The difference between single-phase asynchronous motor and three-phase asynchronous motor is as follows: single-phase motor is used in the life of ordinary residents with a voltage of 220 V; three-phase motor is used in industrial production with a voltage of 380 V;
The principle of operation is different between single-phase asynchronous motor and three-phase asynchronous motor. The analysis is as follows:
Single-phase asynchronous motor generally refers to a low-power single-phase asynchronous motor powered by a single-phase AC power supply (AC220V). This kind of motor usually has two phase windings on the stator, and the rotor is a common squirrel cage type. Different distribution of two-phase windings on the stator and different power supply conditions can produce different starting and operating characteristics.
In principle, when the single-phase sinusoidal current passes through the stator winding, the motor will produce an alternating magnetic field. The strength and direction of the magnetic field change with time sinusoidally, but it is fixed in spatial orientation, so it is also called alternating pulsating magnetic field. The alternating pulsating magnetic field can be decomposed into two rotating magnetic fields with the same rotating speed and opposite rotating direction. When the rotor is stationary, the two rotating magnetic fields produce two equal-sized and opposite-directional torques in the rotor, which make the synthetic torque zero, so the motor can not rotate.
Three-phase asynchronous motor refers to a rotating magnetic field generated when the three-phase stator windings (120 degrees electric angle of each phase difference) of the motor are connected to three-phase alternating current. The rotating magnetic field cuts the rotor windings and generates induced current in the rotor windings (the rotor windings are closed paths).
The working principle of three-phase asynchronous motor:
The current-carrying rotor conductor will generate electromagnetic force under the action of stator rotating magnetic field, thus forming electromagnetic torque on the axis of the motor, driving the motor to rotate, and the direction of rotation of the motor is the same as that of the rotating magnetic field. Motor is also known as motor, in the circuit with the letter "M" (old standard with "D"). Its main function is to generate driving torque, as a power source of electrical appliances or various machinery, the motor system is fully enclosed, fan-cooled, squirrel cage structure.
In single-phase asynchronous motors, two-phase electricity exists only in single-phase motors. It is formed by splitting single-phase into two windings. For example, one winding does not series capacitors, the other winding series capacitors. The phase difference of the current between the two windings is about 90 degrees, and a rotating magnetic field will be generated to make the motor work. The same single-phase electricity is supplied to the motor. There is only one line of fire, and there are no two lines of fire.
The three-phase electricity of three-phase asynchronous motor is mainly used as the power supply of the motor, that is, the load that needs to be rotated. Because the three phase differences of three-phase electricity are 120 degrees. The rotor will not get stuck.