As the motor accelerates.
Slip ring induction motor rotor resistance.
This method is not applicable to cage rotor induction motor.
Rotor resistance control is one among the various methods for the speed control of induction motor.
Name one disadvantage of slip ring induction motor and squirrel cage induction motor.
Definition of slip ring motor.
The motor which employing the wound rotor is known as a slip ring induction motor or phase wound motor.
Also rotor windings are connected through slip rings to external resistance.
We know that a motor uses an external high resistance circuit for producing high starting torque.
The disadvantages are high copper losses and the low torque.
Starting of slip ring induction motors.
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.
These motors are usually started with full line voltage applied across its terminals.
1 by varying external resistance.
In this method of speed control the rotor circuit resistance is varied by connecting a variable external resistance.
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.
Wound rotor motors can be started with low inrush current by inserting high resistance into the rotor circuit.
Also the slip necessary to generate maximum torque is directly proportional to the rotor resistance.
So by varying resistance after the motor has attained rated speed the slip value can.
It consists laminated cylindrical core which has a semi closed slot at the outer periphery and carries three phase insulated winding.
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.
For slip ring induction motors additional resistance can be coupled in series with the rotor circuit.
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.
It can also be employed for marginal speed control.
Speed control of slip ring induction motor.
The resistance of this motor depends upon the slip and independent of the torque.
A motor with a wound type rotor is known as a slip ring induction motor.
The speed of the wound induction motor can be controlled by connecting an external resistance in the rotor circuit through slip rings.
What is a slip ring induction motor.
Adjusting the resistance allows control of the speed torque characteristic of the motor.
