What is the principle and difference of dc motor and ac motor?


The full and detailed answer to this question can be written in half a book.The brief explanation is as follows: the rotating motor generates torque through the magnetic field to the coil.The motor is mainly divided into dc motor and ac motor, and ac motor is divided into synchronous motor and asynchronous motor.(the permanent magnet motor does not discuss for a while) the alternating current itself is alternating, and the three-phase alternating current in the stator coil of ac motor can generate a rotating magnetic field.The rotor produces torque under the action of rotating magnetic field.(the difference between specific induction motor and synchronous motor won't start speak) by direct current (dc) motor stator, rotor on the brush and commutator, caused the rotor magnetic field direction change constantly, thus produce torque.You don't have to know much about how the motor works if you learn mechanics, which is a rather complicated theoretical system.If the motor is used as the driving force, it is necessary to know how to control the speed of the motor by controlling the device.dc motor

2. AC Rotary machines mainly include asynchronous motor and synchronous motor.U use: asynchronous motor is mainly used as a motor, one of the most widely used motor, industrial enterprises, transportation, entertainment, scientific research, agricultural production, daily life is inseparable from the asynchronous motor.There are three main types of asynchronous motors: squirrel-cage asynchronous motor, winding asynchronous motor and various kinds of control motor.Squirrel cage asynchronous motor: if the capacity of the power supply transformer is not large enough, it will be started by reducing pressure.Since the torque is reduced according to the gauge of the voltage square, this method is suitable for situations where the torque requirement is not high.Winding asynchronous motor: the start torque is greatly reduced by reducing the starting current.In applications where greater torque is required, people have to choose expensive winding asynchronous motors.The characteristic of the wound asynchronous motor is that it can be connected with the additional resistance in the rotor circuit to improve its start-up and speed regulation performance.In the rotor winding external series frequency sensitive varistor (BP for its code name)

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