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 does the rotor of the induction motor rotate in the same direction as the rotating magnetic field?
The polarity of these rotor poles is such that they are attracted to the poles of the stator’s magnetic field, so they cause the rotor to follow the rotating magnetic field around in the same direction as the rotating magnetic field in the stator.
How does an induction motor rotate?
The interaction between the two fields causes the rotor to turn. As the magnetic field alternates between the red and blue coils, it effectively rotates around the motor. The rotating magnetic field makes the rotor spin in the same direction and (in theory) at almost the same speed.
What determines the direction of rotation of an AC induction motor?
A single phase induction motor requires separate starting circuitry to provide a rotating field to the motor. The normal running windings within such a single-phase motor can cause the rotor to turn in either direction, so the starting circuit determines the operating direction.
What is rotor in induction motor?
Rotor as the name suggests it is a rotating part of an electrical machine, in which current is induced by transformer action from rotating magnetic field. Induction motor rotor is of two types: Squirrel Cage Rotor. Wound Type Rotor or Slip Ring Type Rotor.
When a motor is short circuited what causes the motor to still rotate?
A magnetic field with the poles facing out is produced in the rotor due to the stator induced current. This causes the rotor (motor shaft) to rotate. As long as the stator is supplied to a stable voltage supply, the motor shaft will continue to rotate. During a short circuit condition the system voltage will decay.
Why does the magnet rotate in an AC motor?
The rotating magnetic field is produced radially around the rotor by the varying currents in the stator windings. The rotating magnetic field induces eddy currents in the squirrel cage’s vertical bars causing it to rotate.
Why do motors rotate?
Large AC motors (used in things like factory machines) work in a slightly different way: they pass alternating current through opposing pairs of magnets to create a rotating magnetic field, which “induces” (creates) a magnetic field in the motor’s rotor, causing it to spin around.
Do induction motors have brushes?
AC induction motors have no brushes and have a much longer life expectancy. DC motor speed is controlled by varying the armature current, while AC motor speed control is achieved by varying the frequency of the alternating current, often with a variable frequency drive(VFD).
What are the applications of induction motor?
AC induction motors are the most common electric motors in the world. These simple, reliable and economical motors are found in refrigerators, washing machines and furnaces, as well as conveyors, pumps, winders, wind tunnels and other industrial equipment.
How do you determine the direction of rotation of a motor?
One way to test motor direction is to take your best guess on how to connect the leads, then run the motor and note the direction it spins. If you’re wrong, you undo two leads and swap the wires. Just to make sure, run the motor again. If it spins in the correct direction, you can then couple it to the load.
What direction does a motor turn?
Engine rotation is viewed from the flywheel of the engine, clockwise would be Right Hand, and counter-clockwise would be Left Hand. Since you usually cannot see the flywheel with the engine in the boat it can also be determined from the front of the engine.
What is rotor speed of 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 starter is 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.
What is the function of a rotor in a motor?
Rotors are the moving part in an Alternator that have permanent magnets that move around the Stator’s iron plates to generate an Alternating Current (AC). Rotors require existing motion to function, so only once the engine or turbine is already running will a Rotor work with a Stator to provide a charge.