How does an electric motor work with AC power?
1 Answer
An electric motor works with AC (alternating current) power through a process known as electromagnetic induction. When an AC voltage is applied to the motor's winding, it creates a changing magnetic field in the stator (the stationary part of the motor) and the rotor (the rotating part of the motor). This changing magnetic field induces a flow of current in the rotor, which, in turn, generates a magnetic field in the rotor.
The interaction between the magnetic fields of the stator and the rotor causes a force that drives the rotor to rotate. This process is based on the principle of the magnetic field trying to align itself with the changing magnetic field produced by the AC voltage.
Here's a step-by-step explanation of how an AC electric motor works:
Stator: The stator contains the motor's winding, which consists of multiple coils of wire wound around the stator core. When an AC voltage is applied to the stator winding, it causes a time-varying current to flow through the coils.
Magnetic field generation: As the AC voltage changes polarity over time (positive to negative and vice versa), the current flowing through the stator winding also changes direction. This, in turn, creates a time-varying magnetic field around the stator coils.
Rotor: Inside the stator, there is a rotor, typically made of conductive material such as copper or aluminum. The rotor is either solid or made up of individual conducting bars connected by end rings (squirrel-cage rotor) or a coil wound on the rotor (wound rotor). The rotor is not connected directly to any power source but relies on induction to create its own magnetic field.
Electromagnetic induction: The changing magnetic field from the stator induces a flow of current in the rotor (either in the conducting bars or the rotor coil). This current, known as "eddy currents," generates its own magnetic field in the rotor.
Interaction of magnetic fields: The magnetic fields of the stator and rotor interact with each other, resulting in a force that tries to align the rotor's magnetic field with the stator's rotating magnetic field. This force causes the rotor to start rotating.
Continuous rotation: As the AC voltage continues to change polarity and the magnetic field in the stator keeps rotating, the rotor follows this rotating magnetic field and continues to rotate as long as the AC power is supplied.
By adjusting the frequency and voltage of the AC power, the speed and direction of the motor's rotation can be controlled. AC motors are commonly used in various applications due to their simplicity, reliability, and ease of speed control.
The interaction between the magnetic fields of the stator and the rotor causes a force that drives the rotor to rotate. This process is based on the principle of the magnetic field trying to align itself with the changing magnetic field produced by the AC voltage.
Here's a step-by-step explanation of how an AC electric motor works:
Stator: The stator contains the motor's winding, which consists of multiple coils of wire wound around the stator core. When an AC voltage is applied to the stator winding, it causes a time-varying current to flow through the coils.
Magnetic field generation: As the AC voltage changes polarity over time (positive to negative and vice versa), the current flowing through the stator winding also changes direction. This, in turn, creates a time-varying magnetic field around the stator coils.
Rotor: Inside the stator, there is a rotor, typically made of conductive material such as copper or aluminum. The rotor is either solid or made up of individual conducting bars connected by end rings (squirrel-cage rotor) or a coil wound on the rotor (wound rotor). The rotor is not connected directly to any power source but relies on induction to create its own magnetic field.
Electromagnetic induction: The changing magnetic field from the stator induces a flow of current in the rotor (either in the conducting bars or the rotor coil). This current, known as "eddy currents," generates its own magnetic field in the rotor.
Interaction of magnetic fields: The magnetic fields of the stator and rotor interact with each other, resulting in a force that tries to align the rotor's magnetic field with the stator's rotating magnetic field. This force causes the rotor to start rotating.
Continuous rotation: As the AC voltage continues to change polarity and the magnetic field in the stator keeps rotating, the rotor follows this rotating magnetic field and continues to rotate as long as the AC power is supplied.
By adjusting the frequency and voltage of the AC power, the speed and direction of the motor's rotation can be controlled. AC motors are commonly used in various applications due to their simplicity, reliability, and ease of speed control.