Electrical Machines - EE 213 - 21 - Solutions to problems with commutation - Brush shifting and interpoles

This lecture explains two possible solutions, that is, brush shifting and interpoles to resolve the problems of commutation in DC machines. Course title: Electrical Machines Course Link: https://www.youtube.com/watch?v=ERLT2Kc6iYw&list=PL9s6YpaXIcJt1IeX3JV1z1j1E9JUi3bFj Brush shifting overcomes, to some extent, the problem of neutral plane shift in DC machines due to armature reaction. However, it cannot handle the problem of flux weakening and voltage kickback effects. Furthermore, one the brushes are relocated for operation of the machine as a motor, this machine can no more be operated as a generator, and vice versa. However, this is a less expensive solution utilized in small DC machines. Interpoles resolve the problem of neutral plane shift and voltage kickback effects. However, it cannot solve the problem of flux weakening.