What are the different types of dc generators ?

DC Generators are characterized by the method in which the flux is produced in the magnetizing circuit ( Field Winding ) of the DC generator. The flux required for the DC Generator is produced by

1.    A Permanent magnet

2.    Field Coils excited by the external source

3.    Field Coils excited by the same source.

Based on the method of excitation flux produced DC Generators are Characterized by

Separately Excited DC Generator:

In Separately excited DC Generator the field winding excitation current (which produces the flux) of the DC Generator is controlled by the External source such as battery or current from a small DC machine.

Series Wound Generator:

In Series Wound Generator the field winding of the DC Generator is connected in series of the armature winding of the DC machine. The current which flows out from the DC Generator through the armature winding the same current flow through the series field winding of the DC Generator. Series field winding consists of thick coils of lesser turns.

Shunt Wound Generator:

In Shunt wound Generator the field winding of the DC Generator is connected in parallel to the armature winding of the DC Generator. In Shunt type of construction the current produced at the armature is divided between the load and field winding. Some part of the current flow through the field winding and remaining through the load. Shunt field winding consists of high resistance winding with thin coils of more turns

Compound Wound Generator:

Compound wound generators contain both series and shunt type of field windings. They are connected as long shunt and short shunt. In long shunt the shunt field winding is connected parallel to the series winding and armature winding. In Short shunt type of arrangement the shunt field winding will be placed just parallel to the armature winding alone. This type of machines has the both the characteristics of series wound machine and shunt wound machine.