A two-phase motor (also called single-phase motor) and three-phase motor has three different points:
1, the two working principles are different:
(1) two-phase motor working principle: when a single-phase sinusoidal current through the stator windings, the motor will produce an alternating magnetic field, the magnetic field of the strength and direction of the sinusoidal law at any time between the changes in the spatial direction, but in the space orientation is fixed.
This alternating pulsating magnetic field can be decomposed into two to the same speed, the direction of rotation is the opposite of the rotating magnetic field, when the rotor is stationary, the two rotating magnetic field in the rotor to produce two equal size, the direction of the opposite torque, so that the synthetic torque is zero, so the motor can not rotate.
The movement of cutting magnetic lines of force between the rotor and the rotating magnetic field in the counterclockwise direction of rotation becomes larger. This breaks the equilibrium and the total electromagnetic torque produced by the rotor will no longer be zero and the rotor will spin up in the direction of propulsion.
(2) three-phase motor principle of operation: three-phase motor is when the motor's three-phase stator windings (each 120 degrees difference in the angle of electricity), into the three-phase alternating current, will produce a rotating magnetic field, the rotating magnetic field cutting rotor windings.
Thereby generating an induced current in the rotor winding (the rotor winding is a closed circuit), the current-carrying rotor conductor in the stator under the action of the rotating magnetic field will produce an electromagnetic force, thus forming an electromagnetic torque on the motor shaft to drive the motor rotation, and the direction of the motor rotation and the direction of the rotating magnetic field is the same.
2, the two AC power used by different:
(1) two-phase motor AC power: generally single-phase AC power (AC220V).
(2) three-phase motor AC power used: is a three-phase AC power supply.
3, the two definitions are different:
(1) the definition of two-phase motors: two-phase motors usually have two-phase windings on the stator, the rotor is an ordinary squirrel cage. The distribution of the two-phase windings on the stator and the difference in power supply can produce different starting characteristics and operating characteristics.
(2) the definition of three-phase motor: three-phase motor it refers to when the motor's three-phase stator windings (each phase difference of 120 degrees of electrical angle), through the three-phase alternating current, will produce a rotating magnetic field, the rotating magnetic field cutting rotor windings to generate electricity. It includes three-phase synchronous motors and three-phase asynchronous motors.
Two, two-phase motor application:
Two-phase motor not only in the production of large quantities, but also with people's daily life, closely related, especially with the people's living standards are increasingly improved, the use of single-phase motors for household appliances and equipment, but also more and more.
Applied in the production of micro-pumps, grinders, threshing machines, pulverizers, woodworking machinery, medical equipment, etc., in terms of life, there are fans, hair dryers, exhaust fans, washing machines, refrigerators, etc., a wider variety of types, but the power is smaller.
Baidu Encyclopedia - Three-Phase Motor
Baidu Encyclopedia - Three-Phase Motor
Baidu Encyclopedia - Single-Phase Motor