SYNCHRONOUS MACHINES

Armature winding of synchronous machine either delivers 3 phase a.c source or its supplied by 3 phase a.c source and the field winding is energized from dc source. As in other rotating machine the emf induced in synchronous machine is motional emf so there must be relative motion between the conductors and magnetic field. Emf […]

LOSSES AND EFFICIENCY

Induction Motor Even if the machine is lossless we cannot ignore the electrical portion of airgap power which When we subtract friction and windage losses from the developed power then we obtain the shaft power. In Induction machine we do not merge core loss and mechanical loss as rotational loss because there location inside the […]

ROTOR (Equivalent Circuit)

Under running condition the rotor frequency is scaled by a factor of “s” due to which all the parameters that are directly proportional to frequency such as emf and reactance also scaled by a factor of “s”. We considered the resistance to be independent of the frequency hence the rotor resistance remain same under standstill […]

Rotor Construction Of an Induction Motor Squirrel Cage Rotor

Silicon steel is used for stator as well as rotor construction and in rotor as well as stator it is laminated to reduce eddy current losses. The stator frequency is generally higher then rotor frequency hence to reduce eddy current loss we make use of thinner lamination in stator and thicker lamination in rotor The […]