In this type, the part of the field winding is connected in parallel with armature and part in series with the armature. Both series and shunt field windings are mounted on the same poles. Depending upon the connection of shunt and series field winding, compound generator is further classified as : i) Long shunt compound generator, ii) Short shunt compound generator.
|Fig. 1 Long shunt compound generator|
In this type, shunt field winding is connected, only across the armature, excluding series field winding as shown in the Fig. 2.
|Fig. 2 Short shunt compound generator|
It is mentioned earlier that the two windings, shunt and series field are wound on the same pole. Depending on the direction of winding on the pole, two fluxes produced by shunt and series field may help or may oppose each other. This facts decides whether generator is cumulative or differential compound. If the two fluxes help each other as shown in Fig. 3 the generator is called cumulative compound generator.
|Fig. 3 Cumulative compound generator|
?se = Flux produced by series field winding.
|Fig. 4 Differential compound generator|