The rotor is a moving component of an electromagnetic system in the electric motor, electric generator, or alternator. Its rotation is due to the interaction between the windings and magnetic fields which produces a torque around the rotor’s axis.
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.”
What is stator and rotor of induction motor?
The stator is in the stationary electrical component. … The rotor is the rotating electrical component. It also consists of a group of electro-magnets arranged around a cylinder, with the poles facing toward the stator poles. The rotor is located inside the stator and is mounted on the AC motor’s shaft.
What are the different types of rotor used in induction motor?
There are two types of induction motor rotors:
- Squirrel-cage rotor or simply cage rotor.
- Phase wound or wound rotors. The motors that use this type of rotor are known as Slip-ring rotors.
What is rotor speed in induction motor?
Rotor speeds typically lie in the 120–210 m/s range, but mostly between 150 and 190 m/s, with a tendency to be higher with a smaller rotor diameter . Currently the smallest rotor diameter used industrially is 28 mm with rotor speed up to 150,000 rpm, though some machines can reach 160,000 rpm.
Why starters are used in induction motor?
The three phase induction motors are self-starting due to rotating magnetic field. But the motors show tendency to draw very high current at the time of starting. … Hence there should be a device which can limit such high starting current. Such a device which limits high starting current is called a starter.11 мая 2017 г.
Which motor is used in table fan?
Is armature and rotor same?
The armature is the winding to which the load is connected. In small generators, the field windings are often on the stator, and the armature windings are on the rotor. Most large machines, however, have a rotating field and a stationary armature. … Thus, the armature is the stator and the field is the rotor.
How do you test an induction motor rotor?
HIGH CURRENT ROTOR TEST – This test is performed by applying high current through the shaft of the rotor (rotor out of stator) and thermally scanning (infrared or thermoscan) the rotor O.D. searching for shorted laminations. These shorted laminations cause localized hot spots which cause uneven heating of the rotor.
What are the types of motor winding?
Types of Motor Windings
- Stator Winding. The slot on stator core of the three-phase motor winding carries stator winding. …
- Rotor Winding. In a motor, the rotating part is known as the rotor. …
- Lap Winding. Lap winding is the one kind of armature winding. …
- Wave Winding.
What are the two types of rotor?
Induction motor rotor is of two types:
- Squirrel Cage Rotor.
- Wound Type Rotor or Slip Ring Type Rotor.
What type of rotor is most commonly used in an induction motor?
What are the main parts of 3 phase induction motor?
The stator of the three-phase induction motor consists of three main parts :
- Stator frame,
- Stator core,
- Stator winding or field winding.
What is the formula of rotor speed?
The synchronous speed of the rotor in RPM N = 120f/P where f is the frequency of the stator current and P is the number of poles. The operating speed No = N – Ns where Ns is the slip speed. The frequency of the rotor current fr = Ns x P/120, so fr = 0 if the slip is zero.
What is 120 in motor speed formula?
The equation for calculating synchronous speed is: S = 120 f/P speed = constant (120) times frequency of power source (60 Hz) divided by number of poles used in the motor (P). Where does the 120 come from and what units does it have? There is RPM on one side and Cycles/second divided by #of poles on the other.
What is difference between induction motor and synchronous motor?
A three phase Synchronous motor is a doubly excited machine, whereas an induction motor is a single excited machine. The armature winding of the Synchronous motor is energized from an AC source and its field winding from a DC source. The stator winding of Induction Motor is energized from an AC source.