第10章 直流無刷電機

1、控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機IntroductionBLDC motors are one of the motor types rapidly gaining popularity. BLDC motors are used in industries such as Automotive, Aerospace, Consumer, Medical, Industrial Automation Equipment and Instrumentation. As the name implies, BLDC

2、 motors do not use brushes for commutation; instead, they are electronically commutated. Brushless DC electric motor (BLDC motors) also known as electronically commutated motors are synchronous motors that are powered by a DC electric source via an inverter, which produces an AC electric signal to d

3、rive the motor (AC, alternating current, does控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機not imply a sinusoidal waveform but rather a bi-directional current with no restriction on waveform); additional sensors and electronics control the inverter output amplitude and waveform and frequ

4、ency (i.e. rotor speed). A Brushless DC motor consists of three parts, a motor, the rotor position sensors and electronic switching circuit. principle block diagram of a brushless DC motor is shown in fig.10-1.DC power supplySwitching circuitMotorPosition SensorOutputFig.10-1 principle block diagram

5、 of brushless DC motors控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機翻譯v直流電機的電機類型之一的迅速普及。BLDC電機應(yīng)用在如汽車，航空航天，消費，醫(yī)療行業(yè)，工業(yè)自動化設(shè)備及儀表。顧名思義，BLDC電機不使用電刷換向；相反，它們是電子換向。無刷直流電機（BLDC電機）也被稱為電子換向電機同步電機，由直流電源通過逆變器驅(qū)動電機，產(chǎn)生交流電信號（交流，交流，并不意味著一個正弦波形而對波形沒有限制雙向電流）；附加傳感器和電子控制的逆變器輸出的幅值、波形和頻率（即轉(zhuǎn)速）?？刂齐姍C控制電機 (Control

6、Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機BLDC motors have many advantages over brushed DC motors and induction motors. A few of these are:直流電機在直流有刷電機和感應(yīng)電直流電機在直流有刷電機和感應(yīng)電機有許多優(yōu)點。這些都是一些：機有許多優(yōu)點。這些都是一些： Better speed versus torque characteristics更好的速

7、度和轉(zhuǎn)矩特性更好的速度和轉(zhuǎn)矩特性 High dynamic response高動態(tài)響應(yīng)高動態(tài)響應(yīng) High efficiency效率高效率高 Long operating life壽命長壽命長 Noiseless operation無聲運行無聲運行 Higher speed ranges高速范圍高速范圍控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機In addition, the ratio of torque delivered to the size of the motor is higher, making it u

8、seful in applications where space and weight are critical factors. We will discuss in detail the construction, working principle, characteristics and typical applications of BLDC motors.此此外，通過向電動機轉(zhuǎn)矩的大小比例較高，使得它在空間和重量是關(guān)鍵因素外，通過向電動機轉(zhuǎn)矩的大小比例較高，使得它在空間和重量是關(guān)鍵因素的應(yīng)用。我們將詳細討論的結(jié)構(gòu)，工作原理及典型應(yīng)用，直流電機的特點。的應(yīng)用。我們將詳細討論的結(jié)構(gòu)，

9、工作原理及典型應(yīng)用，直流電機的特點?？刂齐姍C控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機10.2 FUNDAMENTAL CONSTRUCTION AND OPERATING PRINCIPLE 基本結(jié)構(gòu)和工作原理基本結(jié)構(gòu)和工作原理BLDC motors are a type of synchronous motor. This means the magnetic field generated by the stator and the magnetic field generated by the rotor rotates

10、 at the same frequency. BLDC motors do not experience the “slip” that is normally seen in induction motors. BLDC motors come in single-phase, 2-phase and 3-phase configurations. Corresponding to its type, the stator has the same number of windings. Out of these, 3-phase motors are the most popular a

11、nd widely used.直流電機是一種同步電機。這意味著由轉(zhuǎn)子產(chǎn)生的磁場與定子所產(chǎn)直流電機是一種同步電機。這意味著由轉(zhuǎn)子產(chǎn)生的磁場與定子所產(chǎn)生的磁場，在相同的頻率旋轉(zhuǎn)。生的磁場，在相同的頻率旋轉(zhuǎn)。BLDC電機不經(jīng)歷電機不經(jīng)歷“滑滑”即是在感應(yīng)電動機通?？吹降?。直流電機是即是在感應(yīng)電動機通?？吹降?。直流電機是單相，兩相和三相配置。相應(yīng)的類型，定子繞組相同數(shù)量。從這些，三相異步電動機是最流行和廣單相，兩相和三相配置。相應(yīng)的類型，定子繞組相同數(shù)量。從這些，三相異步電動機是最流行和廣泛使用的。泛使用的?？刂齐姍C控制電機 (Control Electrical Machine)第十章第十章 無刷直

12、流電動機無刷直流電動機10.2.1 CONSTRUCTIONFigure 10-2 Construction控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機1) StatorThe stator of a BLDC motor consists of steel laminations with windings placed in the slots that are axially cut along the inner periphery. Traditionally, the stator resembles that

13、 of an induction motor; however, the windings are distributed in a different manner. Most BLDC motors have three stator windings connected in star fashion. Each of these windings are constructed with numerous coils interconnected to form a winding. One or more coils are placed in the slots and they

14、are控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機Figure 10-3 Statorinterconnected to make a winding. Each of these windings are distributed over the stator periphery to form an even numbers of poles. Figure 10-3一臺電機的定子由鋼疊片放置在沿內(nèi)周軸向切槽繞組。傳統(tǒng)上，定子類一臺電機的定子由鋼疊片放置在沿內(nèi)周軸向切槽繞組。傳統(tǒng)上，定子類似于一個感應(yīng)電動機；然而，繞組

15、分布在不同的方式。大多數(shù)的似于一個感應(yīng)電動機；然而，繞組分布在不同的方式。大多數(shù)的BLDC電機有三個定子繞組的星形連接方式。這些眾多的線圈繞組連接成一個電機有三個定子繞組的星形連接方式。這些眾多的線圈繞組連接成一個繞組構(gòu)造。一個或多個線圈被放置在插槽中，他們相互連接，使繞組。繞組構(gòu)造。一個或多個線圈被放置在插槽中，他們相互連接，使繞組。這些繞組分布在定子的外圍形成一個偶數(shù)極。圖這些繞組分布在定子的外圍形成一個偶數(shù)極。圖10-3控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機The armature winding connec

16、tions are shown in figure 10-4.(a)3-phase, star, 3-state; (b) 4-phase, star, 4-state(c) 3-phase, star, 6-state (d) 2-phase, orthogonal, 4-state控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機Figure10-4 Armature winding connection (e) 3-phase, delta, 6-state; (f) 4-phase, closed, 4-state控制電

17、機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機2) RotorThe following figure10-6 shows cross sections of different arrangements of magnets in a rotor.Figure 10-6控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機Unlike a brushed DC motor, the commutation of a BLDC motor is controlled e

18、lectronically. To rotate the BLDC motor, the stator windings should be energized in a sequence. It is important to know the rotor position in order to understand which winding will be energized following the energizing sequence. Rotor position is sensed using Hall effect sensors embedded into the st

19、ator. 不像有刷直流電機，一臺電機的換相控制電子。對不像有刷直流電機，一臺電機的換相控制電子。對BLDC電機旋轉(zhuǎn)，定子電機旋轉(zhuǎn)，定子繞組應(yīng)在順序通電。重要的是要知道為轉(zhuǎn)子位置，了解哪些繞組將通電后，通電順繞組應(yīng)在順序通電。重要的是要知道為轉(zhuǎn)子位置，了解哪些繞組將通電后，通電順序。轉(zhuǎn)子位置檢測采用霍爾傳感器嵌入定子。序。轉(zhuǎn)子位置檢測采用霍爾傳感器嵌入定子。3) Hall Sensors控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機Most BLDC motors have three Hall sensors embedd

20、ed into the stator on the non-driving end of the motor. Whenever the rotor magnetic poles pass near the Hall sensors, they give a high or low signal, indicating the N or S pole is passing near the sensors. Based on the combination of these three Hall sensor signals, the exact sequence of commutation

21、 can be determined.大多數(shù)的大多數(shù)的BLDC電機有三個霍爾傳感器電機有三個霍爾傳感器嵌入定子在電機的非驅(qū)動端。當(dāng)轉(zhuǎn)子的磁極通過附近的霍爾傳感器，他們給嵌入定子在電機的非驅(qū)動端。當(dāng)轉(zhuǎn)子的磁極通過附近的霍爾傳感器，他們給一個高或低信號，指示的一個高或低信號，指示的N或或S極附近時，傳感器?；谶@三個霍爾傳感器極附近時，傳感器?；谶@三個霍爾傳感器信號的組合，變換的精確序列可以確定。信號的組合，變換的精確序列可以確定?？刂齐姍C控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機(4) Electro-magnetic posi

22、tion sensor控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機10.2.2 Theory of Operation1) The operation principle of 3-phase, star, 3-state system is explained with figure 8.Figure 10-8 Operation principle控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機 electrical angle 0 2/3 4/3 2

23、conduction angles of state windingABCconducting transistorV1V2V3Table 10-1 Conduction sequence table of 3-phase, star, 3-state systemFigure 10-9 Phase voltages waveforms of BLDC控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機Fig.10-10 Torque waveform2) 3-phase, star, bridge connection控制電機控

24、制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機Fig.10-12 3-phase, star, bridge connectionV1 V6 (A+C-)V6V2 (B+C-)V2 V4 (B+A-)V4 V3 (C+A-)V3 V5 (C+B-)V5 V1(A+ B-)V1 V6 (A+C-)控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機Table 10-2 Conduction sequence table of 2-phase, star, 3-phase,6

25、-state systemElectrical angle 0 /3 2/3 4/3 5/3 2ConductionsequenceABCBCABV1Turn onV2Turn onV3Turn onV4Turn onV5Turn onTurn onV6Turn on控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機Figure10-13 Torque vector diagram控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機3) 3-phase, close

26、d, bridge connection.Figure10-14 3-phase, closed, bridge connectionV1 V6 A/(CB)V6V2 B /(CA)V2 V4 C /( BA)V4 V3 A /( BC)V3 V5 B / ( AC)V5 V1C / ( AB)V1 V6 A/(CB)控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機Table 10-3 Conduction sequence table of closed, star, 6-state systemElectrical ang

27、le 0 /3 2/3 4/3 5/3 2ConductionsequenceACBACBC BA BA CBCBAC AV1Turn onV2Turn onV3Turn onV4Turn onV5Turn onV6Turn onTurn on控制電機控制電機 (Control Electrical Machine)第十章第十章 無刷直流電動機無刷直流電動機10.3 COMPARING BLDC MOTORS TO OTHER MOTOR TYPESCompared to brushed DC motors and induction motors, BLDC motors have many

28、 advantages and few disadvantages. Brushless motors require less maintenance, so they have a longer life compared with brushed DC motors. BLDC motors produce more output power per frame size than brushed DC motors and induction motors. Because the rotor is made of permanent magnets, the rotor inertia is less, compared with other types of motors. This improves acceleration and deceleration characteristics, shortening operating cycles. 相比有刷直流電機和異步電機，直流電相比有刷直流電機和異步電機，直流電