How is motor flux calculated?
Flux cut by one conductor in one revolution = dΦ = PΦ …. (Weber), Number of revolutions per second (speed in RPS) = N/60. Therefore, time for one revolution = dt = 60/N (Seconds)
What is flux in DC machines?
When both the armature and the field windings are excited by a DC supply, current flows through the windings and a magnetic flux proportional to the current is produced. When the flux from the field interacts with the flux from the armature, it results in motion of the rotor.
What is flux switching motor?
Its motor characteristics are shown to be similar to those of a DC machine. … Control of the armature windings can be achieved with very simple electronic circuits resulting in a very low cost and reliable variable speed drive.
What will happen if the back EMF of a DC motor vanishes suddenly?
Detailed Solution. If back emf of a dc motor vanishes suddenly, motor circuit will try to retain back emf by drawing more current from supply. As the back emf vanishes zero, the whole supply voltage appears across armature and heavy current flows.
How is flux produced in dc motor?
Magnetic flux in DC machine is produced by field coils carrying current. This is called excitation. Field winding is connected in parallel with armature winding.
What is the purpose of Interpoles?
Interpoles. Interpoles are designed in DC motors to overcome the effects of the armature reactance and the self-induction of the machine. Most shunt and compound DC motors over one-half horsepower have interpoles located 90 electrical degrees from the main poles.
What is air gap in DC motor?
The air gap refers to an actual physical gap in an electric motor that separates the moving rotor and the stator core. This gap is a necessary part of motor design and the size of the air gap is one of the keys to motor performance and reliability.
How is flux produced in the alternator?
As it rotates between poles, it links the flux between a single pair of opposing poles. The magnetic circuit of the stator is thus a pair of triangles, each containing a field, an armature and a shared path through the rotor. … It is this reversal of flux that produces the alternating emf.