© 2006 by Taylor & Francis Group, LLC
2-1
2
Principles of Electric
Generators
2.1
The Three Types of Electric Generators............................2-1
2.2
Synchronous Generators.....................................................2-4
2.3
Permanent Magnet Synchronous Generators ...................2-8
2.4
The Homopolar Synchronous Generator........................2-11
2.5
Induction Generator .........................................................2-13
2.6
The Wound Rotor (Doubly Fed) Induction
Generator (WRIG)............................................................2-15
2.7
Parametric Generators ......................................................2-17
The Flux Reversal Generators • The Transverse Flux Generators
(TFGs) • Linear Motion Alternators
2.8
Electric Generator Applications .......................................2-26
2.9
Summary............................................................................2-26
References .....................................................................................2-28
The extremely large power/unit span, from milliwatts to hundreds of megawatts (MW) and more, and
the wide diversity of applications, from electric power plants to car alternators, should have led to
numerous electric generator configurations and controls. And, so it did. To bring order to our presen-
tation, we need some classifications.
2.1 The Three Types of Electric Generators
Electric generators may be classified many ways, but the following are deemed as fully representative:
• By principle
• By application domain
The application domain implies the power level. The classifications by principle unfolded here include
commercial (widely used) types together with new configurations, still in the laboratory (although
advanced) stages.
By principle, there are three main types of electric generators:
• Synchronous (Figure 2.1)
• Induction (Figure 2.2)
• Parametric, with magnetic anisotropy and permanent magnets (Figure 2.3)
Parametric generators have in most configurations doubly salient magnetic c