11-07-2012, 03:05 PM
Power. Generation Committee
Power. Generation.pdf (Size: 1.84 MB / Downloads: 21)
INTRODUCTION
Wind generating devices and systems seem to be
receiving increasing attention from utility planning
engineers. Several wind generation schemes have been
proposedseach having its own advantages and disadvantages.
The category of variable speed constant frequency
devices (VSCF) includes schemes such as AC-DC-AC
(ADA) conversion, Frequency Down Conversion (FDC)
and Power Moddlation and Demodulation conversion. The
ADA, according to T.S.Jayah Devaiah [1], has cost
problems. Tne FDC scheme proposed by Allison,Ramakumar,
and Hughes [2] , also called the ARH, needs a rotational
frequency of at least ten times the desired line
frequency ; a rotational speed of around 6000 to 10000
rpm is required to reduce the DC and harmonics contents.
Matching the ACCM to a Wind Turbine
A desirable operating strategy of an ACCM based
wind generating system would aim at extracting the
maximum power available in the wind stream at all
times. Figure 8 shows typical characteristics of a wind turbine. Since it is not practical to vary the
turbine speed to track the points of maximum power on the turbine characteristics, it becomes necessary to
match the turbine and the ACCM characteristics to implement the desirable strategy.
CONCLUSIONS
A method of defining the feasible operating region
of a three phase AC Commutator Machine as a wind generator
on a distribution system has been introduced. A
strategy can be adopted which would be satisfactory to
both the utility and customer. In this respect, the
flexibility of this type of machine makes it a viable
candidate for wind generation systems.