Induction motors Group HE 12 -2 Omar Aiganym

Induction motors Group HE 12 -2 Omar Aiganym Baimukhanbetova Nazilya

Induction motors are the motors in which the magnetic field in the rotor is induced by the field created by the current flowing in the stator windings.

In 1824, the French physicist François Arago formulated the existence of rotating magnetic fields, termed Arago's rotations, which, by manually turning switches on and off, Walter Baily demonstrated in 1879 as in effect the first primitive induction motor. The first alternatingcurrent commutatorless induction motors have been independently invented by Galileo Ferraris and Nikola Tesla, a working motor model having been demonstrated by the former in 1885 and by the latter in 1887.

The most common method of producing the self-starting characteristic in these motors is to create a revolving field similar to that found in three-phase motors by means of “splitting” the singlephase motors.

Advantages: Simplicity of production. The relative cheapness. High reliability in operation. Low operating costs. For possible inclusion in the circuit without any converters (for loads that do not need to adjust the speed).

Disadvantages: Small starting torque. Significant starting current. Low power factor. The difficulty of controlling the speed with the required accuracy. Maximum engine speed is limited by the frequency of the circuit (3000 rev / min). The strong dependence of (quadratic) electromagnetic torque of the supply voltage (voltage changes 2 times the torque is changed 4 times; in DPT torque depends on the supply voltage of the armature in the first degree, that is more convenient).

Thank you for your attention