Rotor winding of three-phase asynchronous motor

Function: Cutting the stator rotating magnetic field generates induced electromotive force and current, and forms electromagnetic torque to make the motor rotate.

Structure: Divided into squirrel cage rotor and wound rotor.

1) Squirrel cage rotor: The rotor winding consists of multiple guide bars inserted into the rotor slot and two circular end rings. If the rotor core is removed, the entire winding looks like a squirrel cage, so it is called a cage winding. Small cage motors use cast aluminum rotor windings. For motors over 100KW, copper bars and copper end rings are welded together.

2) Wound rotor: similar to the stator winding, the wound rotor winding is also a symmetrical three-phase winding. It is generally connected in a star shape. External circuit connection.

Features: The structure is more complex, so the application of the wound motor is not as wide as the squirrel cage motor. However, additional resistors and other components are connected in the rotor winding circuit through the collector ring and brushes to improve the starting and braking performance and speed regulation performance of the asynchronous motor. Therefore, smooth speed regulation equipment within a certain range is required, such as Used on cranes, elevators, air compressors, etc.