6/24/2023 0 Comments Emc motorsThe torque produced by the motor in synchronous speed in due to hysteresis which is why it is named Hysteresis motor. Therefore, there is no eddy current or eddy current torque. At such speed, there is no relative motion between stator & rotor. The rotor ferromagnetic nature produces opposite magnetic poles due to the stator’s RMF & it starts behaving as a permanent magnet. Once the motor reaches the near synchronous speed, the stator’s rotating magnetic field pulls the rotor in synchronism. Due to the eddy current torque, the motor behaves as an induction motor. The eddy current generates torque along with the hysteresis torque due to the high hysteresis loss property of the rotor’s material. The stator’s rotating magnetic field induces eddy current in the rotor. The rotor is supported by a non-magnetic shaft. The rotor which is in a cylindrical shape is made of ferromagnetic material with high magnetic retentivity or hysteresis loss such as hardened steel. in a single-phase hysteresis motor, there is an auxiliary winding beside the main winding as in a reluctance motor. Such electric motors are operated using single-phase as well as three-phase AC supply. Such type of synchronous motor works on the principle of hysteresis loss or residual magnetism occurring in the rotor. What is Motor Starter? Types of Motor Starters and Motor Starting Methods.Why We Need to Install a Starter with a Motor?.Once the motor reach near synchronous speed, the auxiliary winding is disconnected & the rotor is locked in synchronism due to the rotor’s ferromagnetic nature trying to keeping itself in the less reluctance position inside the rotating magnetic field. The motor starts like an actual single phase induction motor using the auxiliary winding. It has a squirrel cage type rotor (with no windings) just like in an induction motor made of ferromagnetic material. The auxiliary windings in used for starting the motor. There are two types of stator windings i.e. It is a single-phase synchronous motor that works on the principle of generating torque based on the magnetic reluctance. They utilize squirrel cage rotors such as the one used in induction motor. the rotor does not require separate DC supply for generating magnetic flux. Such synchronous motor that does not require DC excitation i.e. They are used in industries for applications that require constant speed over a range of loads & require precise positioning in robotics. However, the rotor still needs an extra DC source for excitation. These motor does not need any special starting mechanism to decide its direction. The benefit of a three-phase alternating current is that it generates a rotating magnetic field in the stator while the arrangement of the phases decides the direction of the rotation. These synchronous motor runs on three-phase power supply. They are used in recording instruments, electric wall clocks. The speed of such a motor only depends on the supply frequency. its direction is unidentified, which is why there is an extra starting arrangement used for giving it a direction. Such motor can start in either direction i.e. The reason for using two phases is that a single phase cannot generate a rotating magnetic field. To be precise, it actually uses two-phase, the second one being derived from the first phase. Such synchronous motor runs on single-phase AC supply. The utilize wire wound rotor with commutator & brushes assembly to supply current to the rotor’s windings. This flux reacts with the revolving flux of the stator to generate rotation. ![]() The DC excitation means that the rotor has a separate DC supply to generate its own magnetic flux. ![]() Such synchronous motor requires DC excitation. Related Post: Difference between Synchronous and Asynchronous Motor.it uses a separate DC excitation to generate its own magnetic field. It is used for constant speed application & precision control.Ī synchronous motor has the same stator design as asynchronous motor & it generates a rotating magnetic field when supplied with input alternating current. ![]() The speed of such electric motors only varies with variation in supply frequency & remains constant upon varying loads. The AC motors are further classified into two types.Īs its name suggests, such AC motor has a constant speed called synchronous speed that only depends on the frequency of the supply current. The rotor (having its own magnetic field) follows the RMF & starts rotation. ![]() The basic working principle of AC motor is the rotating magnetic field (RMF) generated by the stator winding when an alternating current is passed through it. These electric motors are powered using a single-phase or three-phase alternating current. The AC electric motor converts AC (Alternating Current) electrical energy into mechanical energy.
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