These are two principal methods by which the effect of armature reaction is overcome.
2.
This effect is known as armature reaction and is proportional to the current flowing in the armature coils.
3.
Without armature reaction, the magnetic neutral axis ( MNA ) would coincide with geometrical neutral axis ( GNA ).
4.
Armature reaction drop is the effect of a magnetic field on the distribution of the flux under main poles of a generator.
5.
The brush-setting method is the most common means of correcting for armature reaction in small generators ( those producing approximately 1000 W or less ).
6.
To avoid these situations, improved motors are assembled with forward brush-shifting that offsets the armature reaction during load operation to keep them on neutral electrically.
7.
Motors and generators suffer from a phenomenon known as'armature reaction', one of the effects of which is to change the position at which the current reversal through the windings should ideally take place as the loading varies.
8.
Armature reaction causes the neutral plane to shift in the direction of rotation, and if the brushes are in the neutral plane at no load, that is, when no armature current is flowing, they will not be in the neutral plane when armature current is flowing.
9.
The first method is to shift the position of the brushes so that they are in the neutral plane when the generator is producing its normal load current . in the other method, special field poles, called interpoles, are installed in the generator to counteract the effect of armature reaction.
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