14 Facts About Induction motor

1.

An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding.

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2.

Furthermore, he claimed that Tesla's Induction motor was not practical because of two-phase pulsations, which prompted him to persist in his three-phase work.

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3.

Induction motor improvements flowing from these inventions and innovations were such that a 100-horsepower induction motor currently has the same mounting dimensions as a 7.

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4.

Since rotation at synchronous speed would result in no induced rotor current, an induction motor always operates slightly slower than synchronous speed.

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5.

An induction motor can be used as an induction generator, or it can be unrolled to form a linear induction motor which can directly generate linear motion.

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6.

Therefore, it is necessary to either snap the Induction motor and connect it momentarily to a live grid or to add capacitors charged initially by residual magnetism and providing the required reactive power during operation.

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7.

In capacitor-start designs, the second winding is disconnected once the Induction motor is up to speed, usually either by a centrifugal switch acting on weights on the Induction motor shaft or a thermistor which heats up and increases its resistance, reducing the current through the second winding to an insignificant level.

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8.

Available squirrel-cage induction motor starting methods include direct-on-line starting, reduced-voltage reactor or auto-transformer starting, star-delta starting or, increasingly, new solid-state soft assemblies and, of course, variable frequency drives .

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9.

Large slip ring Induction motor drives, termed slip energy recovery systems, some still in use, recover energy from the rotor circuit, rectify it, and return it to the power system using a VFD.

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10.

Vector control allows independent control of the speed and torque of the Induction motor, making it possible to maintain a constant rotation speed at varying load torque.

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11.

Since an open, drip proof Induction motor design allows a free air exchange from outside to the inner stator windings, this style of Induction motor tends to be slightly more efficient because the windings are cooler.

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12.

Method of changing the direction of rotation of an induction motor depends on whether it is a three-phase or single-phase machine.

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13.

The equivalent circuit is a single-phase representation of a multiphase induction motor that is valid in steady-state balanced-load conditions.

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14.

Paraphrasing from Alger in Knowlton, an induction motor is simply an electrical transformer the magnetic circuit of which is separated by an air gap between the stator winding and the moving rotor winding.

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