[¦krȯs ′mag·nə‚tīz·iŋ i′fekt] (electromagnetism) The distortion in the flux-density distribution in the air gap of an electric rotating machine caused by armature reaction.
What do you mean by cross magnetization?
Cross-magnetisation is the behaviour of machine mag- netic materials in which the main driving magnetomotive. force (MMF) is not applied in the geometrically favoured. direction of the magnetic component, so that there is some. magnetisation of the component across the favoured.
How can cross magnetizing effect be reduced?
Compensating winding With every change in load, the cross magnetizing effect of armature reaction will have a serious issue in larger machines. So it is very important to minimize those effects. There comes the use of compensating windings. The compensating winding is a winding embedded in slots in the pole shoes.
What is cross Magnetising effect of armature reaction?
The cross magnetizing armature reaction effect is mainly caused by armature conductors which are located under the pole arc. At high loads, this effect of armature reaction may cause excessive flux density in the trailing pole tip (in generator) and leading pole tip (in motor).
What is the magnetization effect?
Magnetization effects in matter are discussed in some detail below. The permeability μ is often used for ferromagnetic materials such as iron that have a large magnetic susceptibility dependent on the field and the previous magnetic state of the sample; permeability is defined by the equation B = μH.
What is meant by demagnetizing effect and cross magnetizing effect?
The opposition of armature flux on the main field flux is called armature reaction. This armature reaction has two undesirable effects, either it weakens (reduces) the main field flux called ‘Demagnetising Effect’ or it distorts the main field flux called ‘Cross-magnetising Effect’.
What are the effects of de magnetization?
The term demagnetizing field reflects its tendency to act on the magnetization so as to reduce the total magnetic moment. It gives rise to shape anisotropy in ferromagnets with a single magnetic domain and to magnetic domains in larger ferromagnets.
What is magnetizing effect?
Once the generator is loaded, load current flows through the armature conductors and set up its own flux. This armature reaction has two undesirable effects, either it weakens (reduces) the main field flux called ‘Demagnetising Effect’ or it distorts the main field flux called ‘Cross-magnetising Effect’.
Which method limits cross magnetizing effect?
Which method needed to limit cross-magnetizing effect? Explanation: By ultimately increasing the reluctance of the magnetic circuit at the pole tips so that the armature reaction effect is neutralized.
What are demagnetizing and cross magnetizing effect?
Which method limits cross Magnetising effect?
What is the importance of magnetization?
Despite its magnetic field, Earth is losing its atmosphere to space at about the same rate as planets that lack this protective barrier against the solar wind.
How to minimize the cross magnetizing effect of armature reaction?
With every change in load, the cross magnetizing effect of armature reaction will have a serious issue in larger machines. So it is very important to minimize those effects. There comes the use of compensating windings. The compensating winding is a winding embedded in slots in the pole shoes.
Why are conductors called cross magnetizing conductors?
Since these fluxes are responsible for distorting the main field flux, the conductors are called as cross magnetizing conductors and constitute the cross magnetizing ampere-turns of armature reaction.
What are the effects of the armature flux?
The armature flux produces two effects: 1 demagnetizes or weakens the main field flux (Demagnetization effect) 2 cross magnetizes or distorts the main flux (Cross magnetization effect) More
What is MNA (magnetic neutral axis)?
Magnetic Neutral axis (MNA) is the axis along which no emf is induced in the armature conductors, as they move parallel to the magnetic field. It is an axis, which is perpendicular to the flux passing through the center of the armature.
