To be very brief,
Harmonics are caused because of magnetising current flowing in the primary of transformer, which cause deaviation from the ideal sinusoidal waveform producing peaky currents in the primary. Due to this the core of the transformer gets saturated and the wave form produced in the secondary also gets distorted.
DOL(Direct Online starting) Star Delta starting Auto transformer starting Above methods are for squirrel cage induction motor Rotor resistance starting is used for wound rotor or slip ring induction motor
Because of the presence of the air-gap between stator and rotor in motor the magnetization current is much higher than that of a transformer in addition to the friction and windage losses due to the rotation of the rotor.
Because, the losses of IM is more due to the contribution of friction losses at shaft bearings and wind age losses in rotor air gap, this reduces the efficiency of the equipment, Since transforms is a static equipment zero mechanical loss so efficiency of the equipments in high .
In dc motors, the electric power is conducted directly to the armature (i.e., rotating part) through brushes & commutator. Hence, in this sense a dc motor can be called as a Conduction motor. However, in ac motors, the rotor does not receive any electric power by conduction but by induction in exactly the same way as the secondary of a two winding transformer receives its power from the primary. That is why such motors are called as Induction motors. An induction motor can be treated as a rotating transformer i.e., one in which primary winding is stationary but secondary is free to rotate.
A motor rotor rotates due to an interaction between magnetic fields of the rotor and stator, where either may use permanent magnets, electromagnets, or a combination of both to effect the interaction. This interaction is based on the principle of opposite attraction and like repulsion related to magnets. Either the rotor or stator creates an electromagnetic field, and the opposite component (rotor or stator) tries to attract and repel the appropriate magnetic poles to 'lock' position with the electromagnetic field. The magnetic field is 'rotated' electrically by applying voltage to different windings within the motor in sequence, and since the moving component always tries to lock position with the magnetic field, the rotor will constantly rotate while trying to align its magnetism.
1. Induction Motor has an air-gap but transformer has no air gap rather it is mutually link. 2. Induction Motor has high no-load current than transformer. 3. Induction Motor is a dynamic device. 4. Induction Motor has high power factor.
They are magnetically coupled--a current in one circuit induces a current in the other one in both a transformer and an induction motor.
Squirrel Cage motor is a kind of Induction Motor. The reason an induction motor sometimes refered to a rotating transformer is because the stator (Primary windings in a transformer), which is powered to set up a magnetic field induces a current in the armature coils (secondar coils in a transformer). However, instead of giving an electrical power output, the coil is short circuited to produce mechanical output (torque in this case)
Like transformer induction motor has stator winding(Primary winding) and rotor winding(Secondary winding) separated by an airgap.Rotor winding(generally Al bars) are short circuited at the end to produce torque for the rotation.Hence the name short circuited transformer.
In an induction motor, power is supplied to the rotor using a changing magnetic flux i.e. without any true conductive contact. Similarly, in a transformer, the power is transferred from the primary coil to the secondry one using a varying magnetic flux and the plates have no physical linkage. Hence, the similarity between an induction motor and a transformer is very basic i.e. they both use the phenomenon of electromagnetic induction to transfer power from one part to another.
induction motor has two control system one is stator control another rotor control And it comes under the category of asynchronous motors. The term induction is because the rotor of an a.c motor does not receive the electric power through conduction but by induction same as the secondary of the transformer receives the power from primary. And so an induction motor can also be called as a rotating transformer i.e. one in which primary is stationary and secondary is free to rotate.
The current flowing through a transformer's secondary is the current drawn by the load, so it will be exactly the same as the current flowing through your induction motor -assuming that is the load. Don't really understand the point of your question!
DOL(Direct Online starting) Star Delta starting Auto transformer starting Above methods are for squirrel cage induction motor Rotor resistance starting is used for wound rotor or slip ring induction motor
because transformer has primary and secondary windings only but in motor has stator has two windings and rotorAnswerIt could be something to do with the part that there are no moving parts!
Just like a transformer, the core losses are a combination of eddy current losses and hysteresis losses.
Because of the presence of the air-gap between stator and rotor in motor the magnetization current is much higher than that of a transformer in addition to the friction and windage losses due to the rotation of the rotor.
Because, the losses of IM is more due to the contribution of friction losses at shaft bearings and wind age losses in rotor air gap, this reduces the efficiency of the equipment, Since transforms is a static equipment zero mechanical loss so efficiency of the equipments in high .