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A wound-rotor motor, also known as slip ring-rotor motor, is a type of induction motor where the rotor windings are connected through slip rings to external resistance. Adjusting the resistance allows control of the speed/torque characteristic of the motor.
Constant air-gap induction motor equivalent circuit The circle diagram (also known as Heyland diagram or Heyland circle ) is the graphical representation of the performance of the electrical machine [ 1 ] [ 2 ] [ 3 ] drawn in terms of the locus of the machine's input voltage and current. [ 4 ]
An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor that produces torque is obtained by electromagnetic induction from the magnetic field of the stator winding. [1] An induction motor therefore needs no electrical connections to the rotor.
The motor always turns slightly slower than the synchronous speed. The difference between synchronous and operating speed is called "slip" and is often expressed as percent of the synchronous speed. For example, a motor operating at 1450 RPM that has a synchronous speed of 1500 RPM is running at a slip of +3.3%. In operation as a motor, the ...
By adjusting the shape of the bars in the rotor, the speed-torque characteristics of the motor can be changed, to minimize starting current or to maximize low-speed torque, for example. Squirrel-cage induction motors are very prevalent in industry, in sizes from below 1 kilowatt (1.3 hp) up to tens of megawatts (tens-of-thousand horsepower).
The induction motor (or asynchronous motor) always relies on a small difference in speed between the stator rotating magnetic field and the rotor shaft speed called slip to induce rotor current in the rotor AC winding. As a result, the induction motor cannot produce torque near synchronous speed where induction (or slip) is irrelevant or ceases ...
A linear induction motor (LIM) is an alternating current (AC), asynchronous linear motor that works by the same general principles as other induction motors but is typically designed to directly produce motion in a straight line. Characteristically, linear induction motors have a finite primary or secondary length, which generates end-effects ...
The rating of a brushless motor is the ratio of the motor's unloaded rotational speed (measured in RPM) to the peak (not RMS) voltage on the wires connected to the coils (the back EMF). For example, an unloaded motor of K v {\displaystyle K_{\text{v}}} = 5,700 rpm/V supplied with 11.1 V will run at a nominal speed of 63,270 rpm (= 5,700 rpm/V ...