The types and characteristics of three-phase asynchronous motor

Types of three phase asynchronous motor According to the different rotor structure,three-phase asynchronous motor can be divided into the cage and winding type two kinds.The cage rotor asynchronous motor has simple structure,reliable operation,light weight,cheap,has been widely used,its main drawback is that control difficult.According to the permanent magnet generator motor speed is different,can be divided into the high speed motor,motor at low speed,constant speed motor and speed regulating motor.Low speed motor is divided into geared motor,electromagnetic reducer motors,torque motor and claw pole synchronous motor,etc.Speed regulating motor in addition to the levels can be divided into constant speed motor and constant speed motor,variable speed motor and stepless variable speed motor,also can be divided into electromagnetic speed regulating motor,dc speed regulating motor,PWM variable frequency speed regulating motor and switched reluctance motor speed control.Wound rotor three-phase asynchronous motor rotor and stator is also set up a three-phase winding and through the slip ring,brush with external resistor connection.Adjust the rheostat resistance can improve the starting performance of the motor and adjust the speed of three-phase motor.Three-phase asynchronous motor features: Advantages: compared with the single phase asynchronous motor,three-phase asynchronous motor has simple structure,easy fabrication,the operating performance is good,and can save materials,the price is cheap.

Weakness: acmotor2.blogspot.com the lagging power factor,low light load power factor,high performance is a bit poor.The use of three-phase asynchronous motor Three-phase asynchronous motor power,mainly made of large motors.It is commonly used in three-phase power supply (Triple - phase power) of large industrial equipment.It is clear that three-phase asynchronous motor is used only for motor,rarely used as a generator is a synchronous motor used to generate electricity.For small power under 1 kw three-phase asynchronous motor,not only can run for three phase,but also can be used as a single phase operation.Because the induced current in three-phase asynchronous motor rotor winding is due to the rotor conductors are generated by the relative motion with magnetic field.Three-phase asynchronous motor rotor speed won't sync with rotating magnetic field,much less than the speed of a rotating magnetic field.If the speed of three-phase asynchronous motor rotor and the rotating speed of a rotating magnetic field into equal,so,there is no relative movement between magnetic field and rotor,conductor lines of magnetic force does motor laminationnot cut,so it won't be in the rotor winding induced potential and current,three- phase asynchronous motor rotor conductor in magnetic field will not be the effect of electromagnetic force and make the rotor rotation.So the three-phase asynchronous motor rotor rotating speed can't be with a rotating magnetic field The same,always less than the synchronous speed www.facebook.com/guohong.trading of a rotating magnetic field.But under the special operation mode (e.g.,power brake),three-phase asynchronous motor rotor speed can be greater than the synchronous speed.