D.C. chopper-driven separately-excited D.C. machine in braking mode (IM-ETR-003)

The series-excited d.c. machine has serious disadvantages when used for braking purposes. These disadvantages occur due to the unstable nature of a series (self)-excited generator. These disadvantages are discussed below and, as a consequence, it is concluded that a series- excited machine used as a brake is unsuitable for Railway...