Can an induction motor have multi-winding?is it possible to load the motor both electrically and mechanically?

Question

Can an induction motor have multi-winding?is it possible to load the motor both electrically and mechanically?

Answer 1

I believe that the only induction motors that have only one winding are very simple shaded pole motors. Even in shaded pole motors, you might say that the single shorted turn of wire that formes the shaded pole constitutes a second winding.

Most single phase motors have a main winding and a starting winding.

Three phase motors have at least one winding for each phase.

Many motors have each winding divided into two parts to allow the motor to be connected for either of two operating voltages.

Some motors have extra windings to allow them to operate at various speeds by connecting them as 2-pole, 4-pole, 6-pole etc.

Windings are also divided into several coils to distribute the magnetic field rather than have it concetrated in a small area.

With regard to loading the motor both electrically and mechanially, one interpretation of that question would be asking if a transformer could be built into the motor to allow a low voltage power supply to be obtained from the motor. The answer to that is yes. This has been done to provide power for an electronic controller for a magnetic clutch furnished as part of the motor. That is probably a quite unsual thing to do. Most motor accessories that require power are connected to a separate source.

Another sense in which a motor might be loaded both mechanically and electrically is the case in which the motor acts as a generator drawing mechanical power from the load and returning electrical power to the source. With most motors, that requires a special type of electronic control system, but that feature is included with some percentage of electronic speed controls.

Another situation in which motors act as power sources is when a short circuit occurs in a power system. In that instance, current flows from connected motors to the short.

Edit 1

I forgot to mention wound rotor motors. They are induction motors with windings on both the stator and the rotor. The rotor windings are connected to slip rings for external connection of variable resistors for speed control. Electronic controls which return slip power to the power line can also be used. Doubly fed wound rotor motors can also be used in more complex configurations. Wound rotor motors are rarely used today.

Answer 2

An induction motor may be wired for two speeds but not more than two.The motor may be run either at low speed or high speed through a

contactor combination.