)的，其輸出的動力可以超過20KW。但是，輕混合動力的能量儲存系統(tǒng)只能儲存1KWh左右的能量。輕混合動力汽車只有一個很短的純電動續(xù)航能力，但是可以在加速過程中給發(fā)動機(jī)提供很大的輔助作用。輕混合動力中的電子元件要比微混合動力中的電子元件復(fù)雜的多，且在汽車行駛過程中發(fā)揮著更大的作用。和非混合動力的汽車相比，輕混合動力汽車的燃油經(jīng)濟(jì)性可以提高20%-25%左右。</p><p

88、><b>　　全混合動力</b></p><p>　　在全混合動力汽車上不再使用綜合起動發(fā)電機(jī)，取代它的是一個獨(dú)立的電動馬達(dá)和交流發(fā)電機(jī)、起動機(jī)，這些裝置也可以起到綜合起動發(fā)電機(jī)的作用。電動馬達(dá)可以獨(dú)立驅(qū)動汽車行駛，尤其是在城市道路上（走走停停）的行駛。能量儲存系統(tǒng)也得到了改進(jìn)，這樣就提高了汽車純電動續(xù)航能力，減少了發(fā)動機(jī)的體積，從而提高燃油經(jīng)濟(jì)性和減少排放。與非混合動力汽車相比，全混

89、合動力汽車的燃油消耗量可以減少40%-50%。</p><p><b>　　插電式混合動力</b></p><p>　　插電式混合動力汽車在結(jié)構(gòu)上和全混合動力汽車相似，不同的是插電式混合動力汽車有一個比較大的能量儲存系統(tǒng)，可以通過與外部電源連接進(jìn)行充電。在蓄電池儲存能量范圍內(nèi)，可以通過電動馬達(dá)來驅(qū)動汽車行駛，但是當(dāng)蓄電池的能量降到一定水平后，其運(yùn)行形勢就和全混合動力一

90、樣了。</p><p>　　2.1.3再生制動原理</p><p>　　混合動力電動汽車最重要的特點(diǎn)是可以回收大量的制動能量。在制動過程中，電動馬達(dá)可以作為發(fā)電機(jī)來運(yùn)行操作，將制動過程中的動能轉(zhuǎn)換為電能儲存到蓄電池中，這些電能就可以被汽車重復(fù)使用。但是，車輛的制動性能就將影響到汽車的安全性。在緊急制動狀態(tài)下，汽車的制動距離要盡可能的短，還要保證制動時汽車有較好的方向穩(wěn)定性。汽車具有較好的方

91、向穩(wěn)定性，就需要控制車輪的制動力分配。</p><p>　　一般來說，制動時所需的制動力矩比電動馬達(dá)產(chǎn)生的制動力矩大得多。因此，機(jī)械制動系統(tǒng)需要和電子再生制動系統(tǒng)同時存在，這就需要適當(dāng)?shù)脑O(shè)計(jì)以保證制動時的操作穩(wěn)定性，不至于影響到汽車的安全性。</p><p><b>　　制動時能量消耗</b></p><p>　　由公式可得，一個質(zhì)量為1500

92、Kg的汽車以100km/h初速度制動到完全停止，需要消耗0.16kwh的動能。</p><p>　　如果這些能量的25%可以通過再生制動系統(tǒng)進(jìn)行回收，當(dāng)忽略制動和加速過程中的空氣阻力，機(jī)械摩擦和滾動阻力，假設(shè)電動馬達(dá)的工作效率100%，利用公式可以估算出，這些能量可以使汽車從0km/h加速到50km/h.這就表明，當(dāng)汽車行駛在城市道路上，汽車不停加速和制動，混合動力電動車的燃油經(jīng)濟(jì)性可以大大增加。需要注意的是，制

93、動能量的回收量受到馬達(dá)的型號和能量轉(zhuǎn)換率的限制。</p><p>　　2.1.4再生制動系統(tǒng)</p><p>　　目前，通常使用的有兩種再生制動方法。這些方法通常稱為串聯(lián)再生制動和并聯(lián)制動，每種制動策略都有其優(yōu)點(diǎn)和缺點(diǎn)，本文對此將進(jìn)行具體討論。</p><p><b>　　并聯(lián)再生制動</b></p><p>　　在并聯(lián)

94、再生制動系統(tǒng)中，電動馬達(dá)和機(jī)械制動系統(tǒng)同時工作，從而使汽車減速。因?yàn)闄C(jī)械制動系統(tǒng)不能獨(dú)立的控制制動力，使制動時的能量轉(zhuǎn)換為熱能而不是電能，因此這不是最有效地再生制動方法。但是并聯(lián)再生制動結(jié)構(gòu)簡單成本低，這就成為其一大優(yōu)勢。并聯(lián)再生制動的機(jī)械制動系統(tǒng)只需要稍加修改，而且電動馬達(dá)的控制算法也可以很容易在汽車上實(shí)現(xiàn)。這種制動方法還有一個額外的優(yōu)勢，當(dāng)再生制動系統(tǒng)發(fā)生故障時，機(jī)械制動系統(tǒng)可以起到備用的作用。</p><p&g

95、t;<b>　　串聯(lián)再生制動</b></p><p>　　在串聯(lián)再生制動中，電動馬達(dá)只有在制動時才起作用。只有當(dāng)電動馬達(dá)和能量儲存系統(tǒng)無法接受更多制動時所需的能量時，再生制動系統(tǒng)才起作用。串聯(lián)再生制動需要獨(dú)立的控制制動力矩，串聯(lián)再生制動可以高效率的把動能轉(zhuǎn)換為電能，這是其一項(xiàng)優(yōu)勢。但是它的不足之處在于，制動系統(tǒng)結(jié)構(gòu)復(fù)雜，成本高。這種制動方式需要制動踏板模擬器，制動系統(tǒng)也需要重新設(shè)計(jì)，這都會增

96、加其制造成本。因?yàn)橹苿酉到y(tǒng)需要裝有傳感器和信息處理器，這就會增加了結(jié)構(gòu)的復(fù)雜度。</p><p>　　2.1.5目前的再生制動系統(tǒng)</p><p>　　目前大多數(shù)混合動力電動汽車的再生制動系統(tǒng)都是比較昂貴的電液制動系統(tǒng)。再生制動系統(tǒng)使用制動踏板模擬器來建立駕駛者的制動需求，這個制動踏板模擬器與液壓制動電路獨(dú)立分開。這樣再將制動需求按照一定比例轉(zhuǎn)換為再生制動和機(jī)械制動需求，然后將機(jī)械制動需求