Rotating Field and Winding, Demonstration

This lecture demonstrates the measurement of the rotating field in the air gap of an asynchronous motor using a small coil to measure the induced voltage, which is directly proportional to the magnetic field. By connecting the motor to a three-phase system, the instructor shows how the induced voltage varies with the coil position in the air gap, revealing the presence of four poles in the asynchronous motor. Additionally, the effect of the rotating field is illustrated by observing the rotation of a small ball and a brass tube in the air gap, showcasing how the asynchronous motor induces Foucault currents that generate a rotational force, and how changing the phase sequence can alter the direction of rotation.

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Related concepts (26)

MICRO-314: Actuators and Electromagnetic systems II

Les étudiants seront capables de modéliser, de simuler et de mesurer des actionneurs électromagnétiques et des moteurs électriques.

Principes de fonctionnement, construction, calcul et applications des moteurs electriques.

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A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric or hydrogen vehicles, or electric multiple unit trains. Traction motors are used in electrically powered railway vehicles (electric multiple units) and other electric vehicles including electric milk floats, trolleybuses, elevators, roller coasters, and conveyors, as well as vehicles with electrical transmission systems (diesel-electric locomotives, electric hybrid vehicles), and battery electric vehicles.

An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate force in the form of torque applied on the motor's shaft. An electric generator is mechanically identical to an electric motor, but operates with a reversed flow of power, converting mechanical energy into electrical energy.

An AC motor is an electric motor driven by an alternating current (AC). The AC motor commonly consists of two basic parts, an outside stator having coils supplied with alternating current to produce a rotating magnetic field, and an inside rotor attached to the output shaft producing a second rotating magnetic field. The rotor magnetic field may be produced by permanent magnets, reluctance saliency, or DC or AC electrical windings.

A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to the magnetic field. A permanent magnet's magnetic field pulls on ferromagnetic materials such as iron, and attracts or repels other magnets.