To achieve this the rotor ac current is converted by means of a three phase.
Slip ring induction motor rotor current.
By the uses of slip ring in an induction motor we can easily control the speed of induction motor by adding an external resistance to the rotor.
The rotor winding is distributed as well short pitched to get a sinusoidal emf output.
The slip ring induction motor has two distinctly separate parts one is the stator and other is the rotor.
This reduces the phase difference angle and the current induced approaches the maximum torque condition.
It is controlled by varying the rotor current of the motor.
Definition of slip ring motor.
The function of a three phase slip ring induction motor is shown in the figure below.
As rotor current is directly proportional to the speed and torque of three phase ring type.
As a slip ring induction motor starts the external resistance value is increased fig 11.
Because of various advantages like low initial current high starting torque and improved power factor it is used in applications that require high torque cranes and elevators.
However no power is applied to the slip rings.
Slip rings i m provides some advantages like provides high starting torque low starting current and it improves the power factor.
A wound rotor motor uses three slip rings typically made of copper or a copper alloy mounted to but insulated from the motor shaft.
Adjusting the resistance allows control of the speed torque characteristic of the motor.
The stator circuit is rated as same in the squirrel cage motor but the rotor is rated in frame voltage or short circuit current.
This way slip ring induction motors will be able to produce high torque even as they are starting.
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.
Their sole purpose is to allow resistance to be placed in series with the rotor windings while starting figure below.
It consists laminated cylindrical core which has a semi closed slot at the outer periphery and carries three phase insulated winding.
Slip ring induction motor is one of the types of 3 phase induction motor and is a wound rotor motor type.
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.
