For slip ring induction motors additional resistance can be coupled in series with the rotor circuit.
Slip ring induction motor rotor resistance.
1 by varying external resistance.
Adjusting the resistance allows control of the speed torque characteristic of the 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.
It can also be employed for marginal speed control.
So by varying resistance after the motor has attained rated speed the slip value can.
The resistance of this motor depends upon the slip and independent of the torque.
The motor which employing the wound rotor is known as a slip ring induction motor or phase wound motor.
As the motor accelerates.
As these motors have external resistance connected to its rotor circuit the value of starting current is adjusted or kept minimum by increasing the resistance of the rotor circuit.
Rotor resistance control is also one of the methods by which we can control the speed of the induction motor.
Rotor resistance control is one among the various methods for the speed control of induction motor.
The disadvantages are high copper losses and the low torque.
A motor with a wound type rotor is known as a slip ring induction motor.
Also the slip necessary to generate maximum torque is directly proportional to the rotor resistance.
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.
Wound rotor motors can be started with low inrush current by inserting high resistance into the rotor circuit.
These motors are usually started with full line voltage applied across its terminals.
We know that a motor uses an external high resistance circuit for producing high starting torque.
In this method of speed control the rotor circuit resistance is varied by connecting a variable external resistance.
What is a slip ring induction motor.
It has already been stated that this is a common method used to limit the starting current of such machines.
Also rotor windings are connected through slip rings to external resistance.
This method is only applicable for slip ring or wound rotor induction motor wrim.
Name one disadvantage of slip ring induction motor and squirrel cage induction motor.
Starting of slip ring induction motors.
But adding external resistance as in the case of a slip ring induction motor makes the rotor resistance high when starting thus the rotor current is low and the starting torque is maximum.
This method is not applicable to cage rotor induction motor.
The speed of the wound induction motor can be controlled by connecting an external resistance in the rotor circuit through slip rings.
