Abstract:
Generation of electricity from the wind is becoming increasing popular as an
environmentally responsible resource. Current methods for generating electricity from
the wind involve the use of fixed-speed generators. However, the use of variable-speed
generators increases the amount of energy that can be extracted from the wind.
Most variable-speed technologies require processing large amounts power
electronically. In large utility-scale generation systems the added cost of the power
electronics may make variable-speed generation too expensive. A reduction in the size
of the power electronics is achieved when using the brushless doubly-fed machine.
A proof-of-concept system has been developed to evaluate not only the
advantages of variable-speed technology, but the advantages of using the brushless
doubly-fed machine. The prototype system uses a two-bladed turbine with a diameter
of 2.75 meters. The prototype system produces a maximum of 1500 watts in wind
speeds ranging from 0 to 40 miles per hour.
Experimental data illustrates the performance of the machine over a wide range
of power levels. The machine exhibits satisfactory efficiency. Experimental results
show that converter rating of the prototype system is one-fifth of that of a conventional
variable-speed system.
The proof-of-concept system shows that the brushless doubly-fed machine has
superior features as compared to other systems. Future research needs to evaluate its
use in a utility-scale environment.
