In a DC machine, which of the following statement is true?a)Compensating winding is used for neutralizing armature reaction while interpose winding is used for producing residual fluxb)Compensating winding is used for neutralizing armature reaction while interpole winding is used for improving commutation.c)Compensating winding is used for improving commutation while interpole winding is used for neutralizing armature reactiond)Compensating winding is used for improving commutation while interpole winding is used for producing residual flux.Correct answer is option 'B'. Can you explain this answer?

Question

Answer

Compensating winding is placed at teeth of pole shoes and it's current is in series with armature current but such that it opposes the flux due to armature reaction. Thus it neutritises the effect of armature reaction and main pole flux get avoided from demagnetisation effect.            And Interpole winding is placed on Interpole ( close to brush ).This winding is also connected series to armature and it also neutritises the armature reaction flux    and and induces addition voltage that oppose reactance armature voltage and further improve in commutation.

Answer

B

Answer

The compensating windings consist of a series of coils embedded in slots in the pole faces. These coils are connected in series with the armature. The series-connected compensating windings produce a magnetic field, which varies directly with armature current. Because the compensating windings are wound to produce a field that opposes the magnetic field of the armature, they tend to cancel the cross magnetizing effect of the armature magnetic field.

Interpoles are similar to the main field poles and located on the yoke between the main field poles. They have windings in series with the armature winding. Interpoles have the function of reducing the armature reaction effect in the commutating zone. They eliminate the need to shift the brush assembly.

Answer

Answer:

In a DC machine, compensating winding and interpole winding are used to address specific issues related to armature reaction and commutation.

Compensating Winding:
- Compensating winding is used to neutralize the effect of armature reaction in a DC machine.
- When current flows through the armature winding, it produces a magnetic field that interacts with the main magnetic field generated by the field winding.
- This interaction between the armature and field windings leads to a distortion of the main magnetic field, causing a shift in the magnetic neutral axis.
- The shift in the magnetic neutral axis can result in various issues such as sparking, poor commutation, and increased armature reaction.
- Compensating winding is placed in the pole shoes of the DC machine and is connected in series with the armature winding.
- The compensating winding produces a magnetic field that opposes the armature reaction and helps in neutralizing its effect.
- By neutralizing the armature reaction, the compensating winding improves the commutation process and reduces sparking.

Interpole Winding:
- Interpole winding, also known as commutating or auxiliary winding, is used to improve the commutation process in a DC machine.
- During commutation, the current flowing through the armature coil undergoing commutation changes from positive to negative or vice versa.
- This change in current direction creates a reaction force called the reactance voltage, which opposes the current reversal and affects the commutation process.
- Interpole winding is placed on the pole faces of the DC machine, in between the main field poles.
- The interpole winding is connected in series with the armature winding and produces a magnetic field that helps in neutralizing the reactance voltage.
- By neutralizing the reactance voltage, the interpole winding improves the commutation process, reduces sparking, and ensures smooth current reversal.

Correct Statement:
- The correct statement is option 'B': Compensating winding is used for neutralizing armature reaction while interpole winding is used for improving commutation.
- This statement accurately describes the functions of both the compensating winding and interpole winding in a DC machine.

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