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Three-phase alternator working principle | generator series courseware The practical application is mainly a three-phase alternator. The inner circumference of the stator core is evenly distributed with six slots, and three identical coils spaced 120 degrees apart are embedded, which are respectively called A-phase coil, B-phase coil, and C-phase coil. The three-phase alternator in the picture adopts the star connection method, the outgoing line from common point of the three coils is a neutral line, and the outgoing line of each coil is a phase line. Figure 1--Three-phase alternator stator At present, power plants mainly use steam turbines or gas turbines to drive generators with high rotation speed. The generator rotor has 2 magnetic poles. The structure of the generator rotor has a salient pole type (figure 2 left) and a hidden pole type (figure 2 right). Most

  Single Phase Permanent Alternator model There is an introduction about working principle of alternator in the alternator principle courseware, but the simple principle model has low power generation efficiency, the rotating coil is hollow, the space is air, and the magnetic resistance is extremely large, resulting in low spatial flux density. As we all know, the induced electromotive force of a moving wire depends on the magnetic flux scanned per unit time. When the wire length and the moving speed are constant, the induced electromotive force is proportional to the magnetic flux density of the scanning space. The method of increasing the magnetic field potential is very limited, a simple method is to turn the space into a material with high magnetic permeability, which is to build a rotor core with high magnetic permeability and wind the coil around the rotor core. Air gap is so narrow left between poles that the magnetic resistance of the entire magnetic circuit is greatly reduced,

多磁极三相发电机原理模型 Principle of Multipolar Three-phase Generator 个磁极，图1是一个6极三相交 图1--6极发电机模型的定子铁芯与转子铁芯 转子有3对磁极，由于每个磁极都是从转子上明显凸起，称之为 凸极式转子 。磁极安装在转子磁轭上。 图2--凸极式转子铁芯 每个凸起的磁极上都绕有励磁线圈，见图3。 图3—绕有线圈的凸极转子 接上励磁电源通过滑环向励磁线圈供电，形成南北相间的6个磁极，凸极的磁力线见图4。 图4--凸极转子的磁场 凸极式转子也可采用永磁体制作转子磁极，在 直驱式风力发电机 与小型永磁发电机中有广泛的应用，图5是有3对永磁体磁极的转子。 图5—永磁体凸极转子的磁场 转子有3对磁极，旋转一周磁场将循环3个周期，旋转120度磁场变化1个周期。定子铁芯的槽数是18个或36个等数，我们这个模型的内园周有18个嵌线槽，见图6。 图6--定子铁芯 在120度机械角度里有6个槽，均匀分布A相、B相、C相3个线圈；另外两个120度里同样各自分布3个线圈。3个A相线圈串联起来即为整机的A相绕组，3个B相线圈串联起来即为整机的B相绕组，3个C相线圈串联起来即为整机的C相绕组，3个绕组按 星形接法 将三个绕组尾端连在一起引出即中性线，为看清线圈的分布与连接，图7中定子为半透明。 图7--定子线圈的分布与连接 3个绕组的另一端是A相输出端、B相输出端、C相输出端。 图8--定子铁心与3相绕组 把凸极转子插在定子中，与定子有很小间隙，可自由旋转。图9就是多磁极发电机的原理模型。 图9--多磁极发电机原理模型 当转子匀速旋转时A、B、C相线圈顺序切割磁力线，都会感生交流电动势，其幅度与频率相同。由于三个线圈均匀分布，它们感应电势的相位也相差120度电角度（每周期为360度电角度）。 当转子旋转一周将感生出3个周期的三相交流电动势。当转子转速为每分钟1000转时，所感生交流电动势的频率为50赫兹。 本模型仅是个原理模型，定子线圈的分布与连接仅表示基本规律，实际发电机上定子的槽数要多得多， 绕组 分布也复杂得多。 下面是多磁极发电机的原理模型的3D动画,动画中有每根相线的输出电势波形。  

  Three-phase AC motor winding The basics of AC motor windings are introduced in the "AC Motor Winding" courseware, and the windings of single-phase motors are introduced. The windings of three-phase AC motors are introduced in this courseware. Three-phase AC motor winding basic structure It is well known that both electromotive force induced in the three-phase AC motor produces and rotating magnetic field generated on the three-phase AC generator are from an important part of the motor or generator, that is, the windings. The basic requirement for three-phase AC motor windings is: The potential  waveform generated by the three-phase AC motor and the magnetic field of the three-phase AC motor must be close to a sine wave and achieve the required amplitude. The potential or magnetic field generated by the three-phase windings must be symmetrical, and the resistance and reactance of each winding should be balanced. The copper loss of the winding is small, and the same to the am

  AC Motor Winding For the generator, the winding is the component that generates the electromotive force, for the motor, the winding is the component that generates the mechanical force. Obviously the winding is the main component of the energy conversion and the most important component, the core of both stator and rotor is just used to reduce magnetic force and increase the magnetic path of magnetic flux. AC motors mainly have single-phase motors and multi-phase motors, and three-phase motor is mainly multi-phase motor. The principle of three-phase AC generator is introduced in this column "Three-phase AC generator principle model”, and the characteristics of three-phase alternating current are introduced in the motor column, "Rotating magnetic field generated by three-phase AC motor”, the model there uses a single-turn wire to represent winding, there is a little difference from the actual application In this course, we introduce the basic structure of the actual AC motor