Table of Contents
- 1 What is armature reaction and what is its effect on dc generator?
- 2 What is armature reaction and commutation?
- 3 How does armature reaction occur in DC generator?
- 4 What is armature function?
- 5 What is an armature reaction in a DC machine?
- 6 What are the adverse effects of armature reactions on DC generators?
What is armature reaction and what is its effect on dc generator?
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?
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 is armature in motor?
In electrical engineering, an armature is the component of an electric motor which carries alternating Current. The armature must carry Current, so it is always a conductor or a conductive coil, oriented normal to both the field and to the direction of motion, Torque (rotating machine), or force (linear machine).
What is armature reaction and their power factor?
The effect of Armature (stator) flux on the flux produced by the rotor field poles is called Armature Reaction. The power factor can be defined as the cosine of the angle between the armature phase current and the induced EMF in the armature conductor in that phase. …
How does armature reaction occur in DC generator?
What is Armature Reaction? In a dc generator, the magnetic flux is produced by the field coils when it is excited by a dc source. This field flux will be uniformly distributed along the air-gap of the machine and links with the conductors placed on the rotating armature.
What is armature function?
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 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 armature reaction voltage?
Armature reaction is defined as the effect of armature flux on the main flux produced by the field poles. Upon giving mechanical input and field excitation, the alternator generates the AC voltage by Faraday’s law of Electromagnetic induction.
What is an armature reaction in a DC machine?
In a DC machine, two kinds of magnetic fluxes are present; ‘armature flux’ and ‘main field flux’. The effect of armature flux on the main field flux is called as armature reaction.
What are the adverse effects of armature reactions on DC generators?
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 the effect of armature reaction on voltage?
As we discussed above that armature reaction decreases flux strength flux at one half of the pole and decreased at the second half. So the resulting flux is also less that decreases the output voltage. This effect is also called the demagnetizing effect as flux is reducing due to armature reaction.
What is cross magnetization and armature reaction?
This cross magnetization effect results in the concentration of flux at the trailing pole tip in generator action and at the leading pole tip in motor action. The armature reaction is the effect of the armature flux on the main flux.