In this lecture, the process of commutation is explained with the help of a four loop DC machine.

Course title: Electrical Machines
Course Link:    • EE213  1a  Magnets, lines of flux, ...  

Commutation is the process of getting a DC voltage (unidirectional voltage ) out of a DC machine. The polarity of voltage induced in coils reverses as the sides of the coil mover from one pole face to another pole face, that is, the voltage induced in the coil is not unidirectional. Commutation converts this voltage into a unidirectional voltage.