So to provide a higher value of rotor resistance in squirrel cage induction motor double bar double cage rotor is used in induction motor. The motive is to provide higher value of rotor resistance in such a manner that the rotor with its higher valued resistance provides higher torque and more efficiency.
What is the advantage of double cage?
The advantage of a double-squirrel cage motor is that it provides high starting torque and low starting current. How does a double-squirrel cage induction motor operate (i) at starting (ii) under running conditions ? A double-squirrel cage motor has two rotor windings, one inside the other.
What is the purpose of using deep bar cage rotors?
The Deep Bar Rotor in an induction motor is used to obtain high rotor resistance at starting and low rotor resistance at the running condition. A bar may be assumed to be made up of a number of narrow layers connected in parallel.
What is the purpose of a squirrel cage?
A synchronous motor may have a squirrel-cage winding embedded in its rotor, used to increase the motor starting torque and so decrease the time to accelerate to synchronous speed. The squirrel cage winding of a synchronous machine will generally be smaller than for an induction machine of similar rating.
Why rotor is used in induction motor?
A wound rotor motor is a variation of the three-phase induction motor, designed to provide high starting torque for loads with high inertia, while requiring very low current. Wound rotor motors are also referred to as “slip ring motors.” … During starting, this resistance is placed in series with the rotor windings.
What are the merits and demerits of double cage induction motor?
A double cage motor develops higher starting torque for low starting current and its rotor heating loss is more. Full load slip is higher than double cage rotor. It has higher efficiency. Slip and efficiency are lower than the single cage rotor.
What is the advantage of double squirrel cage induction motor?
It has high efficiency and good speed regulation. It gives higher starting torque. Lower starting current and are cheaper in cost. They are more robust and are explosion proof since the risk of sparking is eliminated by the absence of slip ring and brushes.
At what condition the skin effect in deep bar induction motor will be maximum?
The skin effect in a deep bar induction motor is maximum when rotor is at standstill.
What are the types of 3 phase induction motor?
Depending upon the type of rotor used the three-phase induction motor is classified as:
- Squirrel Cage Induction Motor.
- Slip Ring Induction Motor or Wound Rotor Induction Motor or Phase Wound Induction Motor.
Why are induction motor called asynchronous?
Because it runs at a speed less than synchronous speed. Because induction motor can not rotate at synchronous speed it always rotate less than synchronous speed. in short, induction motor never rotates at synchronous speed so it called asynchronous motor.
What are advantages of cage motors?
Squirrel Cage Induction motors are cheaper in cost compared to Slip Ring Induction motors. Requires less maintenance and rugged construction. Because of the absence of slip rings, brushes maintenance duration and cost associated with the wear and tear of brushes are minimized.
What is difference between squirrel cage and induction motor?
Key Differences Between Slip Ring & Squirrel Cage Induction Motor. The motor whose rotor is wound type such type of motor is called slip ring induction motor, whereas the squirrel cage motor, has a squirrel cage type rotor. … The starting torque of the slip-ring motor is high, whereas in squirrel cage motor it is low.
Why is it called a squirrel cage fan?
Squirrel Cage Blowers. A squirrel cage blower, also known as a centrifugal blower, is used to move air and gases in a variety of applications. This equipment is so named since its construction looks similar to that of a hamster wheel. … As the impeller rotates, the air surrounding it also rotates at the same speed.
What are the types of induction motor?
Types of Induction Motor: A Concise and Useful Guild
- Types of Induction Motors. Types of Single-Phase Induction Motors. Split Phase Induction Motors. 2&3. Capacitor Start and Capacitor Start Capacitor Run Induction Motors. Shaded Pole Induction Motors. Types of Three-Phase Induction Motors. Squirrel Cage Induction Motor. Slip-ring or Wound Rotor Induction Motor.
Is slip ring induction motor?
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.
What is rotor slip?
“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. Slip is required to produce torque.