DGVCL Exam Paper (11-12-2011)
A 3 phase, 6 pole induction motor operates on 440 V, 50 Hz, supply. If the actual speed of the motor is 960 rpm the slip will be
under steay state: P= (E V sinδ)/ X change in load on motor, δ adjust to new value rotor oscillate about its final equilibrium load angle called hunting. cause: sudden change in load fault in supply system sudden change in field current remedies: using flywheel using damper bar
Skin Effect: tendency of the current to crowd near the conductor surface.
Skin effect is proportional to frequency, conductor diameter and permiability. Skin effect increases effective resistance of conductor. In DC, no skin effect.
EXAMIANS