A-B罗克韦尔 1756-L542 ab处理器模块

A-B罗克韦尔 1756-L542 ab处理器模块

交流电动机由定子和转子组成，交流电动机分为同步交流电动机和感应电动机两种。两种电机均为定子侧绕组通入交流电产生旋转磁场，但同步交流电动机的转子绕组通常需要激磁机需要供给直流电（激磁电流）；而感应电动机则转子绕组则无需通入电流。

三相交流电动机的定子绕组基本上是三个相互隔开120度的线圈，作三角形或星形联结。通入三相电流时，在每个线圈中产生磁场，这三个磁场合成得到一个旋转磁场。电流完成一次全振动，旋转磁场正好旋转一周，因此，旋转磁场的每分钟转数N=60f。式中f是电源频率。

交流电动机按转子旋转的速率可分为同步电动机和异步电动机（或称非同步电动机）两种。同步电动机不管负载大小，其转子转速恒与旋转磁场的转速相同，因此把这种转速叫做同步转速，如上所述，它只决定于电源的频率。异步电动机的转速则不是恒定的，它决定于负载的大小和电源电压。三相异步电动机中又有无整流子电机和有整流子电机之分。实际应用的异步电动机绝大多数是无整流器的感应电动机（但并联与串联的三相异步整流子电动机具有可在大范围内调节转速、有高功率因数等优点），它的转速恒小于同步转速。

Ac motor consists of stator and rotor, AC motor is divided into synchronous AC motor and induction motor two kinds. The stator side windings of both kinds of motors are fed alternating current to produce rotating magnetic field, but the rotor windings of synchronous AC motors usually require direct current (excitation current) to be supplied by the exciter. Induction motors, on the other hand, do not need to pass current through the rotor winding.

The stator windings of the three-phase AC motor are basically three coils separated 120 degrees from each other, and are connected in a triangle or star shape. When a three-phase current is passed, a magnetic field is generated in each coil, and the three magnetic fields are combined to produce a rotating magnetic field. The current completes a full vibration, and the rotating magnetic field rotates exactly once, so the revolutions per minute of the rotating magnetic field N=60f. Where f is the power supply frequency.

Ac motor according to the rotor rotation rate can be divided into synchronous motor and asynchronous motor (or asynchronous motor) two kinds. Synchronous motor regardless of the size of the load, the rotor speed is always the same as the rotating magnetic field speed, so this speed is called synchronous speed, as mentioned above, it is only determined by the frequency of the power supply. The speed of the asynchronous motor is not constant, it depends on the size of the load and the power supply voltage. The three-phase asynchronous motor is divided into a commutator motor and a commutator motor. The vast majority of asynchronous motors in practical application are induction motors without rectiters (but the three-phase asynchronous commutator motors in parallel and series have the advantages of adjusting the speed in a wide range and having high power factor, etc.), and its speed is always less than the synchronous speed.