三相异步电动机工作原理翻译

1、三相异步电动机的结构及工作原理一 结构 三相异步电动机的种类很多，但各类三相异步电动机的基本结构是相同的 它们都由定子和转子这两大基本部分组成，在定子和转子之间具有一定的气隙 此外，还有端盖、轴承、接线盒、吊环等其他附件，如图 1.1 所示。图 1.1 封闭式三相笼型异步电动机结构图1轴承；2前端盖；3转轴；4接线盒；5吊环；6定子铁心；7转子；8定子绕组；9机座；10后端盖；11风罩；12风扇1定子部分定子是用来产生旋转磁场的。三相电动机的定子一般由外壳、定子铁心、定 子绕组等部分组成。（1）外壳三相电动机外壳包括机座、端盖、轴承盖、接线盒及吊环等部件。 机座：铸铁或铸钢浇铸成型，它的作用是

2、保护和固定三相电动机的定子绕 组。中、小型三相电动机的机座还有两个端盖支承着转子，它是三相电动机机械 结构的重要组成部分。通常，机座的外表要求散热性能好，所以一般都铸有散热 片。端盖：用铸铁或铸钢浇铸成型，它的作用是把转子固定在定子内腔中心，使 转子能够在定子中均匀地旋转。轴承盖：也是铸铁或铸钢浇铸成型的，它的作用是固定转子，使转子不能轴 向移动，另外起存放润滑油和保护轴承的作用。接线盒：一般是用铸铁浇铸，其作用是保护和固定绕组的引出线端子。 吊环：一般是用铸钢制造，安装在机座的上端，用来起吊、搬抬三相电动机（2）定子铁心异步电动机定子铁心是电动机磁路的一部分，由0.35mm0.5mm厚表面涂

3、有绝缘漆的薄硅钢片叠压而成，如图 1.2 所示。由于硅钢片较薄而且片与片之间是 绝缘的，所以减少了由于交变磁通通过而引起的铁心涡流损耗。铁心内圆有均匀 分布的槽口，用来嵌放定子绕圈。（a） 定子铁心 （b） 定子冲片 图 1.2 定子铁心及冲片示意图（3）定子绕组定子绕组是三相电动机的电路部分，三相电动机有三相绕组，通入三相对 称电流时，就会产生旋转磁场。三相绕组由三个彼此独立的绕组组成，且每个绕 组又由若干线圈连接而成。每个绕组即为一相，每个绕组在空间相差 120电角 度。线圈由绝缘铜导线或绝缘铝导线绕制。中、小型三相电动机多采用圆漆包线， 大、中型三相电动机的定子线圈则用较大截面的绝缘扁铜

4、线或扁铝线绕制后，再 按一定规律嵌入定子铁心槽内。定子三相绕组的六个出线端都引至接线盒上，首 端分别标为U1, V1, W1，末端分别标为U2, V2, W2。这六个出线端在接线盒 里的排列如图1.3所示，可以接成星形或三角形。图1.3 定子绕组的联结(a)星形连接(b)三角形连接2转子部分( 1 )转子铁心是用 0.5mm 厚的硅钢片叠压而成，套在转轴上，作用和定子铁心相同，一 方面作为电动机磁路的一部分，一方面用来安放转子绕组。( 2)转子绕组 异步电动机的转子绕组分为绕线形与笼形两种，由此分为绕线转子异步电 动机与笼形异步电动机。 绕线形绕组 与定子绕组一样也是一个三相绕组，一般接成星形

5、，三相引出线分别接到 转轴上的三个与转轴绝缘的集电环上，通过电刷装置与外电路相连，这就有可能 在转子电路中串接电阻或电动势以改善电动机的运行性能，见图1.4。图 1.4 绕线形转子与外加变阻器的连接1集电环；2电刷；3变阻器 笼形绕组 在转子铁心的每一个槽中插入一根铜条，在铜条两端各用一个铜环（称为 端环）把导条连接起来，称为铜排转子，如图1.5 （a）所示。也可用铸铝的方 法，把转子导条和端环风扇叶片用铝液一次浇铸而成，称为铸铝转子，如图 1.5（b）所示。100kW以下的异步电动机一般采用铸铝转子。（a）铜排转子 （b）铸铝转子 图 1.5 笼形转子绕组3其他部分 其他部分包括端盖、风扇等

6、。端盖除了起防护作用外，在端盖上还装有轴承， 用以支撑转子轴。风扇则用来通风冷却电动机。三相异步电动机的定子与转子之 间的空气隙，一般仅为0.2mm1.5mm。气隙太大，电动机运行时的功率因数 降低；气隙太小，使装配困难，运行不可靠，高次谐波磁场增强，从而使附加损 耗增加以及使启动性能变差。二.三相异步电动机原理当向三相定子绕组中通过入对称的三相交流电时，就产生了一个以同步转速 n1 沿定子和转子内圆空间作顺时针方向旋转的旋转磁场。由于旋转磁场以 n1 转 速旋转，转子导体开始时是静止的，故转子导体将切割定子旋转磁场而产生感应 电动势（感应电动势的方向用右手定则判定）。由于导子导体两端被短路环

7、短接， 在感应电动势的作用下，转子导体中将产生与感应电动势方向基本一致的感生电 流。转子的载流导体在定子磁场中受到电磁力的作用（力的方向用左手定则判 定）。电磁力对转子轴产生电磁转矩，驱动转子沿着旋转磁场方向旋转。 通过上述分析可以总结出电动机工作原理为：当电动机的三相定子绕组（各相差 120 度电角度），通入三相对称交流电后，将产生一个旋转磁场，该旋转磁场切 割转子绕组，从而在转子绕组中产生感应电流（转子绕组是闭合通路），载流的 转子导体在定子旋转磁场作用下将产生电磁力，从而在电机转轴上形成电磁转 矩，驱动电动机旋转，并且电机旋转方向与旋转磁场方向相同The three-phase asyn

8、chronous motor structure and working principleThe structure of three-phase asynchronous motor:Types of three-phase asynchronous motor, but all kinds of three-phase asynchronous motor is the same basic structure, they are the stator and rotor of these two basic components, the stator and rotor has a

9、certain air gap between. In addition, end caps, bearings, cable boxes, rings and other accessories, As shown in Figure 1.1.Figure 1.1 Closed-end three-phase cage induction motor structure 1 - bearing; 2 - the front cover; 3 - axis; 4 - Junction Box; 5 - rings; 6 - stator core;7 - rotor; 8 - stator w

10、indings; 9 - base; 10 - after the end caps; 11 - wind shield; 12 - Fan1. Stator partStator is used to generate the rotating magnetic field. Stator three-phase motors generally shell, stator core, stator windings and other parts.shellThree-phase motor casing including base, end caps, bearing caps, ri

11、ngs, such as junction boxes and components.Machine Block: cast iron or steel casting molding, and its role is to protect and fixed three-phase motor stator windings. Small and medium-sized three-phase motor base and two end caps supporting the rotor, which is three-phase electrical machinery an impo

12、rtant part of the structure. Typically, the base looks good thermal performance requirements, so there are generally cast heat sink.Cover: The casting of cast iron or cast steel molding, which is fixed to the rotor center in the stator cavity, the rotor in the stator in the rotating evenly.Bearing C

13、aps: Cast iron or steel casting is formed, its role is a fixed rotor, the rotor can not move axially, and lubricants storage and protection from the role of bearing.Junction Box: Cast iron casting in general is that its role is to protect and fixed pinout terminals of the windings.Rings: steel manuf

14、acturing in general is installed in the upper base for lifting, moving, carrying three-phase motor.Stator Core Induction motor stator core is part of the motor circuit from 0.35mm 0.5mm thick coated with a thin insulating paint from silicon, as shown in Figure 1.2. And as a result of silicon thin fi

15、lm and between the insulation film, so reduced as a result of alternating magnetic flux through the core caused by eddy current loss. Core inner circle are uniformly distributed the slot to put the stator cruising inlay.(A) stator core (b) stator laminationFigure 1.2 Stator Core and red-chip diagram

16、The stator windingsThree-phase motor stator windings are part of the circuit, there are three-phase three-phase motor windings, symmetrical three-phase current access, it will have a rotating magnetic field. Three-phase winding consists of three separate components of the winding, and each has a num

17、ber of coil windings connected. Is a phase of each winding, each winding in the space angle difference between the 120 electrical. Coil of copper wire from the insulation or insulated aluminum wire around the system. Small and medium-sized three-phase motors use a round wire, large and medium-sized

18、three-phase motor stator windings are insulated with a larger cross-section aluminum flat wound copper wire or flat system, and then embedded in a certain law of stator core slots. Three-phase stator windings of the six round side are directed to the junction box on the first side, respectively, mar

19、ked U1, V1, W1, respectively, marked as the end of U2, V2, W2. The six round side of the box with the wiring as shown in Figure 1.3, you can access into a star or triangle.Figure 1.3 links the stator windings(A) star connection (b) triangle connectingRotor part (1) Rotor CoreWith 0.5mm thick steel f

20、rom, set in the shaft, the role and the same stator core, on the one hand, as part of the motor magnetic circuit, on the one hand to place the rotor windings.(2) rotor windingsThe rotor winding induction motor winding is divided into two kinds of cage-shaped and which is divided into winding rotor a

21、synchronous motor with cage induction motor. shaped winding windingLike with the stator windings is also a three-phase winding, the general access into astrocytes, respectively, received a three-phase pinout on the three axes and axes of the collector ring insulation, and through the brush device co

22、nnected with the external circuit, which may circuit in the rotor resistance or electromotive force in series in order to improve the operation of motor performance, see Figure 1.4.Figure 1.4 Rotor winding-shaped connection with the plus rheostat 1 - collecting ring; 2 - Brush; 3 - Varistors cage wi

23、ndingRotor core in each slot a copper insert in the ends of the copper with a 铜环(known as side Wan) to conn ect the lead article, called copper rotor, Figure 1.5 (a) as shown in . Aluminum methods can also be used to guide the rotor end ring and fan blades made of aluminum casting a liquid, known as

24、 cast aluminum rotor, Figure 1.5 (b) below. Following the induction motor 100kW generally cast aluminum rotor.(a) copper rotor (b) cast aluminum rotorFigure 1.5 Rotor cageOther parts ofOther parts including the cover, fans, etc. In addition to the role of end caps to protect, in the end caps is also

25、 fitted with bearings to support the rotor shaft. Cooling fan motor is used for ventilation. Three-phase asynchronous motor stator and rotor of the air gap between the general is only 0.2mm 1.5mm. Air gap too large, the motor run-time to reduce the power factor; air-gap is too small to make the asse

26、mbly difficult, does not run a reliable, high-harmonic magnetic field increased, thus increasing wear and tear as well as additional start-up performance to deteriorateII. The principle of three-phase asynchronous motor : When the three-phase stator windings through the three-phase alternating curre

27、nt into symmetric, they have had a n1 synchronous speed along the stator and rotor space for inner circle clockwise rotation of the rotating magnetic field. As the rotation speed of rotating magnetic field to n1, the beginning of the rotor conductors is static, it will be cutting the rotor conductor

28、s in the stator rotating magnetic field induction electromotive force generated(electromotive force induced by the direction of right-hand rule to determine). Since the derivation conductor ring at both ends by a short circuit shorted, the role of EMF in the sensor, the rotor conductors and inductive electromotive force will produce basically the same as the direction of the induced current. Rotor stator cu