Table of Contents
Slip ring induction motor have big advantage of having high starting torque compared to squirrel cage motor. Therefore slip ring induction motors are generally employed where load requires high starting torque or good speed control.
What are the advantages of slip ring induction motor over cage induction motor?
High starting torque. It can be obtained by adding external resistance in the rotor circuit. Speed control by rotor resistance is possible. Less starting current compared to squirrel cage Induction Motor.
What is the main difference between a slip ring and a 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.
What are the advantages of wound rotor motor over squirrel cage motors?
Another important advantage over squirrel-cage motors is higher starting torque. The speed and torque characteristics of a wound-rotor motor can be adjusted by changing the external resistance, unlike a squirrel cage motor which has a fixed characteristic. This is useful for speed control of the motor.
What is the advantage of starting a slip ring induction motor with the help of rotor resistance as compared to other methods?
The slip ring induction motor has a high starting torque as the resistance of the rotor winding is increased by adding the external resistance to it. The starting torque is increased as the power factor of the rotor circuit gets improved during starting.
What are the applications of slip ring induction motor?
Slip ring induction motor is one of the types of 3-phase induction motor and is a wound rotor motor type. 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.
Which is better squirrel cage or slip ring?
The squirrel cage induction motor is the most popular type of AC motor. It is very commonly used in industries because it is very cheap, robust, efficient, and reliable.Comparison Chart. Basis For Comparison Slip Ring Motor Squirrel Cage motor Power Factor Low HIgh Cost Costly Cheap Starting Current Low High.
Why do we use slip rings in motors?
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.
Why are squirrel cage motors so reliable?
The interaction of the magnetic fields produced by the stator and rotor windings produces a torque on the squirrel cage rotor. Squirrel cage induction motors are used a lot in industry – as they are reliable, self-starting, and easy to adjust.
Why is it called a squirrel cage motor?
Squirrel cage motors are a subclass of induction motors, which harness electromagnetism to generate motion. They are so-called “squirrel cage” motors because the shape of their rotor – the inner component connected to the output shaft – looks like a cage.
What is the purpose of squirrel cage?
The main use of a squirrel-cage motor in a home HVAC system is that it powers the blower fan. If you have a forced-air heating system, such as a furnace, and/or an air conditioning system, the squirrel-cage motor is the part that turns the fans that blows the heated and cooled air through the ventilation system.
What is the advantage of wound rotor 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.
Why is the speed of the squirrel cage motor fixed?
‘Fixed’ speed induction generators Because the speed variation from no load to full load is very small, the term ‘fixed’ speed tends to be widely used. The design and construction of the stator and rotor of an induction generator are similar to that of a large induction motor having a squirrel-cage rotor.
What type of starter is used in slip ring induction motor?
Rotor resistance starter is used for slip ring induction motors of high ratings.
Which starting method is the best method in induction motor?
Starting of an Induction Motor Direct on-line starter. The direct on-line starter method, of an induction motor, is simple and economical. Star delta starter. The star delta starter method of starting three-phase induction motors is very common and widely used among all the methods. Autotransformer starter.
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.
What is the unit of slip in induction motor?
The slip value is equal to ‘1’ as the rotor in the motor is at rest & it will not equivalent to ‘0’. So while operating the motor, the synchronous speed is not equivalent to ‘N’ i.e, actual speed in a given time. This article discusses an overview of the slip in an induction motor.
What is the most common AC motor type?
Induction motor rotors are the most common type of AC motor and are used for various types of pumps, compressors, and other machines.
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.
Which motor has high starting torque slip ring or squirrel cage?
Slip Ring / Wound Rotor Induction Motor: Sr. No. Squirrel Cage Induction Motor 7) Higher efficiency. 8) Low starting torque. It has 1.5 time full load torque. 9) Speed control by rotor resistance is not possible. 10) Starting current is 5 to 7 times the full load current.
Why squirrel cage rotor is skewed?
Skewing. The conductors are often skewed slightly along the length of the rotor to reduce noise and smooth out torque fluctuations that might result at some speeds due to interactions with the pole pieces of the stator, by ensuring that at any time the same fraction of a rotor bar is under each stator slot.
Does squirrel cage induction motor have slip rings?
In the squirrel cage induction motor, brushes and slip rings do not require. In slip ring induction motor, brushes and slip rings are required or present. It requires low maintenance. It requires more maintenance due to the additional brushes.
