Slip Ring Induction Motor Rotor

An induction motor is an electrical device that converts electrical energy into mechanical energy.

Slip ring induction motor rotor.

Slip ring induction motor is one of the types of 3 phase induction motor and is a wound rotor motor type. Induction motor rotor is of two types. Induction motors have been ruling the industrial world for many decades. A wound rotor motor also known as slip ring rotor motor is a type of induction motor where the rotor windings are connected through slip rings to external resistance.

The rotor is wound for the same number of poles as that of the stator. The main difference in a slip ring induction motor is on the rotor construction and usage. What is slip ring induction motor. The slip ring induction motor could be used for industrial wires where variable speed and high starting torque are prime requirements.

The motor which employing the wound rotor is known as a slip ring induction motor or phase wound motor. In a version of the ac induction motor referred to as a wound rotor motor slip rings are used not for transferring power but for inserting resistance into the rotor windings a wound rotor motor uses three slip rings typically made of copper or a copper alloy mounted to but insulated from the motor shaft. In the induction motors used in lift and hoists you will see a type of rotor called a slip ring rotor whereas in most of the other applications you will see a simpler squirrel cage type of rotor. It consists laminated cylindrical core which has a semi closed slot at the outer periphery and carries three phase insulated winding.

This external circuit helps in developing a high starting torque compared to a squirrel cage type. Adjusting the resistance allows control of the speed torque characteristic of the motor. It is most widely used for industrial applications due to its self starting attribute. Rotor as the name suggests it is a rotating part of an electrical machine in which current is induced by transformer action from rotating magnetic field.

Wound rotor motors can be started with low inrush current by inserting high resistance into the rotor circuit. As the motor accelerates. This rings attached with high resistance acts as an external circuit for the rotor. The stator of slip ring induction motor is very much the same as that of the squirrel cage induction motor but the construction of its rotor is very much different stator winding can be either star or delta connected depending upon the design.