The induction motor is a type of electric motor that operates from two rotating magnetic fields. It is a device widely used in industrial activities, especially those involving the generation of electric power.
With a structure and operation considered simple, the three-phase induction motor is basically composed of a rotor (the moving part of the motor) and a stator (the fixed part) that operate simultaneously, in addition to a space between these two structures — which is called the air gap. Both rotor and stator are made of thin magnetic steel sheets in the form of a ring, which are treated to reduce magnetic field losses.
The stator remains fixed to the motor housing and its function is to conduct energy and transform it into electricity. The rotor, in turn, is a structure that rotates around its own axis, producing rotational movement and energy.
The structures of the rotor and stator are mounted from a common shaft, through which a three-phase winding passes, allowing the passage of the magnetic flux which, in turn, forms three interconnected symmetrical circuits. The result is a star or delta connection.
Types of three-phase motors
Three-phase motors can be asynchronous or synchronous. Asynchronous models are manufactured in different power and speed ratings to meet the standardized voltages of the electrical grid: 220V, 380V, 440V, or 760V. This type of motor is the most used in industries and offers better operating conditions than single-phase motors — which require assistance at startup.
Synchronous three-phase motors are machines that promote the transformation of received electrical energy into mechanical energy to move a particular motor or machinery.
