Comparative Analysis for Small-Sized Controllable Wind Systems

A wind system is designed to operate with a maximum efficiency at a given wind speed. With the use of appropriate mechanisms one can improve the efficiency at different speeds as well as widen the operational range of the system; the controllable pitch angle rotor is, in general, used for this. In order to maximize the produced energy, an alternative is the use of a controllable load, which can be achieved by changing the generator field current. This seems to be an attractive system for small units and for regions with low wind speed. In this paper a comparative analysis for a basic system, a pitch-controllable, and a field-controllable system is made, using a numerical simulation.