Low cost wind energy conversion system based on the discontinuous conduction mode three-phase semi-controlled rectifier

This study introduces a low-cost topology used in a wind energy conversion system with efficient power control in order to meet battery charge requirements. The proposed structure is based on a high-frequency three-phase semi-controlled rectifier operating in the discontinuous conduction mode associated with a buck converter. The system comprises three control loops, which limit the current and voltage ratings to the maximum values allowed by the batteries and also regulate the voltage across the intermediate dc link. In addition, a novel maximum power point tracking algorithm that intends to maximise the power extracted from the wind turbine/generator/converter association is proposed. The principle of the proposed technique is based on a modified version of power signal feedback algorithm, where a given power level can be extracted from the wind turbine for each value of the mechanical speed. However, since the optimal power curve is not exactly known and temperature causes considerable variations in the optimal power curve, a method to search the best match is proposed. Experimental results from a 300-W prototype are presented and discussed.