Salient pole generators

Synchronous AC machines have a stator similar to the asynchronous machines, which has usually a three-phase stator winding. Whereas there are two types of rotor structures round cylindrical rotor and salient pole rotor as illustrated schematically in Fig. 5.6. The rotor field is generated by permanent magnets or a DC current winding, as reported in the same figure. In the first case they are called permanent-magnet synchronous AC machines. 

The Power Versus Angle Chart of a Salient Pole Generator... 

The rotor of generators may be either cylindricaT or salient in construction. Synchronous motors nearly always have salient pole rotors. Machines with four or more poles are always of the salient pole rotor type. Cylindrical pole rotors are used for two-pole generators, and these generators are usually driven by steam or gas turbines at 3600 rpm for 60 Hz or 3000 rpm for 50 Hz operation and have power output ratings above 30 megawatts. 

The remaining discussion in this chapter, up to sub-section 3.9, will concentrate on salient pole machines with an emphasis on generators. 

THE POWER VERSUS ANGLE CHART OF A SALIENT POLE GENERATOR... 

Figure 3.4 Operating chart of a two-axis salient pole generator.

Short-circuit current decrement for a salient pole generator that has a high armature time... 

Salient pole generators nsed with gas-tnrbine drivers can tolerate NFS currents up to 40% of full-load current, when defined by -... 

The main exciter (see Fig. G-13) is a multipole synchronous generator with salient poles in the stator. 

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