## What is the effect of armature reaction on performance of synchronous machine?

Due to armature reaction, flux is reduced or distorted, the net emf induced is also affected and hence the performance of the machine degrades.

## What are the effects of armature reaction?

The current flowing through the armature conductors creates a magnetic field, which is called as armature flux. This armature flux distorts and weakens the magnetic flux produced by the main poles. This effect of armature flux on the main flux is known as armature reaction.

What is the effect of armature reaction at different power factors on synchronous machine?

The effect of the armature reaction depends on the magnitude of armature current and on the power factor of the load. The power of the load determines whether the armature flux distorts, opposes or assists the main field flux.

### How does armature reaction affect the functioning of the machine?

The armature reaction changes the distribution of the magnetic field, which affects the operation of the machine. The effects of the armature flux can be offset by adding a compensating winding to the main poles, or in some machines adding intermediate magnetic poles, connected in the armature circuit.

### For which value of power factor the effect of armature reaction is maximum?

ωt = 0
Hence, at ωt = 0, E is maximum and φf is zero.

What is armature reaction?

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.

#### How the effect of armature reaction can be reduced?

1) The armature reaction causes the distortion in main field flux. This can be reduced if the reluctance of the path of the cross-magnetizing 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.

#### Is armature reaction good or bad?

Due to the above two effects of armature mmf, there are many detrimental effects on the Electrical machine. Distortion of Main Field Flux gives rise to three detrimental effects: Rise in Iron Loss, Poor Commutation and Sparking in Carbon Brushes.

What is meant by armature reaction in synchronous machine?

The effect of Armature (stator) flux on the flux produced by the rotor field poles is called Armature Reaction. When the current flows through the armature winding of the alternator, a flux is produced by the resulting MMF.

## How does armature reaction affect the torque of a DC motor?

The armature reaction in the motor affects the torque speed characteristics of the motor. Due to the armature reaction in the motor the shape of the torque speed characteristics will changes.

What is meant by armature reaction of a synchronous machine?

The effect of Armature (stator) flux on the flux produced by the rotor field poles is called Armature Reaction.