Figure 1 : Asynchronous machine Diagram
3 coupled enrollments as a star configuration or in triangular , they are powered by a system of equilibrium supply. it will result (FERRARIS theorem ) Of the creation of a sliding magnetic field in the gap of the machine . the sliding speed of the field compared to the stator is
Ωs = ωs / p
Where ωs indicates the pulsation of the tri-phased statoric power supply network ,
p is the number of coils in each coil ,
p therefor indicates the number of pair of poles ( one pair is constituted of the North pole and the South pole)
Remark :
The stator that is put on a variable field must be papered to limit the losses by Foucault currents.
The Rotor of the machine sports a coiling similar to the stator : tri-phased coiling of the same number of poles as the stator . those 3 coils are coupled in a star configuration and a short-circuit on themselves. this type of rotor is is called coiled , but it is possible to ideate a more basic rotor made up of conducting bars short-circuited by a conducting ring at each end. we could then show that this squirrel cage rotor behaves like a wound rotor. the rotor rotates at an angular speed Ω not to be confused with Ωs.
This electromagnetic function short-circuited on the winding will give rise to a current (cont the intensity is limited by the impedance of the latter). the intersection between the current and the sliding field will give rise to forces acting on the rotor strands whose moment relative to the axis of rotation will constitute the torque of the machine. We will argue that this torque only exists if the electromagnetic function is non-zero, that is to say if fr is non-zero: the rotor must not rotate in synchronism so that there is a couple of or the name of the asynchronous machine. .
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