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Types of three phase induction motor rotor
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Types of three phase induction motor rotor


Squirrel cage rotor :

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•There are two types of three phase induction motor rotor one is squirrel cage rotor and second is wound rotor.

•About 80 to 90 percent of the rotor are squirrel cage rotor.

•It is simply consists of copper bars and metal ring each slots consists of copper bar.

•These copper bars and end ring are short circuited.

•Also the bars are slightly skewed for starting purpose or to decrease locking.

Wound rotor :

image

•Wound rotor is the type of three phase induction motor rotor.

•About 10 percent induction motor are wound rotor motor.

•It basically consists of laminated core and slipring and copper winding.

•The slipring is connected to external resistance.

•Speed control of three phase induction motor via rotor resistance control method is possible with this rotor.

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Advantages of three phase induction motor https://youtu.be/27OIOCKN05U

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Explain the construction of three phase induction motor with neat diagram.

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A three-phase cage induction motor is started by direct-on-line (DOL) switching at the rated voltage. If the starting current drawn is 6 times the full load current, and the full load slip is 4%, then ratio of the starting developed torque to the full load torque is approximately equal to 1.44

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A three-phase squirrel cage induction motor has a starting torque of 150% and a maximum torque of 300% with respect to rated torque at rated voltage and rated frequency. Neglect the stator resistance and rotational losses. The value of slip for maximum torque is 26.79%

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