Three-phase Asynchronous Motor Induction Motor

Three-phase asynchronous motor, also called a three-phase induction motor, operates on the principle of electromagnetic induction discovered by Nikola Tesla. The stator of the three-phase asynchronous motor is powered by three-phase alternating current at 400V/50Hz and generates a rotating magnetic field with a synchronous speed dependent on the frequency and number of poles.

This rotating magnetic field induces electric currents in the rotor (either squirrel cage or wound) which in turn create a second magnetic field. The interaction between the two fields produces the mechanical torque that turns the motor shaft. The term „asynchronous” comes from the fact that the rotor rotates at a slightly slower speed than the stator magnetic field – the difference is called „slip”.

The three-phase asynchronous motor is the most widespread type of industrial electric motor in the world, representing over 80% of the installed motors. Main advantages: simple and robust construction, lack of electrical contacts in the rotor, long life, minimal maintenance, high reliability and low cost.