What is armature reaction of dc machine?

The armature reaction is the effect of the armature flux on the main flux. In case of a DC motor the resultant flux is strengthened at the leading pole and weakened at the trailing pole tips.

What is armature reaction explain in detail?

Definition of armature reaction : a magnetomotive force set up by the current induced in the armature of a dynamo that results in altering as to both magnitude and direction the flux due to the field magnet.

What is armature reaction describe the effects of armature reaction on the operation of dc machines?

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 is armature reaction and commutation in a dc machine?

The action of armature flux on the main flux is called armature reaction. In the previous chapter (Sec 1.19), it was hinted that current in the coil is reversed as the coil passes a brush. This phenomenon is termed as commutation.

What are the types of armature reaction?

Types of Armature-Reaction

Demagnetization of the stator field.
The cross magnetization of the stator field.

What is 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.

What is armature reaction How does it affect the operation of a de 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.

What is armature reaction and types?

Types of Armature-Reaction The armature-reaction is one kind of magnetic field effect which is occurred by the flow of current throughout the armature conductors over the stator magnetic field.

What is the armature of a dc motor?

A DC motor has coils of wire mounted in slots on a cylinder of ferromagnetic material, which is termed the armature. The armature is mounted on bearings and is free to rotate. It is mounted in the magnetic field produced by permanent magnets or current passing through coils of wire, which are called the field coils.

What is the function of armature?

Armature – It is a rectangular coil that is placed in a uniform magnetic field. The main function of the armature is to rotate the shaft or axel to which it is attached. Brushes – They are attached (not fixed) to the split rings.

What are armature reaction and mention two methods to eliminate it in dc machines?

By using high reluctance pole tips, reduction in armature flux and using strong main field flux poles we neutralize the armature reaction. These compensating winding are of concentric type and are placed in axial slots in the pole faces.

What is armature reaction explain various scenarios of armature reaction in synchronous generator?

As soon as current starts flowing through the armature conductor there is one reverse effect of this current on the main field flux of the alternator (or synchronous generator). In other words, the effect of armature (stator) flux on the flux produced by the rotor field poles is called armature reaction.