Separately excited generator
Now that we have learned some basic facts about dc generators, we can study the various types and their properties. Thus, instead of using permanent magnets to create the magnetic field, we can use a pair of electromagnets, called field poles, as shown in Fig. When the dc field current in such a generator is supplied by an independent source (such as a storage battery or another generator, called an exciter), the generator is said to be separately excited. Thus, in Fig. the dc source connected to terminals a and b causes an exciting current ig to flow. If the armature is driven by a motor or a diesel engine, a voltage E0, appears between brush terminals x and y. |
