Circle Diagram of an Induction Motor

The Circle Diagram of an Induction motor is very useful to study its performance under all operating conditions. The construction of the circle diagram is based on the approximate equivalent circuit shown below. It is the diagrammatic representation of the performance of the induction motor. The circle diagram provides information about the power output, losses, …

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Pole Changing Method

Pole Changing Method is one of the main methods of the speed control of an induction motor. This method of controlling the speed by pole changing is used mainly for cage motor only because the cage rotor automatically develops a number of poles, which is equal to the poles of the stator winding. The number …

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Cogging in Induction Motor

The phenomenon of Magnetic Locking between the stator and the rotor teeth is called Cogging or Teeth Locking. Even after applying full voltage to the stator winding, the rotor of a 3 phase induction motor fails to start. This condition arises when the number of stator and rotor slots are either equal or have an …

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Deep Bar Rotor

The Deep Bar Rotor in an induction motor is used to obtain high rotor resistance at starting and low rotor resistance at the running condition. The figure below shows a deep bar cage rotor with deep and narrow bars: A bar may be assumed to be made up of a number of narrow layers connected …

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