Page 251 - Fluid Power Engineering

218 Chapter Te n

DFIG and Other
Induction Generators DDSG DDPM
Ability to handle wind Gusts lead to Same as DDSG
gusts is limited. Gusts increased speed while
cause significant keeping torque within
increase in torque. limit. Energy from
gusts is converted to
electric energy.
rpm of generator is rpm is in the range of Same as DDSG
large 1800/3600 rpm 15 to 30 rpm; so
for 60 Hz or torque is large
1500/3000 rpm for
50 Hz; so torque is
smaller
Small power Large rectifiers and Same as DDSG
electronics converters inverters are required
are required to to convert all power to
manage rotor circuit DC and then to AC at
grid frequency. High
frequency harmonics
are produced which
may be mitigated by
filters.
Compact generator, Large generator Material cost of
but complicated power requires precision magnets is high, and
electronics manufacturing and assembly is
assembly to maintain complicated by
uniformly small air gap requirement for small
air gap

∗ Hau, E., von Renouard, H. Wind Turbines: Fundamentals, Technologies, Application,
Economics, New York, Springer, 2005.
TABLE 10-2 Comparison of Three Variable-Speed Generators (Conitnued)

References
1. Richardson,D.RotatingElectricMachineryandTransformerTechnology,Reston
Publ. Co., Reston, VA, 1978.
2. Bhadra, S. N., Kastha, D., and Banerjee, S. Wind Electrical Systems, Oxford
University Press, New Delhi, 2005.
3. Quaschning, V. Understanding Renewable Energy Systems, EarthScan,
London, 2005.
4. Freris, L., and Infield, D. Renewable Energy in Power Systems, Wiley, New
York, 2008.