第10章 直流无刷电机

1、控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机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控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机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控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机翻译v直流电机的电机类型之一的迅速普及。BLDC电机应用在如汽车，航空航天，消费，医疗行业，工业自动化设备及仪表。顾名思义，BLDC电机不使用电刷换向；相反，它们是电子换向。无刷直流电机（BLDC电机）也被称为电子换向电机同步电机，由直流电源通过逆变器驱动电机，产生交流电信号（交流，交流，并不意味着一个正弦波形而对波形没有限制双向电流）；附加传感器和电子控制的逆变器输出的幅值、波形和频率（即转速）。控制电机控制电机 (Control

6、Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机BLDC motors have many advantages over brushed DC motors and induction motors. A few of these are:直流电机在直流有刷电机和感应电直流电机在直流有刷电机和感应电机有许多优点。这些都是一些：机有许多优点。这些都是一些： Better speed versus torque characteristics更好的速

7、度和转矩特性更好的速度和转矩特性 High dynamic response高动态响应高动态响应 High efficiency效率高效率高 Long operating life寿命长寿命长 Noiseless operation无声运行无声运行 Higher speed ranges高速范围高速范围控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机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，通过向电动机转矩的大小比例较高，使得它在空间和重量是关键因素外，通过向电动机转矩的大小比例较高，使得它在空间和重量是关键因素的应用。我们将详细讨论的结构，工作原理及典型应用，直流电机的特点。的应用。我们将详细讨论的结构，

9、工作原理及典型应用，直流电机的特点。控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机10.2 FUNDAMENTAL CONSTRUCTION AND OPERATING PRINCIPLE 基本结构和工作原理基本结构和工作原理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.直流电机是一种同步电机。这意味着由转子产生的磁场与定子所产直流电机是一种同步电机。这意味着由转子产生的磁场与定子所产生的磁场，在相同的频率旋转。生的磁场，在相同的频率旋转。BLDC电机不经历电机不经历“滑滑”即是在感应电动机通常看到的。直流电机是即是在感应电动机通常看到的。直流电机是单相，两相和三相配置。相应的类型，定子绕组相同数量。从这些，三相异步电动机是最流行和广单相，两相和三相配置。相应的类型，定子绕组相同数量。从这些，三相异步电动机是最流行和广泛使用的。泛使用的。控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直

12、流电动机无刷直流电动机10.2.1 CONSTRUCTIONFigure 10-2 Construction控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机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控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机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 10-3一台电机的定子由钢叠片放置在沿内周轴向切槽绕组。传统上，定子类一台电机的定子由钢叠片放置在沿内周轴向切槽绕组。传统上，定子类似于一个感应电动机；然而，绕组

15、分布在不同的方式。大多数的似于一个感应电动机；然而，绕组分布在不同的方式。大多数的BLDC电机有三个定子绕组的星形连接方式。这些众多的线圈绕组连接成一个电机有三个定子绕组的星形连接方式。这些众多的线圈绕组连接成一个绕组构造。一个或多个线圈被放置在插槽中，他们相互连接，使绕组。绕组构造。一个或多个线圈被放置在插槽中，他们相互连接，使绕组。这些绕组分布在定子的外围形成一个偶数极。图这些绕组分布在定子的外围形成一个偶数极。图10-3控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机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控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机Figure10-4 Armature winding connection (e) 3-phase, delta, 6-state; (f) 4-phase, closed, 4-state控制电

17、机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机2) RotorThe following figure10-6 shows cross sections of different arrangements of magnets in a rotor.Figure 10-6控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机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. 不像有刷直流电机，一台电机的换相控制电子。对不像有刷直流电机，一台电机的换相控制电子。对BLDC电机旋转，定子电机旋转，定子绕组应在顺序通电。重要的是要知道为转子位置，了解哪些绕组将通电后，通电顺绕组应在顺序通电。重要的是要知道为转子位置，了解哪些绕组将通电后，通电顺序。转子位置检测采用霍尔传感器嵌入定子。序。转子位置检测采用霍尔传感器嵌入定子。3) Hall Sensors控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机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.大多数的大多数的BLDC电机有三个霍尔传感器电机有三个霍尔传感器嵌入定子在电机的非驱动端。当转子的磁极通过附近的霍尔传感器，他们给嵌入定子在电机的非驱动端。当转子的磁极通过附近的霍尔传感器，他们给一个高或低信号，指示的一个高或低信号，指示的N或或S极附近时，传感器。基于这三个霍尔传感器极附近时，传感器。基于这三个霍尔传感器信号的组合，变换的精确序列可以确定。信号的组合，变换的精确序列可以确定。控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机(4) Electro-magnetic posi

22、tion sensor控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机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控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机 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控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机Fig.10-10 Torque waveform2) 3-phase, star, bridge connection控制电机控

24、制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机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-)控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机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控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机Figure10-13 Torque vector diagram控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机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)控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机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控制电机控制电机 (Control Electrical Machine)第十章第十章 无刷直流电动机无刷直流电动机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. 相比有刷直流电机和异步电机，直流电相比有刷直流电机和异步电机，直流电