## How can the effects of armature reaction be overcome?

3) The effect of armature reaction can be neutralized by use of compensating winding.

1. It is always placed in series with armature winding.
2. The armature ampere conductors under pole shoe must be equal to compensating winding ampere conductors which will compensate armature m.m.f. perfectly.

## Can the effects of armature reaction is serious?

The adverse effects of armature reaction: Armature reaction weakens the main flux. In case of a dc generator, weakening of the main flux reduces the generated voltage. Armature reaction distorts the main flux, hence the position of M.N.A. gets shifted (M.N.A. is perpendicular to the flux lines of main field flux).

What causes armature reaction?

The reaction caused by armature magnetomotive force is usually called armature reaction. The effect of armature magnetic field on the main magnetic field will distort the main magnetic field and produce armature reaction: The armature magnetic field distorts the main magnetic field, half strengthens and half weakens.

### Which of the following are the effects of the armature reaction?

Demagnetization effects which of the following? Demagnetization is one of the effect of armature reaction. By vector addition it is found that it reduces or weakens the main field flux. So it reduces the induced emf or terminal voltage in case of generator because Eg is directly proportional to the flux (φ).

### What are the methods used to reduce armature reaction?

The armature reaction causes the distortion in main field flux. This can be reduced if the reluctance of the path of the cross-magnetising field is increased. The armature teeth and air gap at pole tips offer reluctance to armature flux. Thus by increasing length of air gap, the armature reaction effect is reduced.

What is armature reaction explain?

Armature reaction is the effect on the main field flux of that flux set up by the currents in the armature winding. This is the flux distribution existing when the generator is on no load and it is seen to be symmetrically distributed with respect to the poles.

#### What is the effect of demagnetizing component of armature reaction?

Explanation: When the armature of a dc machine carries current, the distributed armature winding produces its own mmf (distributed) known as armature reaction. The demagnetizing component acts in the opposite direction, reducing flux/pole in a machine, which will ultimately reduce generator emf.

#### What is armature reaction in a dc machine?

3.10 Armature reaction in d.c. generators. Armature reaction is the effect on the main field flux of that flux set up by the currents in the armature winding. The effect is the same for both lap- and wave-wound machines.

What is armature reaction and its effect?

Definition: The armature reaction simply shows the effect of armature field on the main field. In other words, the armature reaction represents the impact of the armature flux on the main field flux. The armature reaction distorted the main field flux. It reduces the magnitude of the main field flux.

## How do you calculate armature reaction?

Estimation of Armature Reaction Constants

1. Rotate the machine at a constant speed (w1) using a prime mover. Keep the field current (If) constant.
2. Keep the speed constant at (w1) for all cases.
3. From the test results, calculate the armature reaction, AR, for different values of Ia and If.

## What are components of armature reaction?

Armature Winding and Armature Reaction The armature winding has some of the basic terms namely turn, coil and winding. Armature reaction is the result of the armature flux on top of main field flux. Generally, the DC motor includes two windings such as Armature winding as well as field winding.

How are the effects of the armature reaction reduced?

The armature reaction causes the distortion in main field flux. This can be reduced if the reluctance of the path of the cross-magnetising field is increased. The armature teeth and air gap at pole tips offer reluctance to armature flux. Thus by increasing length of air gap, the armature reaction effect is reduced.

### How does a compensating winding reduce the armature reaction?

The compensating winding are basically used to neutralize the armature flux in the pole arc region which will otherwise cause sever distortion of main field flux. By using high reluctance pole tips, reduction in armature flux and using strong main field flux poles we neutralize the armature reaction.

### How does the armature affect the main field?

When the generator is loaded, the armature carries the current. The armature current sets up its own magnetic field. The effect of this armature flux on the distribution of main field flux is called Armature Reaction. It reduces the generated voltage by distorting the main flux and it causes sparking at the brushes.

What causes the armature reaction in a DC machine?

Armature Reaction refers to a phenomenon in DC machines where the magnetic field of the poles is distorted by the magnetic field produced by the armature current. 1) The armature reaction causes the distortion in main field flux.