Commutation in DC Machine or Commutation in DC Generator or Motor

The voltage generated in the armature, placed in a rotating magnetic field, of a DC generator is alternating in nature. The commutation in DC machine or more specifically commutation in DC generator is the process in which generated alternating current in the armature winding of a dc machine is converted into direct current after going … Read more

Methods of Improving Commutation

To make the commutation satisfactory we have to make sure that the current flowing through the coil completely reversed during the commutation period attains its full value. There are three main methods of improving commutation. These are Resistance commutation E.M.F. commutation Compensating windings Resistance Commutation In this method of commutation we use high electrical resistance … Read more

Armature Reaction in DC Machine

In a DC machine, the carbon brushes are always placed at the magnetic neutral axis. In no load condition, the magnetic neutral axis coincides with the geometrical neutral axis. Now, when the machine is loaded, the armature flux is directed along the inter polar axis (the axis in between the magnetic poles)and is triangular in … Read more