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Key Differences Between Slip Ring & Squirrel Cage Induction Motor. For starting the slip ring motor the rotor resistance starter is used, whereas the slip ring motor does not require any starter. The starting torque of the slip-ring motor is high, whereas in squirrel cage motor it is low.
What is the difference between induction motor and slip ring motor?
In Squirrel cage induction motors the rotor is simplest and most rugged in construction. In slip ring induction motors the rotor is wound type. In the motor the slip rings, brushes are provided. Compared to squirrel cage rotor the rotor construction is not simple.
What is the advantage of slip ring induction motor?
Speeds can be adjusted in the case of slip ring (wound rotor) induction motor by inserting an resistance. Hence slip ring motors are considered as variable speed motors. Slip ring motors have high over loading capacity, smooth acceleration under heavy loads, and no abnormal heating during starting.
What is Construction difference between slip ring and squirrel cage induction motor?
1. The major difference between them is that the slip ring’s motor comes with an external circuit that controls the speed of a motor. On the other hand, the squirrel cage motor does not have any external circuit and it is not possible to add one since the motor bar is spotted permanently at the end of that ring.
Do induction motors have slip rings?
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. Adjusting the resistance allows control of the speed/torque characteristic of the motor.
Why slip ring is used in motor?
A slip ring is an electromechanical device that allows the transmission of power and electrical signals from a stationary to a rotating structure. A slip ring can be used in any electromechanical system that requires rotation while transmitting power or signals.
Can induction motor run at synchronous speed?
So, theoretically, the Induction motor can never run at synchronous speed. But due to the reduction of speed, again lag influx will be achieved, and the motor will continue to move at this speed due to flux difference between rotor and stator. In short, an induction motor cannot run at induction speed.
Which type of starter is used in a slip ring induction motor?
Rotor resistance starter is used for slip ring induction motors of high ratings.
What are the advantages and disadvantages of wound rotor induction motor?
Wound Rotor Induction Motor Qualities Excellent starting torque for high inertia loads. Low starting current compared to squirrel cage induction motor. Speed is the resistance variable over 50% to 100% full speed. Higher maintenance of brushes and slip rings compared to squirrel cage motor.
What are the applications of 3-phase induction motor?
Application of 3-Phase Induction Motors Pumps and submersible. Pressing machine. Lathe machine. Grinding machine. Conveyor. Flour mills. Compressor. And other low mechanical power applications.
Why is squirrel cage induction motor preferred?
Advantages of Squirrel Cage Induction Motor They are low cost. Require less maintenance (as there are no slip rings or brushes) Good speed regulation (they are able to maintain a constant speed) High efficiency in converting electrical energy to mechanical energy (while running, not during startup)Aug 19, 2020.
What are the applications of squirrel cage induction motor?
Squirrel cage induction motors are commonly used in many industrial applications. They are particularly suited for applications where the motor must maintain a constant speed, be self-starting, or there is a desire for low maintenance. These motors are commonly used in: Centrifugal pumps.
What is the importance of slip in a 3 phase induction motor?
Slip creates a relative speed between the RMF and rotor. That keeps a torque continuously acting on it when the motor is running. So what would happen if slip becomes zero? Bcoz there will be no relative speed between RMF and rotor, and which will stop inducing rotor current.
What is the principle of slip ring induction motor?
This motor runs on the principle of Faraday’s law of electromagnetic induction. When a stator winding is excited with an AC supply, the stator winding produces magnetic flux. Based on faraday’s law of electromagnetic induction, the rotor winding gets induced and generates a current of magnetic flux.
What happens if the slip of induction motor is 1?
This is the reason; slip is never zero in an induction motor. Slip = 1, means that rotor is stationary. Negative value of slip in induction motor can be achieved when the rotor speed is more than the synchronously rotating magnetic flux.
How does slip Help for rotation of induction motor?
“Slip” in an AC induction motor is defined as: As the speed of the rotor drops below the stator speed, or synchronous speed, the rotation rate of the magnetic field in the rotor increases, inducing more current in the rotor’s windings and creating more torque.
Is slip ring a commutator?
A commutator is a specialized slip ring typically used on Direct Current motors and electrical generators to transfer electrical power between the stationary housing and the rotating armature with the added purpose of reversing the electrical current direction.
What is motor slip formula?
Slip speed is the speed difference between the Synchronous speed and Rotor speed. Slip speed = Synchronous speed – Rotor speed = Ns -N. Slip, s = (Ns – N) / Ns.
What is slip formula?
If the revolving magnetic flux’s synchronous speed & the speed of rotor are Ns & Nr in the motor, then the speed among them can be equivalent to (Ns – Nr). So, slip can be determined as. S = (Ns – Nr) / Ns.
How do you control the speed of an induction motor?
Speed Control of Three Phase Induction Motor V / f control or frequency control. Changing the number of stator poles. Controlling supply voltage. Adding rheostat in the stator circuit.
What are the two types of induction motor?
Single-phase induction motors and three-phase induction motors are the two main types of induction motors.
Why synchronous motors are not self starting?
Above a certain size, synchronous motors are not self-starting motors. This property is due to the inertia of the rotor; it cannot instantly follow the rotation of the magnetic field of the stator. Once the rotor nears the synchronous speed, the field winding is excited, and the motor pulls into synchronization.
Which starter is used for slip ring induction motor for high ratings?
For slip ring induction motors with high ratings, a rotor resistance starter is utilised.
Which starter is suitable for 3 HP slip ring induction motor?
Solution: Slip ring induction motor Squirrel cage induction motor The rotor resistance starter can be used Rotor resistance starter cannot be used Starting torque is high Starting torque is low Brushes are present Brushes are absent Frequent maintenance is required Less maintenance required.
Which type of starter is used to start and run 3 phase slip ring induction motor?
The star delta starter method of starting three-phase induction motors is very common and widely used among all the methods. In this method, the motor runs at delta-connected stator windings.
