TABLE OF CONTENTS The previous sections provided a brief description of the major constructional components of an electrical machine and the materials of which they are made. The difference between the structure for assembly and for reliability will be described in Chapter 3.
In this section the detailed structure for assembly of the electrical machine is discussed and the effect of different types of machine upon it. This structure is exemplified by Figure 2.10. Note the similarity between this 4 kW induction motor and the 125 MVA synchronous generator shown in Figure 2.2(a).
This structure is also presented in tabular form in Table 2.3 and this will form the basis for considering the faults in machines later in the chapter. Note that generators require an exciter to provide the field current for their rotor. They generally have their exciters mounted on the shaft of the main machine and a large generator can have a pilot exciter and main exciter. The main exciter is clearly visible on the left in Figures 2.1 and 2.2(a), and the pilot exciter is also visible in Figure 2.2(a) between the main exciter and the main generator. Therefore a generator may consist of two or even three electrical machines on the same shaft. This is important when carrying out a failure modes and effects...
