1、本章学习内容本章学习内容Chapter 3 Traction Motors and Controllers 牵引电动机与控制器牵引电动机与控制器本章学习目标本章学习目标本章难点重点本章难点重点3.1 Types of Traction Motors 牵引电动机的类型牵引电动机的类型3.2 Construction and Principle 结构与原理结构与原理3.3 Motor Control System(controllers)电动机控制电动机控制系统系统3.4 Service and Testing 维护与测试维护与测试 1.1.掌握重要的牵引电动机和控制器的基本英文术语;掌握重要的牵
2、引电动机和控制器的基本英文术语;2.2.掌握牵引电动机和控制器的结构、原理和维护;掌握牵引电动机和控制器的结构、原理和维护;3.3.了解牵引电动机和控制器维护了解牵引电动机和控制器维护1.1.重点:电机结构及控制原理,英文专业术语;重点:电机结构及控制原理,英文专业术语;2.2.难点:基本术语难点:基本术语New Words and Phrases3.1 Types of Traction Motors 牵引电动机的类型牵引电动机的类型approach prtvt.&vi.接近接近armature:mt(r)n.电枢电枢;转子转子asynchronouseskrnsadj.异步的异步的comm
3、utation?kmjutenn.换向换向excitation?eksatenn.励磁励磁interior-mountedadj.内部安装的,内装式内部安装的,内装式magnetmgntn.磁铁,磁体磁铁,磁体3.1 Types of Traction Motors 牵引电动机的类型牵引电动机的类型rare-earthrer:n.稀土稀土rotorrt(r)n.转子转子secureskj(r)adj.安全的安全的;牢固的牢固的slip-ringn.滑环滑环surface-mountedadj.安装在表面上的安装在表面上的synchronousskrnsadj.同步的同步的3.1 Types o
4、f Traction Motors 牵引电动机的类型牵引电动机的类型armature winding电枢绕组电枢绕组asynchronous AC motor异步交流电动机异步交流电动机excitation current励磁电流励磁电流field winding磁场绕组磁场绕组motor vehicle汽车,机动车汽车,机动车ohmic loss电阻损耗电阻损耗3.1 Types of Traction Motors 牵引电动机的类型牵引电动机的类型passenger vehicle乘用车,载客车辆乘用车,载客车辆permanent magnet永久磁铁永久磁铁power plant发电厂,
5、动力装置发电厂,动力装置series-wound DC motor串励式直流发电机串励式直流发电机synchronous AC motor同步交流电动机同步交流电动机3.1 Types of Traction Motors 牵引电动机的类型牵引电动机的类型Text Two types of electric motor are commonly used in electric vehicles:the direct current(DC)motor and the alternating current(AC)motor.3.1 Types of Traction Motors 3.1 Ty
6、pes of Traction Motors 牵引电动机的类型牵引电动机的类型3.1 Types of Traction Motors 牵引电动机的类型牵引电动机的类型DC motors In most electric industrial trucks,the series-wound DC motors,as shown in Figure 3.1a,are used.In these motors,the field and armature windings are in series.Representative torque-power-speed characteristics
7、 of this type of motor are shown in Figure 3.1b.While the efficiency of the series-wound DC motor is relatively low,it is still being used because of its simple design and low cost.Separately excited(shunt)DC motors are also used in some electric vehicles.3.1 Types of Traction Motors 牵引电动机的类型牵引电动机的类
8、型Fig.3.1 The series-wound DC motor and its torque-power-speed characteristics AC motors3.1 Types of Traction Motors 牵引电动机的类型牵引电动机的类型AC motors Synchronous or asynchronous AC motors are now the norm as traction motors for passenger vehicles.To convert DC supplied by the battery to AC,an inverter is re
9、quired.The maintenance cost of these AC motors is lower than that of DC motors,as they do not require brush/commutation or slip-ring system.The synchronous motor with high density,rare-earth permanent magnets mounted on the rotor is widely used in electric or hybrid passenger vehicles.The permanent
10、magnets may be mounted on the surface of the rotor,as shown in Fig.3.2a,or mounted in the interior of the rotor.Interior-mounted permanent magnets are more secure than surface-mounted permanent magnets for high-speed operations.3.1 Types of Traction Motors 牵引电动机的类型牵引电动机的类型Fig.3.2 The permanent magne
11、t synchronous AC motor and its torque-power-speed characteristics.3.1 Types of Traction Motors 牵引电动机的类型牵引电动机的类型 The permanent magnet synchronous AC motor generally has higher efficiency than the conventional synchronous motor,due to the elimination of the excitation current drawn from the energy sou
12、rce and to the elimination of the ohmic loss in the rotor winding(field winding).While rare-earth magnets make the motor more expensive,their use allows compact design with high torques.Representative torque-power-speed characteristics of this type of motor are shown in Fig.3.2b.Characteristics of t
13、he permanent magnet synchronous AC motor approach those of the ideal power plant for application to motor vehicles.This also allows the use of a single-stage reduction gear in the drive train.3.2 Construction and Principle 结构与原理结构与原理New Words and Phrasesactivation?ktvenn.活化,激活活化,激活brushbrn.刷子,电刷刷子,电
14、刷brushlessbrlsadj.无刷的无刷的chasetesvi.追逐,追赶追逐,追赶commutator kmjutet(r)n.换向器换向器compel kmpelvt.强迫,迫使强迫,迫使3.2 Construction and Principle 结构与原理结构与原理deactivationdi:ktvenn.失活,钝化失活,钝化electromagnetlektrmgntn.电磁体,电磁铁电磁体,电磁铁energize endazvt.给给加电压,通电加电压,通电illustration?lstrenn.说明,插图说明,插图loop lu:pn.圈,环,回路圈,环,回路magne
15、tic mgnetkadj.有磁性的,磁性的有磁性的,磁性的3.2 Construction and Principle 结构与原理结构与原理perpendicular?p:pndkjl(r)adj.垂直的,成直角的垂直的,成直角的spring-loadedadj.受弹簧力作用的受弹簧力作用的squirrel-cageskwrlked鼠笼式鼠笼式statorstet n.定子定子submultiplesbmltpln.约数,因数约数,因数wrap rpvt.包包;缠绕缠绕3.2 Construction and Principle 结构与原理结构与原理AC induction motor(AC
16、IM)交流感应式电动机交流感应式电动机be perpendicular to垂直于垂直于commutator segment换向器片换向器片current-carrying conductor载流导体载流导体electromagnetic induction电磁感应电磁感应electronic switch电子开关电子开关3.2 Construction and Principle 结构与原理结构与原理field coil励磁线圈,磁场线圈励磁线圈,磁场线圈Hall-effect sensor霍尔效应传感器霍尔效应传感器interior permanent magnet(IPM)内部永磁内部永
17、磁magnetic field磁场磁场make electrical contact with与与电接触电接触permanent magnet brushless DC motor永磁无刷直流电动机永磁无刷直流电动机3.2 Construction and Principle 结构与原理结构与原理pole shoes极靴极靴squirrel-cage rotor鼠笼式转子鼠笼式转子starting torque启动力矩启动力矩surface permanent magnet(SPM)表面永磁表面永磁wound rotor绕线式转子绕线式转子3.2 Construction and Princi
18、ple 结构与原理结构与原理3.2.1 Electric Motor Operation3.2.1 Electric Motor OperationBasic principle A current-carrying conductor is placed in a magnetic field,then,it is compelled to move from strong field to weak field.The direction of movement is perpendicular to both the conductor and the magnetic field,se
19、e Figure 3.3a.When the conductor formed a loop is placed in a magnetic field,it is compelled to rotate,see Figure 3.3b.3.2 Construction and Principle 结构与原理结构与原理Figure 3.3 A current-carrying conductor placed in a magnetic field3.2 Construction and Principle 结构与原理结构与原理ConstructionA simple electric mot
20、or is shown in Figure 3.4.The conductive loop that rotates in an electric motor is called an armature.The armature is connected to a ring that is similar to alternator rotor slip rings.However,the slip ring in this simple motor is split into two.This two-piece slip ring causes current to flow throug
21、h one-half of the split ring,through the loop of wire,to the other half of the split ring.This split slip ring in a motor is referred to as a commutator.Each piece of the commutator is called a commutator segment.Spring-loaded brushes make electrical contact with the commutator segments.The brushes
22、and commutator segments permit the armature to rotate yet still make electrical contact.3.2 Construction and Principle 结构与原理结构与原理Figure 3.4 A simple motor3.2 Construction and Principle 结构与原理结构与原理The two magnets shown surrounding the armature in Figure 3.4 are electromagnets called pole shoes.Loops o
23、f copper conductor called the field coils or field windings are wrapped around the pole shoes.The field coil is wrapped in such a direction to cause the half of the pole shoe facing the armature to become a north pole magnet.The pole shoe on the left side of this illustration has the field coils wra
24、pped such that the side of the pole shoe facing the armature becomes a south pole magnet.3.2 Construction and Principle 结构与原理结构与原理 Current flows in accordance with such a path:Positive battery terminal right side field coil left side field coil left side brush split ring commutator armature loop oth
25、er side of the split ring commutator right side brush battery-negative terminal.The armature,commutator and shaft to which the armature and commutator are installed and rotated together are called rotor.The field coils,pole shoes and brushes are called stator.3.2 Construction and Principle 结构与原理结构与原
26、理3.2.2 AC asynchronous motor3.2.2 AC asynchronous motorThe motor uses electromagnetic induction from the stator to induce a current and therefore creates a magnetic field in the rotor without the need for brushes.An AC asynchronous motor is also known as an AC induction motor(ACIM),because it allows
27、 a certain amount of slip between the rotor and the changing magnetic field in the stator.The term asynchronous means that the speed of the motor is not necessarily related to the frequency of the current flowing through the stator windings.3.2 Construction and Principle 结构与原理结构与原理ACIMs include squi
28、rrel-cage and wound-rotor induction designs.A squirrel-cage rotor,as shown in Figure 3.5,is composed of parallel thick copper or aluminum conductors connected to a ring of the same material at the ends.As the stator magnetic field rotates,the stator field interacts with the magnetic field of the rot
29、or,causing the rotor to turn at nearly the speed of the rotating stator magnetic field.An alternate design is called the wound rotor,as shown in Figure 3.6.In this case,the rotor has the same number of poles as the stator,and the windings are made of wire.When the stator magnetic field rotates and t
30、he rotor windings are shorted,the stator magnetic field motion induces a field in the wound rotor,causing the rotor to turn at nearly the speed of the rotating stator magnetic field.3.2 Construction and Principle 结构与原理结构与原理Figure 3.5 A squirrel-cage rotorFigure 3.6 A typical motor design with a woun
31、d rotor3.2 Construction and Principle 结构与原理结构与原理3.2.3 AC synchronous motor3.2.3 AC synchronous motor The AC synchronous motor rotates exactly at the supply frequency or a submultiple of the supply frequency.The speed is controlled by varying the frequency of the AC supply and the number of poles in
32、the stator winding.An electronic switching circuit produces commutating currents in the stator windings based on the position of the magnetic poles on the rotor.The rotor of the motor rotates at the same speed as the stator commutation.The speed of the motor is controlled by the frequency of the AC
33、current being used.3.2 Construction and Principle 结构与原理结构与原理 The brushless permanent magnet synchronous motors produce high starting torque and are typically over 90%efficient.There are two types of rotor designs:The permanent magnets are mounted on the outside surface of the rotor,as shown in Figur
34、e 3.2a.These are called surface permanent magnets(SPMs).The permanent magnets are housed inside the outer shell of the rotor and are called interior permanent magnets(IPMs),The Honda,Ford and Toyota hybrids use an IPM-type rotor assembly.3.2 Construction and Principle 结构与原理结构与原理 In both types of mot
35、ors,the stator coils are stationary and the permanent magnet assembly rotates.Alternating current(AC)is fed to the various phases in the stator in order to get the permanent magnets in the rotor to chase the changing magnetic field,as shown in Figure 3.7.The current is fed into one of the three stat
36、or phases and flows out of a second phase.This current flows through the phases,acts as a position sensor,and helps the controller to determine when to energize which phase of the stator.3.2 Construction and Principle 结构与原理结构与原理Figure 3.7 The rotor is forced to rotate by changing the polarityand the
37、 frequency of the coils surrounding the rotor3.2 Construction and Principle 结构与原理结构与原理3.2.4 Permanent magnet brushless DC motor3.2.4 Permanent magnet brushless DC motorIn permanent magnet brushless DC motors,the activation and deactivation of the individual windings is carried out with the help of c
38、ontrol electronics(electronic switch),see Figure 3.8.The control electronics receive information on the position of the rotor from the rotor position sensor,e.g.a Hall-effect sensor,and activate or deactivate the corresponding windings in the stator,to produce rotating magnetic fields.The speed of t
39、he motor depends on the commutation frequency of the commutation device.Electronically commutated DC motors usually have three or more windings.3.2 Construction and Principle 结构与原理结构与原理Figure 3.8 permanent magnet brushless DC motor3.2 Construction and Principle 结构与原理结构与原理 Advantages of permanent mag
40、net brushless DC motors compared with mechanically commutated motors:Possibility of higher rotational speeds.Quiet operation,good electromagnetic compatibility and reduced maintenance.Diagnostic capability of the control electronics and smooth mechanical running.Compact construction and low weight.C
41、onstruction of permanent magnet brushless DC motor is shown in Figure 3.9.3.2 Construction and Principle 结构与原理结构与原理Figure 3.9 Construction of permanent magnet brushless DC motor小小 结结3.1 Types of Traction Motors 牵引电动机的类型牵引电动机的类型Two types of electric motor are commonly used in electric vehicles:direct
42、 current(DC)motor alternating current(AC)motor 3.2 Construction and Principle 结构与原理结构与原理 Permanent magnet brushless DC motor AC asynchronous motor AC synchronous motor作业作业oWhat are the two types of motor?电动机分为哪两种类电动机分为哪两种类型?型?oWhat are the types of motors commonly used in electric vehicles?电动汽车常用的电动机分有哪几种类型?电动汽车常用的电动机分有哪几种类型?oWhat are the main components of the basic structure of electric motor used in electric vehicles?电动汽车用电动机的基本结构主要由哪些部件构成?电动汽车用电动机的基本结构主要由哪些部件构成?o记忆电动汽车电动机的专业英文术语记忆电动汽车电动机的专业英文术语
侵权处理QQ:3464097650--上传资料QQ:3464097650
【声明】本站为“文档C2C交易模式”,即用户上传的文档直接卖给(下载)用户,本站只是网络空间服务平台,本站所有原创文档下载所得归上传人所有,如您发现上传作品侵犯了您的版权,请立刻联系我们并提供证据,我们将在3个工作日内予以改正。